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Green roof

A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage and irrigation systems. Container gardens on roofs, where plants are maintained in pots, are not generally considered to be true green roofs, although this is debated. Rooftop ponds are another form of green roofs which are used to treat greywater. Vegetation, soil, drainage layer, roof barrier and irrigation system constitute the green roof.

Green roofs serve several purposes for a building, such as absorbing rainwater, providing insulation, creating a habitat for wildlife, increasing benevolence, and decreasing stress of the people around the roof by providing a more aesthetically pleasing landscape, and helping to lower urban air temperatures and mitigate the heat island effect. Green roofs are suitable for retrofit or redevelopment projects as well as new buildings and can be installed on small garages or larger industrial, commercial and municipal buildings. They effectively use the natural functions of plants to filter water and treat air in urban and suburban landscapes. There are two types of green roof: intensive roofs, which are thicker, with a minimum depth of 12.8 cm, and can support a wider variety of plants but are heavier and require more maintenance, and extensive roofs, which are shallow, ranging in depth from 2 to 12.7 cm, lighter than intensive green roofs, and require minimal maintenance.

The term green roof may also be used to indicate roofs that use some form of green technology, such as a cool roof, a roof with solar thermal collectors or photovoltaic panels. Green roofs are also referred to as eco-roofs, oikosteges, vegetated roofs, living roofs, greenroofs and VCPH (Horizontal Vegetated Complex Partitions)

Thermal reduction and energy conservation
Green roofs improve and reduce energy consumption. They can reduce heating by adding mass and thermal resistance value, and can reduce the heat island by increasing evapotranspiration. A 2005 study by Brad Bass of the University of Toronto showed that green roofs can also reduce heat loss and energy consumption in winter conditions. A modeling study found that adding green roofs to 50 percent of the available surfaces in downtown Toronto would cool the entire city by 0.2 to 1.4 F-change.

Through evaporative cooling, a green roof reduces cooling loads on a building by fifty to ninety percent, especially if it is glassed-in so as to act as a terrarium and passive solar heat reservoir.

A concentration of green roofs in an urban area can even reduce the city's average temperatures during the summer, combating the urban heat island effect. Traditional building materials soak up the sun's radiation and re-emit it as heat, making cities at least 4 C-change hotter than surrounding areas. On Chicago's City Hall, by contrast, which features a green roof, roof temperatures on a hot day are typically 1.4 – cooler than they are on traditionally roofed buildings nearby. Green roofs are becoming common in Chicago, as well as in Atlanta, Portland, and other United States cities, where their use is encouraged by regulations to combat the urban heat-island effect. Green roofs are a type of low impact development. In the case of Chicago, the city has passed codes offering incentives to builders who put green roofs on their buildings. The Chicago City Hall green roof is one of the earliest and most well-known examples of green roofs in the United States; it was planted as an experiment to determine the effects a green roof would have on the microclimate of the roof. Following this and other studies, it has now been estimated that if all the roofs in a major city were greened, urban temperatures could be reduced by as much as 7 C-change.

Water management
Green roofs can reduce stormwater runoff via water-wise gardening techniques. Green roofs play a significant role in retrofitting the Low Impact Development (LID) practices in urban areas. A study presented at the Green Roofs for Healthy Cities Conference in June 2004, cited by the EPA, found water runoff was reduced by over 75% during rainstorms. Water is stored by the roof's substrate and then taken up by the plants, from which it is returned to the atmosphere through transpiration and evaporation.

Green roofs decrease the total amount of runoff and slow the rate of runoff from the roof. It has been found that they can retain up to 75% of rainwater, gradually releasing it back into the atmosphere via condensation and transpiration, while retaining pollutants in their soil. Many green roofs are installed to comply with local regulations and government fees, often regarding stormwater runoff management. In areas with combined sewer-stormwater systems, heavy storms can overload the wastewater system and cause it to flood, dumping raw sewage into the local waterways. Often, phosphorus and nitrogen are in this category of environmentally harmful substances even though they are stimulating to the growth of plant life and agriculture. When these substances are added to a system, it can create mass biological activity since they are considered limiting factors of plant growth and by adding more of them to a system, it allows for more plant growth.

Ecological benefits
Green roofs create natural habitat as part of an urban wilderness. Even in high-rise urban settings as tall as 19 stories, it has been found that green roofs can attract beneficial insects, birds, bees and butterflies. A recent list of the bee species recorded from green roofs (worldwide) highlights both the diversity of species, but also the (expected) bias towards small ground-nesting species (Hofmann and Renner, 2017). Rooftop greenery complements wild areas by providing stepping stones for songbirds, migratory birds and other wildlife facing shortages of natural habitat. Bats have also been reported to be more active over green roofs due to the foraging opportunities these roofs provide. Research at the Javits Center green roof in New York, NY, has shown a correlation between higher numbers of certain insects on the roof, particularly moths, with an increased amount of bat foraging activity.

Green roofs also serve as a green wall, filtering pollutants and carbon dioxide out of the air, helping to lower rates of diseases such as asthma. They can also filter pollutants and heavy metals out of rainwater.

Carbon sequestration
An additional environmental benefit of a green roof is the ability to sequester carbon. Carbon is the main component of plant matter and is naturally absorbed by plant tissue. The carbon is stored in the plant tissue and the soil substrate through plant litter and root exudates. A study on green roofs in Michigan and Maryland found the above ground biomass and below ground substrate stored on average between 168 g C m−2 and 107 g C m−2. Variations occurred among the different species of plant used. Substrate carbon content averaged 913 g C m−2 and after the subtraction of the original carbon content the total sequestration was 378 g C m−2. The sequestration can be improved by changing plant species, increasing substrate depth, substrate composition, and management practices. In a study done in Michigan above ground sequestration ranged from 64 g C m−2 to 239 g C m−2 for S. acre and S album. Also, by increasing the substrate depth would allow for more area of carbon storage and diversify the types of plants with greater potential of carbon storage. The direct carbon sequestration techniques and methods can be measured and accounted for. Green roofs also indirectly reduce CO2 given off by power plants through their ability to insulate buildings. Buildings in the US account for 38% of the total carbon dioxide emissions. A model supported by the U.S. Department of Energy found a 2 percent reduction in electricity consumption and 9-11% reduction in natural gas when implementing green roofs.

Other

 * Help to insulate a building for sound; the soil helps to block lower frequencies and the plants block higher frequencies
 * If installed correctly many living roofs can contribute to LEED points
 * Increase agricultural space
 * Green roofs not only retain rainwater, but also moderate the temperature of the water and act as natural filters for any of the water that happens to run off.

Costs and financial benefits

A properly designed and installed extensive green-roof system can cost 108 - 248 $/m2 while an intensive green roof costs 355 - 2368 $/m2 However, since most of the materials used to build the green roof can be salvaged, it is estimated that the cost of replacing a green roof is generally one third of the initial installation costs.

With the initial cost of installing a green roof in mind, there are many financial benefits that accompany green roofing.
 * Green roofing can extend the lifespan of a roof by over 200% by covering the waterproofing membrane with growing medium and vegetation, this shields the membrane from ultra-violet radiation and physical damage. Further, Penn State University's Green Roof Research Center expects the lifespan of a roof to increase by as much as three times after greening the roof.
 * It is estimated that the installation of a green roof could increase the real estate value of an average house by about 7%.
 * Reduction in energy use is an important property of green roofing. By improving the thermal performance of a roof, green roofing allows buildings to better retain their heat during the cooler winter months while reflecting and absorbing solar radiation during the hotter summer months, allowing buildings to remain cooler.  A study conducted by Environment Canada found a 26% reduction in summer cooling needs and a 26% reduction in winter heat losses when a green roof is used. With respect to hotter summer weather, green roofing is able to reduce the solar heating of a building by reflecting 27% of solar radiation, absorbing 60% by the vegetation through photosynthesis and evapotranspiration, and absorbing the remaining 13% into the growing medium. Such mitigation of solar radiation has been found to reduce building temperatures by up to 20 C-change and reduce energy needs for air-conditioning by 25% to 80%.  This reduction in energy required to cool a building in the summer is accompanied by a reduction in energy required to heat a building in the winter, thus reducing the energy requirements of the building year-round which allows the building temperature to be controlled at a lower cost.
 * Depending on the region in which a green roof is installed, incentives may be available in the form of stormwater tax reduction, grants, or rebates. The regions where these incentives will most likely be found are areas where failing storm water management infrastructure is in place, urban heat island effect has significantly increased the local air temperature, or areas where environmental contaminants in the storm water runoff is of great concern. An example of such an incentive is a one-year property tax credit is available in New York City, since 2009, for property owners who green at least 50% of their roof area.

