As the name suggests, a semi-extensive roof falls somewhere in the middle of an intensive and extensive green roof in terms of depth and weight. It can support small home gardens, playgrounds, full-scale parks, and even vegetable gardens. Gardens and parks on roofs can store a great deal of water and are therefore good Sustainable Urban Drainage Systems (SUDS) for stormwater management. Green Roofs come in many different forms, specified to suit individual needs. While the benefits of green roofs aren’t widely recognized in North America yet, green roofs are popular in Europe. Maintenance is also important to consider when designing a green roof. The insulating properties of the soil can also help reduce sound transmission through the roof from outside the building. A green or cool roof can be installed with solar panels. Intensive green roofs weigh from 35 pounds to beyond 100 pounds per square foot when dry - it is all a matter of the soil depth, which is affected by the amount of mounding that is used. Rainwater is stored by the green roof substrate and then … 3. Green Roof Systems: Intensive, Semi-Intensive, and Extensive, Environmental Product Declarations (EPDs): A Guide for Architects, Fabrics and Textiles for Interiors and Furniture, Types of Roof Membranes for Flat or Low-Slope Roofs, Intumescent Paint, Fireproofing, and Firestopping, Through Penetration Firestop and Fire Resistive Joint Systems, sedum, moss, grass, herbs, flowers, shrubs. By using an ANS GrufeKit system as the base of your semi-intensive green roof you will benefit from a strong and flexible roof covering that can be self-installed with its simple clip together modules. With growing deforestation and urban expansion there are less plants naturally available to absorb the growing emissions of carbon dioxide. Green roofs can help reduce stormwater run-off, mitigate the urban heat island effect and clean the air, benefits that accrue to the community. Brown Roof: This type of intensive roof is a perfect example of the community benefit a commercial green roof can provide. Reduces runoff and improves water quality. Benefits of Green Roofs A few of the many benefits to green roofs are listed below. They might be preferential for roofs that have too much of a slope for an intensive version, but where you’d like more variety and environmental benefits than you might get with an extensive green roof. Heat islands are created by buildings and pavement that absorb sunlight during the day and release the energy as heat in the evening. EXTENSIVE GREEN ROOFS Extensive green roofs provide a light-weight, low maintenance, instant ‘green effect’ roof solution, and are the most common type of green roof we supply. Since the plants sit on top of the roofing materials they act as a barrier, protecting the roof from direct ultra–violet radiation, wind, hail and extreme temperatures. This is especially true of intensive green roofs, which can have soil that is two feet deep or more. commercial and public buildings include: • Improved water quality due to reduced stormwater runoff and fewer overflows of combined sanitary However, intensive roofs also have greater potential for ecological benefit and amenity use than extensive roofs. Green roofs can help reduce energy costs for a building by acting as another layer of insulation between the inside and outside of the roof. A green roof acts as a superinsulator, enabling the home to hold in more heat during the winter and keep out the heat during the summer. This potentially lessens the need for complex and expensive drainage systems and reduces the amount of pollution in our rivers, lakes, and oceans. If the roof is occupied, additional maintenance should be accounted for to make sure the roof is safe and comfortable. As you invest in your home, make a long term investment in a green roof. The owner should understand that a green roof requires routine landscape maintenance, which can vary from occasional to regular and can add a significant ongoing cost. Urban agriculture on green roofs would be considered an intensive green roof, as they need regular maintenance, relatively deep soils and a certain amount of irrigation. Garden Roof® Assembly: Intensive - The landscape possibilities with an Intensive Garden Roof® Assembly are virtually limitless. Intensive green roofs offer a great potential for design and biodiversity. Extensive – Roofs that are covered by hearty native ground cover such as grass, thyme, and sedums. They have been shown to reduce cooling costs for buildings by as much as 25%. 1. The Urban Heat Island Effect The greater insulation offered by green roofs can reduce the amount of energy needed to moderate the temperature of a building, as roofs are the site of the greatest heat loss in the winter and the hottest temperatures in the summer. For instance, it may be inconvenient to take a lawnmower to the roof on a weekly basis if there is an area of grass that requires regular trimming. With rising energy costs and the threat of climate change, many people are choosing to utilize green roof designs for their homes. It is important that all local codes and standards are adhered to. A typical growing medium depth of an intensive green roof is 6 inches or more. If the air on the roof is made cooler by a green roof, this process is easier and uses less energy. Extensive – Roofs that are covered by hearty native ground cover such as grass, thyme, and sedums. All rights reserved. But, as you can imagine, having a garden on your roof also brings its downsides. Green roofs can provide much needed vegetation in urban areas that need it the most. Archtoolbox