Disadvantages

The main disadvantage of green roofs is that the initial cost of installing a green roof can be double that of a normal roof. Depending on what kind of green roof it is, the maintenance costs could be higher, but some types of green roof have little or no ongoing cost. Some kinds of green roofs also place higher demands on the waterproofing system of the structure, both because water is retained on the roof and due to the possibility of roots penetrating the waterproof membrane. Another disadvantage is that the wildlife they attract may include pest insects which could easily infiltrate a residential building through open windows.

The additional mass of the soil substrate and retained water places a large strain on the structural support of a building. This makes it unlikely for intensive green roofs to become widely implemented due to a lack of buildings that are able to support such a large amount of added weight as well as the added cost of reinforcing buildings to be able to support such weight. Some types of green roofs do have more demanding structural standards especially in seismic regions of the world. Some existing buildings cannot be retrofitted with certain kinds of green roofs because of the weight load of the substrate and vegetation exceeds permitted static loading. The weight of a green roof caused the collapse of a large sports hall roof in Hong Kong in 2016. In the wake of the disaster numerous other green roofs around the territory were removed.

Green roofs require significantly more maintenance and maintenance energy compared to a standard roof. Standard maintenance include removing debris, controlling weeds, deadhead trimming, checking moisture levels, and fertilizing. The maintenance energy use for green roofs has many variables including: climate, intensity of rainfall, type of building, type of vegetation, and external coatings. The most significant effect comes from scarce rainfall which will increase the maintenance energy due to the watering required. During a 10-year roof maintenance cycle a house with a green roof requires more retrofit embodied energy than a house with a white roof. The individual components of a green roof have implications during the manufacturing process have additional implications compared to a conventional roof. The embodied energy for green roof components are 23.6 kg/m2 of green roof. This value is equivalent to 6448 g C m−2 which is significantly greater than 378 g C m−2. Criteria for waste management practices when green roofs reach their end-of-life remain uncodified.

Both sod roofs and LWA-based (Lightweight Aggregates) roofs have been found to have a negative impact on the quality of their resulting runoff.

Types
Green roofs can be categorized as intensive, semi-intensive, or extensive, depending on the depth of planting medium and the amount of maintenance they need. Extensive green roofs traditionally support 10 - 25 psf of vegetation while intensive roofs support 80 - 150 psf of vegetation. Traditional roof gardens, which require a reasonable depth of soil to grow large plants or conventional lawns, are considered intensive because they are labour-intensive, requiring irrigation, feeding, and other maintenance. Intensive roofs are more park-like with easy access and may include anything from kitchen herbs to shrubs and small trees.

Extensive green roofs, by contrast, are designed to be virtually self-sustaining and should require only a minimum of maintenance, perhaps a once-yearly weeding or an application of slow-release fertiliser to boost growth. Extensive roofs are usually only accessed for maintenance. They can be established on a very thin layer of soil (most use specially formulated composts): even a thin layer of rockwool laid directly onto a watertight roof can support a planting of Sedum species and mosses. Some green roof designs incorporate both intensive and extensive elements. To protect the roof, a waterproofing membrane is often used, which is manufactured to remain watertight in extreme conditions including constant dampness, ponding water, high and low alkaline conditions and exposure to plant roots, fungi and bacterial organisms.

Advances in green roof technology have led to the development of new systems that do not fit into the traditional classification of green roof types. Comprehensive green roofs bring the most advantageous qualities of extensive and intensive green roofs together. Comprehensive green roofs support plant varieties typically seen in intensive green roofs at the depth and weight of an extensive green roof system.

Another important distinction is between pitched green roofs and flat green roofs. Pitched sod roofs, a traditional feature of many Scandinavian buildings, tend to be of a simpler design than flat green roofs. This is because the pitch of the roof reduces the risk of water penetrating through the roof structure, allowing the use of fewer waterproofing and drainage layers.

History
In ancient times green roofs consisted of cave-like structures or sod roofs covered with earth and plants commonly used for agriculture, dwelling, and ceremonial purposes. These early shelters provided protection from the elements, good insulation during the winter months, and a cool location in the summer. Unfortunately for modern conveniences, these were neither waterproof nor was there any system to keep out unwanted burrowing wildlife.

Modern green roofs, which are made of a system of manufactured layers deliberately placed over roofs to support growing medium and vegetation, are a relatively new phenomenon. However, green roofs or sod roofs in northern Scandinavia have been around for centuries. The modern trend started when green roofs were developed in Germany in the 1960s, and has since spread to many countries. Today, it is estimated that about 10% of all German roofs have been "greened".

A number of European Countries have very active associations promoting green roofs, including Germany, Switzerland, the Netherlands, Norway, Italy, Austria, Hungary, Sweden, the UK, and Greece. Germany was the first country to start developing green roof systems and market them on a large scale. The City of Linz in Austria has been paying developers to install green roofs since 1983, and in Switzerland, it has been a federal law since the late 1990s. In the UK, their uptake has been slow, but a number of cities have developed policies to encourage their use, notably London and Sheffield.

Green roofs are also becoming increasingly popular in North America, although they are not as common as in some parts of Europe. Numerous North American cities offer tax incentives to developers who integrate green roofs in their buildings. Toronto and San Francisco legally mandate new buildings to include green roofs.

Rooftop water purification is also being implemented in green roofs. These forms of green roofs are actually treatment ponds built into the rooftops. They are built either from a simple substrate (as being done in Dongtan ) or with plant-based ponds. Plants used include calamus, Menyanthes trifoliata, Mentha aquatica, etc. )

Several studies have been carried out in Germany since the 1970s. Berlin is one of the most important centers of green roof research in Germany. Particularly in the last 10 years, much more research has begun. About ten green roof research centers exist in the US and activities exist in about 40 countries. In a recent study on the impacts of green infrastructure, in particular green roofs in the Greater Manchester area, researchers found that adding green roofs can help keep temperatures down, particularly in urban areas: "adding green roofs to all buildings can have a dramatic effect on maximum surface temperatures, keeping temperatures below the 1961–1990 current form case for all time periods and emissions scenarios. Roof greening makes the biggest difference…where the building proportion is high and the evaporative fraction is low.  Thus, the largest difference was made in the town centers".

Brown roofs
Industrial brownfield sites can be valuable ecosystems, supporting rare species of plants, animals and invertebrates. Increasingly in demand for redevelopment, these habitats are under threat. "Brown roofs", also known as "biodiverse roofs", can partly mitigate this loss of habitat by covering the flat roofs of new developments with a layer of locally sourced material. Construction techniques for brown roofs are typically similar to those used to create flat green roofs, the main difference being the choice of growing medium (usually locally sourced rubble, gravel, soil, etc...) to meet a specific biodiversity objective. In Switzerland, it is common to use alluvial gravels from the foundations; in London, a mix of brick rubble and some concrete has been used.

The original idea was to allow the roofs to self-colonise with plants, but they are sometimes seeded to increase their biodiversity potential in the short term. Such practices are derided by purists. The roofs are colonised by spiders and insects (many of which are becoming extremely rare in the UK as such sites are developed) and provide a feeding site for insectivorous birds. Laban, a centre for contemporary dance in London, has a brown roof specifically designed to encourage the nationally rare black redstart. A green roof, 160 m above ground level, and claimed to be the highest in the UK and Europe "and probably in the world" to act as nature reserve, is on the Barclays Bank HQ in Canary Wharf. Designed combining the principles of green and brown roofs, it is already home to a range of rare invertebrates.

ASLA Award Green Roof Projects
2017 Award: Seeding Green Roofs for Greater Biodiversity and Lower Costs, Lincoln, NE, USA. Richard Sutton

2013 Award: Green Roof Innovation Testing Laboratory, Toronto, Ontario, Canada. John H. Daniels, Brooklyn Botanic Garden Visitors Center, Brooklyn. HMWhite, and NYC Parks Green Roof: A Living Laboratory for Innovative Green Roof Design, New York, NY. NYC Parks

2012 Award: Lafayette Greens: Urban Agriculture, Urban Fabric, Urban Sustainability, Detroit. Kenneth Weikal Landscape Architecture 200 Fifth Avenue, NYC. Landworks Studio, Inc.

2011 Award: Manassas Park Elementary School Landscape, Manassas Park, VA. Siteworks]

2009 Award: California Academy of Sciences, San Francisco, CA. SWA Group, Changi Airport Terminal 3 Interior Landscape, Singapore. Tierra Design (S) Pte Ltd, Corporate Headquarters, San Francisco, CA. OLIN, Macallen Building, South Boston, MA. Landworks Studio, Inc., and Museo del Acero Horno3, Monterrey, Mexico. Surfacedesign Inc.+ Harari arquitectos

2008 Award: Gannett/USA Today Headquarters, McLean, Virginia. Michael Vergason Landscape Architects, Ltd.

2007 Award: Washington Mutual Center Roof Garden, Seattle, Washington. Phillips Farevaag Smallenberg

2002 Award: Chicago City Hall Green Roof, Chicago, Illinois. David Yocca

Australia
Green roofs have been increasing in popularity in Australia over the past 10 years. Some of the early examples include the Freshwater Place residential tower in Melbourne (2002) with its Level 10 rooftop Half Acre Garden, CH2 building housing the Melbourne City Council (2006) – Australia's first 6-star Green Star Design commercial office building as certified by the Green Building Council of Australia, and Condor Tower (2005) with a 75 m2 lawn on the 4th floor.

Since 2008, city councils and influential business groups in Australia have become active promoting the benefits of green roofs. "The Blueprint to Green Roof Melbourne" is one program being run by the Committee for Melbourne. In 2010, the largest Australian green roof project was announced. The Victorian Desalination Project will have a "living tapestry" of 98,000 Australian indigenous plants over a roof area spanning more than 26000 m2. The roof will form part of the desalination plant's sophisticated roof system, designed to blend the building into the landscape, and provide acoustic protection, corrosion resistance, thermal control, and reduced maintenance.

In June 2014 ecological artist Lloyd Godman, with structural engineer Stuart Jones and environmental scientist Grant Harris collaborated to install an experiment using Tillandsia plants in extreme outdoor conditions at levels 92, 91, 65 and 56 on Eureka Tower in Melbourne, Australia. The selected air plants are extremely light, and are able to grow with no soil or watering system, and the plants have been checked at regular intervals since their installation and are still growing and flowering. One species; Tillandsia bergeri, has grown from a single shoot to several thriving colonies.

The project is now titled Tillandsia SWARM and has been expanded to include many other buildings across Australia, including Federation Square, National Gallery of Victoria and Essendon Airport. Godman has also experimented with Tillandsia plant screens that can be moved across skylights to create shade in summer and to allow in sun during winter. Temperature readings taken on a 40°C day in summer revealed that the surface temperature on the roof had reached 84°C, while the shadows cast by the plants had reduced the surface temperature on the roof to 51°C.

Canada
The city of Toronto approved a by-law in May 2009 mandating green roofs on residential and industrial buildings. There is criticism from Green Roofs for Healthy Cities that the new laws are not stringent enough, since they will only apply to residential building that are a minimum of six stories high. By 31 January 2011, industrial buildings were required to render 10% or 2000 m2 of their roofs green. Toronto City Hall's Podium roof was renovated to include a 32000 sqft rooftop garden, the largest publicly accessible roof in the city. The green roof was opened to the public in June 2010. Many green roofs in Canada also use sustainable rainwater harvesting practices.

In 2008, the Vancouver Convention Centre installed a 6 acre living roof of indigenous plants and grasses on its West building, making it the largest green roof in Canada. The new Canadian War Museum in Ottawa, opened in 2005, also features a grass-covered roof.

During the renovation of the Hamilton City Hall in Hamilton, Ontario that spanned from 2007 to 2010, many efforts were taken to enhance the environmentally friendly nature of the structure, which included the addition of a grass-covered roof.

Simon Fraser University's Burnaby campus contains a substantial number of green roofs.

Canada's first LEED Platinum V4 Home in Wakefield QC, EcoHome's Edelweiss House, has a living Green Roof which is sloped at 12 degrees.

Costa Rica
Living green roofs have been built and grown at Saint Michael's Sustainable Community since 2012. Native plants, mostly flowers chosen for the environment, maximum shade and mass provide a colorful and functional living roof. The community has the largest number of green roofs in the country.

Egypt
In Egypt, soil-less agriculture is used to grow plants on the roofs of buildings. No soil is placed directly on the roof itself, thus eliminating the need for an insulating layer; instead, plants are grown on wooden tables. Vegetables and fruit are the most popular candidates, providing a fresh, healthy source of food that is free from pesticides.

A more advanced method, (aquaponics), being used experimentally in Egypt, is farming fish next to plants in a closed cycle. This allows the plants to benefit from the ammonia excreted by the fish, helping the plants to grow better and at the same time eliminating the need for changing the water for the fish, because the plants help to keep it clean by absorbing the ammonia. The fish also get some nutrients from the roots of the plants.

Finland
In Finland, green roofs are still scarce. Some experimental green roofs have been built in big cities. However, the capital city of Helsinki has published guidelines for enhancing the building of green roofs in the city. There is on-going research on the topic as the conditions in the southern Europe are very different from those in the north and knowledge acquired there can't be directly applied to colder climates. The fifth dimension – Green roofs and walls in urban areas -research program aims to produce high-level scientific and broadly applicable knowledge on optimal green roof and -wall solutions in Finland.

France
In France, an 8000 m2 extensive, cable-supported green roof has been created on the International School in Lyon. Another huge green roof of roughly 8000 m2 has been incorporated into the new museum L'Historial de la Vendée which opened in June 2006 at Les Lucs-sur-Boulogne.

Germany
Long-held green roof traditions started in the early industrialization period more than 100 years ago exist in Germany. In the 1970s, green roof technology was elevated to the next level. Serious storm-water issues made cities think about innovative solutions, preferably with living plants. Modern green roof technology with high performance, lightweight materials were used to grow hardy vegetation even on roofs that can hardly support any additional load. In the 1980s modern green roof technology was common knowledge in Germany while it was practically unknown in any other country in the world. In Stuttgart, with one of the most innovative Department of Parks and Recreation and with the world's oldest horticultural Universities, modern green roof technology was perfected and implemented on a large scale. By the early 2000s, Germany had laws mandating that many metropolitan areas have green roofs.

With the first green roof industry boom in Germany there were quality issues recorded. The FLL formed a committee that is focused on modern green roof technology. FLL stands for Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V. (German Landscape Research, Development and Construction Society). The FLL is an independent non-profit organization. It was founded in 1975 by eight professional organizations for "the improvement of environmental conditions through the advancement and dissemination of plant research and its planned applications". The FLL green roof working group is only one of 40 committees which have published a long list of guidelines and labor instructions. Some of these guidelines also available in English including the German FLL-Guideline for the Planning, Execution and Upkeep of Green-Roof Sites. The results of the research and synthesis done by FLL members are constantly updated and promulgated utilizing the same principles which govern the compilation of DIN standards and are published as either guiding principles or labor instructions.