is a Trademark of Aggregate Digital LLC. Any water that is released is done so at a slower and more consistent rate, which helps prevent flooding and runoff that can be destructive to the surrounding environment. The biggest benefit of extensive green roofs is that they need very little maintenance. They require complex structural support and irrigation. Please consult a professional architect, engineer, consultant, or agency for advice about specific projects, buildings, conditions, codes, and/or regulations. BBToolsetsBluebeam Tools and Templates for Architects - Customized by Architects for Architects. Green roofs are also attractive, and some can be very low-maintenance, extending the lifespan of the roof itself. Regular Roof Green Roof Expand roof life 2x3 times (up to 60 years) In addition, to the benefits of removing pollutants, green roofs can also provide climate change mitigation through managing temperature. A more traditional planted roof of built-up layers is also common, but the tray system offers much more flexibility and comes pre-planted with mature specimens. Best Architecture BooksOur list of the top reference books for architects - these are the ones we have on our shelf. The soil is usually not more than 5" deep and is sometimes contained by a tray system, which provides a barrier to excessive growth, protects the roof membrane, and also interlocks the entire system together to prevent wind damage. For example, research published by the National Research Council of … Beauty Green roofs can make your property more attractive. The wide variety of benefits include environmental, economic and even social advantages. Being low maintenance, cost effective and eco friendly, green roofs are a great selling point, especially in urban areas where green space is limited. Semi-intensive green roofs require a deeper soil layer, but the payoff is in the types of plantings that can be used. Another term for these green roofs is “rooftop garden.” Compared to traditional roofs, green roofs can cut down building electricity consumption by 2%–6% especially for summer cooling by maintaining temperature. One important item to design for is an increased structural load. In the winter time a green roof acts as insulation, keeping more heat in than a standard roof. Many plants will benefit greatly from an irrigation system especially if non-native vegetation is selected for its aesthetics. A properly designed and installed extensive green-roof system can cost $108–$248/m 2 ($10–$23/sq ft) while an intensive green roof costs $355–$2,368/m 2 ($33–$220/sq ft) 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. Before getting into the benefits of a green roof, let’s talk about the types of green roofs you might consider. It’s very large and planted more deeply, and it provides a nesting habitat for birds, as well as energy and water management benefits. But this rooftop garden type also requires intensive care, with regular professional maintenance and advanced irrigation systems. The structural engineer must factor in the weight of completely saturated soil since the plantings and the soil will hold a significant amount of water. Installing a green roof can cost up to twice as much as installing a conventional roof. That’s one less thing to worry about cleaning and maintaining around the house. The plants, if chosen correctly for the climate, rarely need water so an irrigation system is not required. We also provide the benefits and a few things to watch out for when designing green roofs. Tray systems are not a viable option for intensive roofs due to the weight; therefor, a significant amount of attention must be paid to the various waterproofing and root barrier details. A green roof may include components of these two types of green roof systems and be referred to as either semi-intensive or semi-extensive green roof. This article provides an general overview of green roofs installed on buildings. If so, share your experience in the comments below! When it comes to installation, there are two main types of Green Roofs to choose from. Ready to design a new home, or renovate an existing home? Green roofs tend to improve the life of the membrane because it is completely covered by plantings and isn't exposed to the sun's harsh UV rays. In addition to the mosses, grasses, and sedum of extensive roofs, semi-intensive plantings include herbs, flowering plants, taller grasses, and small shrubs. Green roofs can help reduce energy costs for a building by acting as another layer of insulation between the inside and outside of the roof. This system supports everything from small personal/home gardens to full scale public parks. Data collected from a study by researchers at the Pennsylvania State University, Center for Green Roof Research shows that green roofs captured almost 60% more rainwater than a standard roof. Although green roofing systems come with several inconveniences, their pros far outweigh their cons. To reap green roof benefits, you need to choose which type of green roof you want to install. We also earn commissions from qualifying purchases at This type of green roof is the best for homes and small buildings since they are lightweight, have less startup costs, and are much easier to maintain than the intensive green roofs, Semi-Intensive – Combination of semi-intensive and extensive roof types. This deeper soil allows intensive roofs to accommodate large plants and dramatic plant groupings. An extensive green roof generally costs between $10 to $24 per square foot. Scientists at Michigan State University found that replacing traditional