The current Green Roof Guideline was published in 2011. Today most elements of the German FLL are part of standards and guidelines around the world (FM Global, ASTM, NRCA, SPRI etc.).

Fachvereinigung Bauwerksbegrünung (FBB) was founded in 1990 as the second green roof association after DDV (Deutscher Dachgaertner Verband) in 1985. FBB was founded as an open forum for manufacturers and planners, merchants and operators in 1990. The organization was born from the then-visionary idea of understanding the relationship between nature and constructions not as oppositional, but as an opportunity. Both the green roofing and conventional roofing industries are equally represented. The FBB has developed to become an innovative lobbying group with a strong market presence, internationally known through its cooperation with other European associations. Today, approximately 100 member companies use the multifaceted services offered by FBB, which offers a greater degree of market expertise and competitiveness. "Kompetenz im Markt".

Today, about 10000000 m2 of new green roofs are being constructed each year. According latest studies about $3/4$ of these are extensive; the last $1/4$ are roof gardens. The cities with the most green roofs in Germany are Berlin and Stuttgart. Surveys about the status of regulation are done by the FBB. Nearly one third of all German cities have regulations to support green-roof and rain-water technology. Green-roof research institutions are located in several cities as including Hannover, Berlin, Geisenheim and Neubrandenburg.

Germany is the country with the most green roofs in the world as well as the country with the most advanced knowledge in modern green roof technology. Green roofs in Germany are part of the 2 –3 years apprentice educations system of landscaping professionals.

Greece
The Greek Ministry of Finance has now installed a green roof on the Treasury in Constitution Square in Athens. The so-called "oikostegi" (Greek – oiko,, meaning building-ecological, and stegi, pronounced staygee, meaning roof-abode-shelter) was inaugurated in September 2008. Studies of the thermodynamics of the roof in September 2008 concluded that the thermal performance of the building was significantly affected by the installation. In further studies, in August 2009, energy savings of 50% were observed for air conditioning in the floor directly below the installation. The ten-floor building has a total floor space of 1.4 ha. The oikostegi covers 650 sqft, equalling 52% of the roof space and 8% of the total floor space. Despite this, energy savings totalling €5,630 per annum were recorded, which translates to a 9% saving in air conditioning and a 4% saving in heating bills for the whole building. An additional observation and conclusion of the study was that the thermodynamic performance of the oikostegi had improved as biomass was added over the 12 months between the first and second study. This suggests that further improvements will be observed as the biomass increases still further. The study also stated that while measurements were being made by thermal cameras, a plethora of beneficial insects were observed on the roof, such as butterflies, honey bees and ladybirds. Obviously this was not the case before installation. Finally, the study suggested that both the micro-climate and biodiversity of Constitution Square, in Athens, Greece had been improved by the oikostegi.

Iceland
Sod roofs are frequently found on traditional farmhouses and farm buildings in Iceland.

Malaysia
Bus stops in Kuala Lumpur were fitted with green roofs in 2019.

Poland
Several cities in Poland have implemented policies and incentives to encourage the installation of green roofs, including Warsaw, Krakow, and Wroclaw. These policies have helped to increase the adoption of green roofs in the country, particularly in urban areas, where they are seen as an important tool for mitigating the environmental impacts of urbanization and improving the quality of life for city residents. The University of Warsaw green roof is one of the most impressive and well-known examples of green roofs in Poland. It covers an area of approximately 10,000 square meters and includes over 30,000 plants from more than 70 different species.

Singapore
Singapore installed a green roof on a bus in 2019 as part of an experiment led by researchers at the National University of Singapore. Green roofs on bus stops in Singapore were found to reduce ambient temperatures by up to 2C.

Switzerland
Switzerland has one of Europe's oldest green roofs, created in 1914 at the Moos lake water-treatment plant, Wollishofen, Zürich. Its filter tanks have 30000 m2 of flat concrete roofs. To keep the interior cool and prevent bacterial growth in the filtration beds, a drainage layer of gravel and a 15 cm layer of soil was spread over the roofs, which had been waterproofed with asphalt. A meadow developed from seeds already present in the soil; it is now a haven for many plant species, some of which are now otherwise extinct in the district, most notably 6,000 Orchis morio (green-winged orchid). More recent Swiss examples can be found at Klinikum 1 and Klinikum 2, the Cantonal Hospitals of Basel, and the Sihlpost platform at Zürich's main railway station.

Sweden
What is claimed to be the world's first green roof botanical garden was set up in Augustenborg, Malmö in May 1999. The International Green Roof Institute (IGRI) opened to the public in April 2001 as a research station and educational facility. (It has since been renamed the Scandinavian Green Roof Institute (SGRI), in view of the increasing number of similar organisations around the world.) Green roofs are well-established in Malmö: the Augustenborg housing development near the SGRI botanical garden incorporates green roofs and extensive landscaping of streams, ponds, and soak-ways between the buildings to deal with storm water run-off.

The new Bo01 urban residential development (in the Västra Hamnen (Western Harbour) close to the foot of the Turning Torso office and apartment block, designed by Santiago Calatrava) is built on the site of old shipyards and industrial areas, and incorporates many green roofs.

In 2012, the shopping mall Emporia with its 27000 m2 roof garden, was opened. The size of the roof garden is approximately equivalent to 4 soccer fields, which makes it one of the biggest green roof parks in Europe that is accessible to the public.

United Kingdom
In 2003 English Nature concluded that 'in the UK policy makers have largely ignored green roofs'. However, British examples can be found with increasing frequency. The Kensington Roof Gardens are a notable early roof garden which was built above the former Derry & Toms department store in Kensington, London in 1938. More recent examples can be found at the University of Nottingham Jubilee Campus, and in London at Sainsbury's Millennium Store in Greenwich, the Horniman Museum and at Canary Wharf. The Ethelred Estate, close to the River Thames in central London, is the British capital's largest roof-greening project to date. Toxteth in Liverpool is also a candidate for a major roof-greening project.

In the United Kingdom, intensive green roofs are sometimes used in built-up city areas where residents and workers often do not have access to gardens or local parks. Extensive green roofs are sometimes used to blend buildings into rural surroundings, for example by Rolls-Royce Motor Cars, who has one of the biggest green roofs in Europe (covering more than 32000 m2 on their factory at Goodwood, West Sussex.

The University of Sheffield has created a Green Roof Centre of Excellence and conducted research, particularly in a UK context, into green roofs. Nigel Dunnett of Sheffield University published a UK-centric book about green roofing in 2004 (updated 2008).

Fort Dunlop has the largest green roof in the UK since its redevelopment between 2004 and 2006.

The UK also has one of the most innovative food preparation facilities in Europe, the Kanes salad factory in Evesham. It is topped with a wildflower roof featuring nearly 90 species of wildflower and natural grasses. The seed mix was prepared in consultation with leading ecologists to try to minimise the impact on the local environment. The pre-grown wildflower blanket sits on top of a standing seam roof and is combined with solar panels to create an eco-friendly finish to the entire factory. The development also won the 2013 National Federation of Roofing Contractors Sustainable Roof Award for Green Roofing.

United States

One of the largest expanses of extensive green roof is to be found in the US, at Ford Motor Company's River Rouge Plant, Dearborn, Michigan, where 42000 m2 of assembly plant roofs are covered with sedum and other plants, designed by William McDonough; the $18 million assembly avoids the need of what otherwise would be $50 million worth of mechanical treatment facilities on site. Built over Millennium Park Garage, Chicago's 24.5 acre Millennium Park is considered one of the largest intensive green roofs. Other well-known American examples include Chicago's City Hall and the former Gap headquarters, now the headquarters of YouTube, in San Bruno, CA. The U.S. military has two major green roofs in the Washington, D.C. area: the U.S. Coast Guard headquarters (550000 sqft) and the Pentagon (180000 sqft).

An early green-roofed building (completed in 1971) is the 358000 sqft Weyerhaeuser Corporate Headquarters building in Federal Way, Washington. Its 5-story office roof system comprises a series of stepped terraces covered in greenery. From the air, the building blends into the landscape.

The largest green roof in New York City was installed in midtown Manhattan atop the United States Postal Service's Morgan Processing and Distribution Center. Construction on the 109000 sqft project began in September 2008, and was finished and dedicated in July 2009. Covered in native vegetation and having an expected lifetime of fifty years, this green roof will not only save the USPS approximately $30,000 a year in heating and cooling costs, but will also significantly reduce the amount of storm water contaminants entering the municipal water system.

In 2001, atop Chicago City Hall, the 38800 sqft roof gardens were completed, serving as a pilot project to assess the impact green roofs would have on the heat island effect in urban areas, rainwater runoff, and the effectiveness of differing types of green roofs and plant species for Chicago's climate. Although the rooftop is not normally accessible to the public, it is visually accessible from 33 taller buildings in the area. The garden consists of 20,000 plants of more than 150 species, including shrubs, vines and two trees. The green roof design team was headed by the Chicago area firm Conservation Design Forum in conjunction with noted "green" architect William McDonough. With an abundance of flowering plants on the rooftop, beekeepers harvest approximately 200 lb of honey each year from hives installed on the rooftop. Tours of the green roof are by special arrangement only. Chicago City Hall Green Roof won merit design award of the American Society of Landscape Architecture (ASLA) competition in 2002.

The 14000 sqft of outdoor space on the seventh floor of Zeckendorf Towers, formerly an undistinguished rooftop filled with potted plants, make up the largest residential green roof in New York. The roof was transformed in 2010 as part of Mayor Michael Bloomberg's NYC Green Infrastructure campaign, and supposedly serves to capture some of the rain that falls on it rather than letting it run off and contribute to flooding in the adjacent Union Square subway station.

Some cost can also be attributed to maintenance. Extensive green roofs have low maintenance requirements but they are generally not maintenance free. German research has quantified the need to remove unwanted seedlings to approximately 6 seconds/m2/year. Maintenance of green roofs often includes fertilization to increase flowering and succulent plant cover. If aesthetics are not an issue, fertilization and maintenance are generally not needed. Extensive green roofs should only be fertilized with controlled-release fertilizers in order to avoid pollution of the storm water. Conventional fertilizers should never be used on extensive vegetated roofs. German studies have approximated the nutrient requirement of vegetated roofs to 5 gN/m2. It is also important to use a substrate that does not contain too many available nutrients. The FLL guidelines specify maximum-allowable nutrient content of substrates.

One of the oldest American green roofs in existence is atop the Rockefeller Center in Manhattan, built in 1936. This roof was primarily an aesthetic undertaking for the enjoyment of the center's workers, and remains to this day, having been refurbished in 1986.

With the passage of Denver's Green Roof Initiative in the November 2017 elections, effective January 2018, new buildings or existing buildings meeting the initiative's thresholds are required to have rooftop gardens, optionally combined with solar photovoltaic panels.

Seattle is another city in which green roofs have been used on an increasing basis. This phenomenon is in large part due to efforts on behalf of the city to encourage green roofs through new and improved building codes. In 2006, the Seattle Green Factor program was approved. The program rewards the incorporation of landscaping in new building developments in an attempt to reduce stormwater runoff and associated pollution, stabilize temperatures, and create habitats for birds and insects. These changes were expanded in 2009 to recognize the specific stormwater benefits of green roofs, and to reward developers who used them accordingly.

By 2010, Seattle was home to approximately 8.25 acre of green roofs. Despite initial hiccups in the city stemming from weeds, lack of irrigation during dry summer months, and a need for continuous replanting, the project has continued to succeed as understanding around the best soils and plants and the need for monitoring and upkeep has increased. A 2010 survey of the green roofs in Seattle acknowledged that while the initial costs of implementing a green roof may deter businesses or homeowners, it is likely that green roofs actually preserve the roofing material and cut costs in the long run. In light of the success in Seattle, other cities such as Portland, Chicago, and Washington, D.C. have all made efforts to develop their own Green Factor programs.

The Seattle City Hall has led the way by implementing a green roof project that has involved the planting of more than 22,000 pots of sedum, fescue, and grass. The City hopes that the project can reduce the annual stormwater runoff for the building by 50 to 75 percent, which will in turn reduce damage to local watershed areas that provide habitats for native species such as salmon. The historic Union Stables building has used green roofs alongside other efficiency based changes to reduce stormwater runoff and decrease the building's energy use by 70 percent. The Park Place building in Seattle's downtown provides a leading example of the use of landscaping to recapture rain water with the hopes of cutting back spending on utilities.

Washington, D.C.

Washington, D.C., started implementing incentives for green roofs within their city at the beginning of the 21st century. In 2003, the Chesapeake Bay Foundation introduced a “green roof demonstration project” in combination with the D.C. Water and Sewer Authority. This program issued grants to several pilot green roofs, which would assist with the cost of construction for the building owner. From this project the city began to understand how beneficial these roofs could be and more programs were implemented over the years. In 2007, the Riversmart Rewards Program introduced a RiverSmart Rooftops Green Roof Rebate Program that would lend a $3 per square foot subsidy to potential green roof projects within the District. This culminated to assist 12 projects that year. A year later, the subsidy was raised to $5, incentivizing even more developers to use this program within their design. There is also possibility through the RiverSmart Rewards program for “residents and property owners to receive a significant discount on their water utility fees” if they install approved stormwater management features. In 2016, a rebate of $10-$15 per square feet was introduced, “promoting the voluntary installation of green roofs for the purpose of reducing stormwater runoff and pollutants”. $10 per square foot rebates were set for installation within a combined sewer system. $15 per square foot rebates were set for installation within a municipal storm sewer system. The greatest aspect of this incentivized project is the lack of restriction of building type that qualifies. There is no size cap on properties that qualify whether it’s residential, commercial or institutional. In 2016 there was a total of 2.3 million square feet of green roofing within the district. As of 2020, there is 5.1 million square feet of green roofing.

title: Green roof


text:
User:Greggygreggreg

Nice work on autonomous building - Welcome to the Wikipedia, hope you like it here. - &#35918&#30505

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: User:Greggygreggreg


text:
User talk:Greggygreggreg

Please look at green roof again. It has been 'wikified', meaning that it has been linked to many articles that already exist. I suspect it could be linked to a good deal more, e.g. evaporative cooling is likely already an article under some name. If not, perhaps it should be, as it's a technical term.

As such a green roof is often found on an autonomous building, and you have worked on that article too, I find it surprising you didn't link to that. Was that intentional? I didn't think so, as you included no internal-to-wikipedia links there at all.

Also is there any relation between a green roof and the arcology idea? For instance, is it part of arcology to make someone's roof someone else's patio? Certainly that *could* be done, and perhaps that potential should be mentioned.

Photos would be nice if you get around to it, but it's often hard to find ones that can be released under the GNU FDL.

Welcome, and I hope you keep adding stuff like this. We very badly need it!

title: User talk:Greggygreggreg


text:
Arthur Quiller-Couch

Sir Arthur Thomas Quiller-Couch (21 November 1863 – 12 May 1944) was a British writer who published using the pseudonym Q. Although a prolific novelist, he is remembered mainly for the monumental publication The Oxford Book of English Verse 1250–1900 (later extended to 1918) and for his literary criticism. He influenced many who never met him, including American writer Helene Hanff, author of 84, Charing Cross Road and its sequel, Q's Legacy. His Oxford Book of English Verse was a favourite of John Mortimer fictional character Horace Rumpole.