roofing materials with green roofs in an urban area the size of Detroit, with a population of about one million, would capture more than 55,000 tons of carbon. Extensive roofs are also the cheapest to install and maintain. #2 Green roofs reduce stormwater runoff. The intensive green roof uses planting mediums that have greater depth than the extensive green roof. There are a number of things to consider when designing for a green roof. Intensive Green Roof Systems – The Advantages. You can choose from the three main types of green roofs: Intensive Roofs: An intensive roof often functions as a rooftop park or a community garden. We will provide a description of the three main types of green roofs: intensive, semi-intensive, and extensive. They are typically constructed in layers, but can also be installed using a tray system. When the temperature of the roof is reduced, so is the temperature of the building interior. Intended for recreational, sporting and leisure purposes, they are often indistinguishable from at-grade landscapes. Learn more by reading through the advantages and disadvantages of green roofs: Advantages . That is roughly similar to eliminating a year’s worth of carbon dioxide emitted by 10,000 midsize SUVs and trucks. Intensive Roofs are thicker and have a minimum depth of 12.8cm (5 1 ⁄ 16 in). Help make Archtoolbox better for everyone. They are expensive, and more intensive green roof… The phenomenon leads to zones of higher temperatures around urban areas. A green roof is one that is covered – either partially or completely – with vegetation. Extensive green roofs are generally made up of a very thin layer of soil or other planting medium with shallow-root plants like sedum, mosses, and grasses. Intensive green roofs and roof gardens. In the summertime the vegetation on the roof absorbs the light and heat from the sun, keeping the roof cool. The benefits of green roofs With continued urban expansion absorbing the habitats of our indigenous plants, insect and birds, living roofs can provide fresh areas for the local ecology to thrive. Furthermore, the water that does run off a green roof is filtered through the vegetation, so it is much cleaner. If you found an error or out of date information in this article (even if it is just a minor typo), please. However, maintenance requirements are generally no more than would be expected for sidewalk planters. Green roof temperatures can be 30–40°F lower than those of conventional roofs and can reduce city-wide ambient temperatures by up to 5°F. Many people are ‘going green’ in the hopes of reducing their own carbon footprint and lowering their energy costs. Intensive – These roof types can support trees, shrubs, and even benches. It is important that a protective barrier be used over the waterproofing membrane. Combining a green roof and solar panels may actually benefit both installations by providing shade for the green roof plants, and lower temperatures for the solar panels which can boost efficiency. Furthermore, these modules also make maintenance such as finding roof leaks, or moving sections of roof very easy. Intensive green roofs, with increased layers and ability to retain large amounts of water, make this consideration especially important. You will find that there are so many benefits of green roofs, which will make your home perfect, and we will tell you some of the problems that can be solved by green roofs. However, the membrane may be exposed to plant roots, animals and insects, and fertilizer chemicals. Cooler roof temperatures produced by a green roof help boost the efficiency of rooftop mechanical equipment by making the air on the roof cooler. Heat islands, especially in urban areas, negatively affect microclimates by raising temperatures and altering air movement patterns. Of course, this comes with a steeper price tag due to the additional weight and root barriers needed. Green Roofs for Urban Businesses – Building Success and Healthy Cities Across the Globe, would capture more than 55,000 tons of carbon. Green roofs have numerous benefits for the user. Green roofs actually offer many advantages and could offer many environmental benefits. Do you own an eco-friendly roof? When in cooling mode, HVAC equipment must pre–cool outside air to get it to the required temperature. The soils of a green roof will capture a significant amount of stormwater, which is absorbed and used by the planted material. 2. It is also important to factor in the type and lifetime of the roof membrane that will be used. Intensive green roofs typically cost twice as much to install as extensive green roofs because of their thicker, more complex assembly. Although intensive green roofs are, on the whole designed for people they can provide important ‘garden’ habitat in our towns and cities. This leads to lower ambient temperatures in the microclimate surrounding buildings. Improve property values and marketability. What is an Intensive Green Roof? Bauder has experience in helping design accessible roofs and roof gardens to achieve the right layout and planting choices. As an Amazon Associate, Archtoolbox earns from qualifying purchases. The plants and soils also filter the stormwater, which helps clean it of pollutants that can negatively affect the natural surroundings. Consider a green room in your design and achieve a return on your investment through energy savings and extended roof life. Extensive systems weigh anywhere from 10 to 25 pounds per square foot when dry, which is why the interlocking system of trays is important - otherwise, strong winds could very easily blow the plantings away. Intensive – These roof types can support trees, shrubs, and even benches. Display and/or use of the information contained within this site constitutes acceptance of the Terms of Service and Privacy Policy. In addition, space should be allocated for storage of maintenance materials. Extensive green roofs are not usually intended for general public access, and are chosen mostly for their ecological benefits. Many jurisdictions now require building owners to collect stormwater in infiltration basins that clean and slowly release the water back into the ground to help reduce the burden on the sewer systems - green roofs help do this naturally without the need for special infiltration basins or equipment. All that is really needed is an occasional inspection to confirm that the trays are intact and that the plants are flourishing. Semi-intensive systems generally weigh between 25 and 40 pounds per square foot when dry. You’ll also help to slow climate change, reduce the amount of stormwater runoff and improve the water quality of rivers, lakes and streams. They require complex structural support and irrigation. They also help manage stormwater runoff in areas with a lot of rainfall and can improve air quality when installed in urban environments or on large, city-wide scales. However, the setup costs for a green roof are high. An intensive green roof offers a great potential for highly creative designs and biodiversity. By planting as such native vegetation as possible, whether herbaceous, shrubs or trees. Fertilizers are also not required except in rare instances where weeds need to be controlled. How to Set Up Your Website PortfolioA free guide to hosting your own website potfolio. According to the National Park Service, over its estimated lifespan of 40 years a green roof would save about $200,000, of which, nearly two–thirds would come from reduced energy costs. Intensive roofs are usually occupied so special attention needs to be paid to walkways and other occupied zones so that visitor safety is maintained. Intensive green roofs use a variety of plant species, which may include trees and shrubs. The natural plantings and soils in green roofs mitigate the heat island effect by better modulating temperature fluctuations caused by radiant heating during the day. Therefore, lower air temperatures on the roof improve the efficiency of heat–rejecting rooftop HVAC equipment because it is operating at a lower ambient temper… Intensive green roofs require the deepest soil and have the greatest impact on the structural design, but they also accommodate all types of plantings including large shrubs and trees. Environmental benefits – Improves air quality and reduces the Urban Heat Island Effect, keeping air temperature cooler than a traditional rooftop would . The environmental benefits of installing green roofs on . This is most noticeable in intensive green roofs since there is a thicker and more consistent layer of soil, which provides a higher insulating value. Apart from the effective intensive green roof weight, depth and thickness, there are also a number of benefits that apply to the overall green roof concept. Whilst intensive green roofs are more formal spaces they can provide inherent benefit for biodiversity. We have attempted to address this by using high albedo (light colored) materials, but this simply reflects the radiant heat to other materials that can absorb it an release it in the evenings. There are three types of green roofs. Plant selection and design greatly affects the maintenance required for the upkeep of these roofs. This website uses cookies. What problems do green roofs solve? The two kinds of green roofs: intensive and extensive. This is most noticeable in intensive green roofs since there is a thicker and more consistent layer of soil, which provides a higher insulating value. We make sure they remain successful landscapes for years to come. Intensive green roofs tend to be areas where greater access and people traffic is envisaged. Copyright © 2020 Archtoolbox. This is especially important where building occupants overlook lower roof areas, which are often barren planes or are full of mechanical equipment. Whether you opt for an extensive, semi-intensive or an intensive green roof, you are bound to reap its many benefits. In some cases a green roof can also eliminate the need for rain gutters. A cross section of the system layers is below: Intensive green roofs offer considerable benefits to the urban landscape far and above anything a light sedum roof can offer. Larger plants will also require regular pruning and will have to be monitored for health. Landscaping flat roofs offers an effective and practical use of space, … Perhaps the most important benefit of green roofs is that they can reduce the amount of and improve the quality of stormwater runoff from a building site. Green roofs not only reduce the amount of energy your home uses, but they also have a wide variety of ecological benefits. GREEN ROOF COSTS AND BENEFITS. Intensive green roofs incorporate all these advantages as … Plants for Green Roofs Semi-intensive green roofs require a bit more maintenance since the plants tend to need pruning, irrigation, and fertilization. One benefit of green roofs that is not easily quantifiable is the aesthetic improvement that landscape provides. Simply providing planted areas on these low roofs will improve the appearance of the space, which may improve occupant mood and well-being. However, this depth also means that an intensive green roof adds a lot of weight to a building, which your architect or structural engineer will need to account for.