Life

Arthur Quiller-Couch was born in the town of Bodmin, Cornwall. He was the son of DrThomas Quiller Couch (d.1884), who was a noted physician, folklorist and historian who married Mary Ford and lived at 63, Fore Street, Bodmin, until his death in 1884. Thomas was the product of the union of two ancient local families, the Quiller family and the Couch family. Arthur was the third in a line of intellectuals from the Couch family. His grandfather, Jonathan Couch, was a naturalist, physician, historian, classicist, apothecary, and illustrator (particularly of fish). His younger sisters Florence Mabel and Lilian M. were also writers and folklorists.

Arthur Quiller-Couch had two children. His son, Bevil Brian Quiller-Couch, was a war hero and poet, whose romantic letters to his fiancée, the poet May Wedderburn Cannan, were published in Tears of War. Kenneth Grahame inscribed a first edition of his The Wind in the Willows to Arthur's daughter, Foy Felicia, attributing Quiller-Couch as the inspiration for the character Ratty.

Quiller-Couch was educated at Newton Abbot Proprietary College between the late 1870's and early 1880's. Thereafter, he also attending Clifton College, and Trinity College, Oxford, where he took a First in Classical Moderations (1884) and a Second in Greats (1886). From 1886, Quiller-Couch worked for a brief time as a Classics lecturer at Trinity. Thereafter, having gained some journalistic experience in London, mainly as a contributor to The Speaker (periodical), he resettled at Fowey in Cornwall during 1891.

In Cornwall he was an active political worker for the Liberal Party. He was knighted in 1910, and in 1928 was made a Bard of the Cornish cultural society Gorseth Kernow, adopting the Bardic name Marghak Cough ('Red Knight'). He was Commodore of the Royal Fowey Yacht Club from 1911 until his death. He was president of the Village Drama Society which was based at Kelly House in Devon.

Quiller-Couch died at home in May 1944, after being slightly injured by a jeep near his home in Cornwall in the preceding March during his daily walk to the Royal Fowey Yacht Club.

World War I
'''Duke of Cornwall's Light Infantry 10th Btn. (Cornwall Pioneers).'''

The 10th was an unusual battalion, having been raised in March 1915, not by the War Office, but by the Mayor and citizens of Truro. It initially had only two officers – Colonel Dudley Acland Mills who had retired from the Royal Engineers six years earlier, and Couch, who was devoid of any military experience. Neither of them was paid. Their work in raising and training a battalion for war was remarkable by any standard, but their Herculean efforts appear never to have been recognised by the military hierarchy. It must have been an enormous relief to these two gentlemen when the War Office took over the 10th Battalion on 24 August 1915.

Literary and academic career

In 1887, while he was attending Oxford, he published Dead Man's Rock, a romance in the style of Robert Louis Stevenson's Treasure Island, and later The Astonishing History of Troy Town (1888), a comic novel set in a fictionalised version of his home town of Fowey, and The Splendid Spur (1889). Quiller-Couch was well known for his story "The Rollcall of the Reef", based on the wreck of HMS Primrose during 1809 on the Cornish coast. He published during 1896 a series of critical articles, Adventures in Criticism, and in 1898 he published a completion of Robert Louis Stevenson's unfinished novel, St. Ives.

From his Oxford time he was known as a writer of excellent verse. With the exception of the parodies entitled Green Bays (1893), his poetical work is contained in Poems and Ballads (1896). In 1895 he published an anthology from the 16th- and 17th-century English lyricists, The Golden Pomp, followed in 1900 by the Oxford Book of English Verse, 1250–1900. Later editions of this extended the period of concern to 1918 and it remained the leading general anthology of English verse until Helen Gardner's New Oxford Book of English Verse appeared in 1972.

In 1910 he published The Sleeping Beauty and other Fairy Tales from the Old French. He was the author of a number of popular novels with Cornish settings (collected edition as 'Tales and Romances', 30 vols. 1928–29).

He was appointed King Edward VII Professor of English Literature at the University of Cambridge in 1912, and retained the chair for the rest of his life. Simultaneously he was elected to a Fellowship of Jesus College, which he also held until his death. His inaugural lectures as the professor of English literature were published as the book On the Art of Writing. His rooms were on staircase C, First Court, and known as the 'Q-bicle'. He supervised the beginnings of the English Faculty there — an academic diplomat in a fractious community. He is sometimes regarded as the epitome of the school of English literary criticism later modified by his pupil F. R. Leavis.

Alistair Cooke was a notable student of Quiller-Couch and Nick Clarke's semi-official biography of Cooke features Quiller-Couch prominently, noting that he was regarded by the Cambridge establishment as "rather eccentric" even by the university's standards.

Quiller-Couch was a noted literary critic, publishing editions of some of Shakespeare's plays (in the New Shakespeare, published by Cambridge University Press, with Dover Wilson) and several critical works, including Studies in Literature (1918) and On the Art of Reading (1920). He edited a companion to his verse anthology: The Oxford Book of English Prose, which was published in 1923. He left his autobiography, Memories and Opinions, unfinished; it was nevertheless published in 1945.

Legacy
His Book of English Verse is often quoted by John Mortimer's fictional character Horace Rumpole.

Castle Dor, a re-telling of the Tristan and Iseult myth in modern circumstances, was left unfinished at Quiller-Couch's death and was completed many years later by Daphne du Maurier. As she wrote in the Sunday Telegraph in April 1962, she began the job with considerable trepidation, at the request of Quiller-Couch's daughter and "in memory of happy evenings long ago when 'Q' was host at Sunday supper".

He features as a main character, played by Leo McKern, in the 1992 BBC television feature The Last Romantics. The story focuses on his relationship with his protégé, F. R. Leavis, and the students.

His Cambridge inaugural lecture series, published as On the Art of Writing, is the source of the popular writers' adage "murder your darlings": "If you here require a practical rule of me, I will present you with this: 'Whenever you feel an impulse to perpetrate a piece of exceptionally fine writing, obey it—whole-heartedly—and delete it before sending your manuscript to press. Murder your darlings.'"

Fiction

 * Dead Man's Rock (1887)
 * The Astonishing History of Troy Town (1888)
 * The Splendid Spur (1889)
 * The Blue Pavilions (1891)
 * The Delectable Duchy: Stories, Studies and Sketches (1893)
 * ''I Saw Three Ships and Other Winter's Tales (1893)
 * Wandering Heath: Stories, Studies, and Sketches (1895)
 * Ia, A Love Story (1896)
 * St Ives (1898), completing an unfinished novel by Robert Louis Stevenson.
 * Noughts and Crosses: Stories, Studies and Sketches (1898)
 * The Ship of Stars (1899)
 * A Fowey Garland (1899)
 * Old Fires and Profitable Ghosts (1900)
 * The Westcotes (1902)
 * The White Wolf and Other Fireside Tales (1902)
 * Hetty Wesley (1903) (This was based on the life of the poet Mehetabel Wesley Wright.)
 * The Adventures of Harry Revel (1903)
 * Fort Amity (1904)
 * The Shining Ferry (1905)
 * Shakespeare's Christmas and Other Stories (1905)
 * The Mayor of Troy (1906)
 * Sir John Constantine (1906)
 * Merry Garden and Other Stories (1907)
 * Poison Island (1907)
 * Major Vigoureaux (1907)
 * True Tilda (1909)
 * Corporal Sam and Other Stories (1910)
 * Lady Good-for-Nothing: A Man's Portrait of a Woman (1910)
 * Brother Copas (1911)
 * Hocken and Hunken: A Tale of Troy (1912)
 * My Best Book (1912)
 * News from the Duchy (1913)
 * Nicky-Nan, Reservist (1915)
 * Mortallone and Aunt Trinidad: Tales of the Spanish Main (1917)
 * Foe-Farrell: A Romance (1918)
 * Castle Dor (1962) This novel was left unfinished at his death, and completed by Daphne Du Maurier.

A collected edition of Q's fiction appeared as Tales and Romances (30 volumes, 1928–29).

Verse

 * Green Bays, Verses and Parodies (1893)
 * Poems and Ballads (1896)
 * The Vigil of Venus and Other Poems (1912)

Criticism and anthologies

 * The Golden Pomp, a procession of English lyrics from Surrey to Shirley (1895)
 * Adventures in Criticism (1896; 2nd edition, 1924)
 * Oxford Book of English Verse, 1250–1900 (1900)
 * From a Cornish Window (1906)
 * English Sonnets (Published in 1897, reprinted in 1910)
 * The Sleeping Beauty and other Fairy Tales from the Old French (1910)
 * The Oxford Book of Ballads (1911)
 * In Powder and Crinoline: Old Fairy Tales Retold (1913)
 * On the Art of Writing (1916)
 * Notes on Shakespeare's Workmanship (1917)
 * Studies in Literature: First Series, Studies in Literature: Second Series and Studies in Literature: Third Series (1918, 1922, 1929)
 * On the Art of Reading (1920)
 * The Oxford Book of Victorian Verse (1922)
 * Oxford Book of English Prose (1923)
 * The Poet As Citizen and Other papers (Macmillan, 1935)

Autobiography

 * Memories and Opinions (unfinished, published 1945)

title: Arthur Quiller-Couch


text:
Zaya Pandita

Zaya Pandita or Namkhaijamts (1599–1662) was a Buddhist missionary priest and scholar of Oirat origin who is the most prominent Oirat Buddhist scholar. Among his accomplishments is the invention of the Clear Script.

Biography
Zaya Pandita was the fifth son of Babakhan, a minor Khoshut prince. After Babakhan converted to Tibetan Buddhism in the early 17th century, he, like many other Oirat princes, wished for one of his sons to enter the Buddhist clergy. In pursuit of his wish, Babakhan chose Zaya to become a śrāmaṇera ("novice monk"). In 1615, Zaya journeyed to Lhasa where he would study and practice Buddhism, including study under the guidance of the Lobsang Chökyi Gyaltsen, 4th Panchen Lama.

In 1638, Zaya Pandita left Tibet at the direction of the Panchen Lama to conduct missionary work among the Mongols. One year later in 1640, he assisted Erdeni Batur, Khun Taiyishi of the Choros (Oirats) tribe, in assembling a pan-Mongol conference between the Oirat and the Khalkha Mongols. The purpose of the conference was to encourage the formation of a united Mongolian front against potential external enemies, such as the Kazakhs, Manchus, and Russians and to settle all internal matters peacefully. The conference produced a code, which provided protection from foreign aggression to both the Oirat and the Khalkha and guaranteed the free movement of people throughout Mongol land.

When not engaged in diplomacy between the Oirat and the Khalkha, Zaya Pandita spread Tibetan Buddhism to the Oirats, the Khalkha and even the Kalmyk people in far away Russia. In furtherance of his missionary work, Zaya Pandita composed a new alphabet, based on the traditional Mongolian alphabet, called "Clear script" (todo bichig) to transcribe the Oirat language as it is pronounced. By doing so, Zaya Pandita eliminated the ambiguities of the traditional Mongolian alphabet. From the time Zaya Pandita developed the Clear Script in 1648 until his death in 1662, he translated approximately 186 Buddhist texts from Tibetan language to the Oirat language while still serving the religious needs of the Oirat tribes in Dzungaria.

The todo bichig script is still used by Oirats in Xinjiang with slight revisions, and is taught alongside standard classical written Mongolian in that region.

title: Zaya Pandita


text:
Over-the-counter drug

Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid prescription. In many countries, OTC drugs are selected by a regulatory agency to ensure that they contain ingredients that are safe and effective when used without a physician's care. OTC drugs are usually regulated according to their active pharmaceutical ingredient (API) and strengths of final products.

The term over-the-counter (OTC) refers to a medication that can be purchased without a medical prescription. In contrast, prescription drugs require a prescription from a doctor or other health care professional and should only be used by the prescribed individual. Some drugs may be legally classified as over-the-counter (i.e. no prescription is required), but may only be dispensed by a pharmacist after an assessment of the patient's needs or the provision of patient education. Regulations detailing the establishments where drugs may be sold, who is authorized to dispense them, and whether a prescription is required vary considerably from country to country.

Usage
As of 2011, around a third of older adults in the U.S. reportedly used OTC drugs, and this number is increasing. By 2018, the prevalence of use by adults in the U.S. as first-line treatment for minor illnesses had reached 81%: however, there is some debate as to whether this figure relates to an actual improvement of health.

Canada
In Canada, there are four drug schedules:
 * Schedule 1: Requires a prescription for sale and is provided to the public by a licensed pharmacist.
 * Schedule 2: Does not require a prescription but requires an assessment by a pharmacist prior to sale. These drugs are kept in an area of the pharmacy where there is no public access and may also be referred to as "behind-the-counter" drugs.
 * Schedule 3: Does not require a prescription but must be kept in an area under the supervision of a pharmacist. These drugs are kept in an area of the retail outlet where self-selection is possible, but a pharmacist must be available to assist in the self-selection of medication if required.
 * Unscheduled: Does not require a prescription and may be sold in any retail outlet.

All medications other than Schedule 1 may be considered an OTC drug, as they do not require prescriptions for sale. While the National Association of Pharmacy Regulatory Authorities provides recommendations on the scheduling of drugs for sale in Canada, each province may determine its own scheduling. The drugs found in each schedule may vary from province to province.

India
In November 2016, India's Drug Consultative Committee announced it was embarking on establishing a definition of drugs which could be dispensed without a prescription. Prior to this, the general assumption was that any drug which did not fall into a prescription schedule could be purchased without a prescription. However, the needed definition had not been enacted by early 2018. The lack of a legal definition for OTC drugs has led to this US$4 billion market segment being effectively unregulated.

Netherlands
In the Netherlands, there are four categories:

 * UR (Uitsluitend Recept): prescription only
 * UA (Uitsluitend Apotheek): pharmacist only
 * UAD (Uitsluitend Apotheek of Drogist): pharmacist or drugstore only
 * AV (Algemene Verkoop): may be sold in general stores

A drug that is UA may be sold OTC but only by pharmacists. The drug can be on the shelves like any other product. Examples are domperidone, 400 mg ibuprofen up to 50 tablets and dextromethorphan. A drug that is UAD can also be sold at drugstores which are stores where no prescription can be filled. The drugs are usually on the shelves, and the store also sells items like toys, gadgets, perfumes and homeopathic products. The drugs in this category have limited risk and addiction potential. Examples are naproxen and diclofenac in small amounts, cinnarizine, 400 mg ibuprofen up to 20 tablets and also 500 mg paracetamol up to 50 tablets. Drugs in the AV category can be sold at supermarkets, gas stations, etc. and include only drugs with minimal risk to the public, like paracetamol up to 20 tablets, 200 mg ibuprofen up to 10 tablets, cetirizine and loperamide.

United States
In the United States, the manufacture and sale of OTC substances are regulated by the Food and Drug Administration. The FDA requires that all "new drugs" obtain a New Drug Application (NDA) before entering interstate commerce, but the act exempts any drugs generally recognized as safe and effective (GRAS/E). To deal with the vast number of OTC drugs that were already on the market before the requirement that all drugs obtain an NDA, the FDA created the OTC monograph system to review classes of drugs and to categorize them as GRAS/E after review by expert panels. Certain classes of OTC drugs would not be required to obtain an NDA and could remain on the market if they conformed to the monograph guidelines for doses, labeling, and warnings finalized in the Code of Federal Regulations

Thus, an OTC drug product is allowed to be marketed either (1) pursuant to an FDA monograph or (2) pursuant to an NDA for products that do not fit within a specific monograph. There is also the possibility that certain OTC drug products are marketed under the grandfathering provisions of the Federal Food, Drug, and Cosmetic Act, but the FDA has never formally acknowledged that any legitimate grandfathered OTC drug exists.

Examples of OTC substances approved in the United States are sunscreens, anti-microbial and anti-fungal products, external and internal analgesics such as lidocaine and aspirin, psoriasis and eczema topical treatments, anti-dandruff shampoos containing coal tar, and other topical products with a therapeutic effect.

The Federal Trade Commission regulates advertising of OTC products, in contrast to prescription drug advertising, which is regulated by the FDA.

The FDA requires OTC products to be labeled with an approved "Drug Facts" label to educate consumers about their medications. The labels comply to a standard format and are intended to be easy for typical consumers to understand. Drug Facts labels include information on the product's active ingredient(s), indications and purpose, safety warnings, directions for use, and inactive ingredients.

The 2020 Coronavirus Aid, Relief, and Economic Security Act (CARES Act) includes reforms that modernize the way certain OTC drugs are regulated in the United States. Many OTC monographs need to be updated but updating or changing an OTC monograph requires the slow and burdensome notice-and-comment rulemaking process. The CARES Act includes OTC monograph reform provisions that replace the rulemaking process with an administrative order process.

Restricted over-the-counter substances
An ill-defined third category of substances is products having over-the-counter status from the FDA while being simultaneously subject to other restrictions on sale. While they are legally classified as OTC drugs, they are typically stored behind the counter and are sold only in stores that are registered with their state. They may be unavailable in convenience and grocery stores that stock other non-restricted OTC medications.

For example, many drugstores have moved products containing pseudoephedrine, an OTC product, into locations where customers must ask a pharmacist for them. A prescription is not required; the change has been made in an effort to reduce methamphetamine production. Since the passage of the Illinois Methamphetamine Precursor Control Act and the subsequent federal Combat Methamphetamine Epidemic Act of 2005, the purchase of pseudoephedrine is restricted. Sellers of pseudoephedrine must obtain and record the identity of the purchaser and enforce quantity restrictions. After initial attempts to control methamphetamine use (by requiring documentation of sale with government issued ID as well as limits on the quantity an individual could purchase) failed to realize meaningful reductions in methamphetamine use and production, Mississippi passed House Bill 512 in the State Senate on February 2, 2010 "to require a prescription from a licensed medical professional to purchase over-the-counter medicines with pseudoephedrine, ephedrine, or any other precursor chemical that can readily and illicitly be converted into methamphetamine, methcathinone or any active/scheduled analogs of phenylethylamines/amphetamine." However, products containing the substance are still OTC in most states, since no prescription is required.

A similar regulation once applied to some forms of emergency contraception. However, on February 25, 2014, the FDA approved generic one-pill emergency contraception products for unrestricted sale on the shelf. There is no age limit or need for ID to purchase.

Furthermore, some Schedule V controlled substances may be classified as OTC products in certain states. Such drugs are sold without a prescription but are subject to record-keeping rules and quantity and/or age restrictions, and they must be dispensed by a pharmacy. Finally, pharmacies frequently require a prescription for Schedule V drugs as a matter of policy, despite their OTC status according to applicable laws and regulations.

United Kingdom
In the United Kingdom, medication is governed by the Medicines Regulations 2012. Medication falls into one of three categories:

 * 1) Prescription Only Medication (POM), which is legally available only with a valid prescription from a prescriber. A pharmacist has to be on the premises for POM medicines to be dispensed, required by law. The medicine has been specifically prescribed for the patient holding the prescription, so it is considered safe for only the recipient to take. Just a small example of these include most antibiotics and all antidepressants or antidiabetic medications. Certain POM medicines are additionally marked Controlled Drug (CD) due to risk of abuse and the possibility of diversion for sale as street drugs. Examples of CDs include all benzodiazepines and strong opioids such as heroin and fentanyl.
 * 2) General Sales List (GSL), available off the shelf with no pharmacy training required to sell (so they can be sold anywhere, such as supermarkets). In general, they are considered safe for most people when taken correctly. Examples of these include 16-packs (or less) of painkillers such as paracetamol, ibuprofen, and aspirin as well as a host of other medications such as small pack sizes of some antihistamines, some laxative medication, and skin creams. This also includes the recreational substances alcohol and caffeine (where they are included in medicinal products), and some nicotine preparations.
 * 3) Pharmacy Medicines (P) are medicines that are legally neither a POM or GSL medication. These can be sold from a registered pharmacy but should not be available for self-selection (although directions to discuss a 'P' product may be allocated shelf space with associated GSL items). 'P' medications are reserved from the GSL list as they are either associated with a need for advice on use, or used in conditions which may require referral to a medical prescriber. Suitably trained counter assistants may sell a 'P' medication under the supervision of a pharmacist and will ask questions to determine if the customer needs to be referred for a discussion with a pharmacist. Some 'POM' medicines are available for use in certain situations and doses as 'P' medicines.

If it is not appropriate to sell a 'P' medication – i.e. the condition is not suitable for self-management and requires referral to a medical prescriber – then a sale should not occur and the pharmacist has a legal and professional obligation to refer this on to an appropriate service.

Examples of these include some sleep aid tablets such as diphenhydramine, human deworming tablets such as mebendazole, painkillers with small amounts of codeine (up to 12.8 mg per tablet), and pseudoephedrine. Medication available only with a prescription is marked somewhere on the box/container with [POM]. Pharmacy-only products are marked with [P]. A prescription is not required for [P] medicines, and pharmacy sales assistants are required by Royal Pharmaceutical Society codes to ask certain questions, which varies for what the customer says. If they ask for a specific product, the pharmacy assistant must ask "Who is it for?", "How long have you had the symptoms?", "Are you allergic to any medication?", "Are you taking any medication?" ('WHAM' questions). If a customer asks for a remedy, e.g., hay fever, then the '2WHAM questions' must be asked "Who is it for?", "What are the symptoms?", "How long have you had the symptoms?", "Have you taken any action towards your symptoms?", and "Are you taking any other medication?". It is with this information that the pharmacist can halt the sale, if need be. No [POM], [P] or [GSL] products that are stocked in a pharmacy can be sold, dispensed, or pre-made until a responsible pharmacist is signed in and on the premises. Some medication available in supermarkets and petrol stations is sold only in smaller packet sizes. Often, larger packs will be marked as [P] and available only from a pharmacy. Frequently, customers buying larger-than-usual doses of [P] medicines (such as DXM, promethazine, codeine or Gee's Linctus) will be queried, due to the possibility of abuse.

Transitions between prescription and OTC
As a general rule, over-the-counter drugs have to be used primarily to treat a condition that does not require the direct supervision of a doctor and must be proven to be reasonably safe and well tolerated. OTC drugs are usually also required to have little or no abuse potential, although in some areas drugs such as codeine are available OTC (usually in strictly limited formulations or requiring paperwork or identification to be submitted during purchase).

Over time, often 3–6 years, drugs that prove themselves safe and appropriate as prescription medicines may be switched from prescription to OTC. An example of this is diphenhydramine (Benadryl), an anti-histamine which once required a prescription but now is available OTC nearly everywhere. More recent examples are cimetidine and loratadine in the United States, and ibuprofen in Australia.

It is somewhat unusual for an OTC drug to be withdrawn from the market as a result of safety concerns, rather than market forces, though it does happen occasionally. For example, phenylpropanolamine was removed from sale in the United States over concern regarding strokes in young women. A study has been done examining consumer's perceptions about the risk of and access to nonprescription medication. The study concluded that a small percentage of consumers prefer having access to medication over potential risks of taking non-prescribed medication. Ranitidine was suspended in multiple markets due to concerns over the presence of the carcinogen N-nitrosodimethylamine (NDMA).

In the United Kingdom, it was announced in February 2007 that Boots the Chemist would try over-the-counter sales of Viagra in stores in Manchester, England (previous available as prescription only). Men aged between 30 and 65 could buy four tablets after a consultation with a pharmacist.

title: Over-the-counter drug