Snow Load

All of our OTechnology roofs can be engineered to accommodate heavy snow loads and/or roof gardens. We can also handle special requests for higher loads. Curved roofs are built to manage the extra snow load.  Snow loads vary across climate changes, depending mostly on where you live. Many factors affect snow load including whether structures are subject to drifts, the moisture content of the snow, and seasonal accumulation. If we’re talking about a roof, then how well it is insulated will affect how much snow melts and reduces load as a result.  Our structural engineers will inspect your climate or look at the needs for your roof garden and do the analysis.

Environmental Benefits

Vegetation, primarily forests, has been identified as an important component of any strategy to reduce greenhouse gas emissions, through the sequestration of carbon in the woody biomass of trees. Given the limited space available for additional trees in many metropolitan cities, new adaptation strategies such as placing the vegetation directly on building roofs (rooftop gardens) becomes especially attractive. Adding a rooftop garden to your OHome, OClass, or OHousing can help lower greenhouse gas emissions in our atmosphere.

Health and / or Social Benefits

Rooftop gardens offer many benefits to an urban area. They can reduce energy demand on space conditioning, and greenhouse gas emissions through direct shading of the roof, evapotranspiration and improved insulation values. If widely adopted, rooftop gardens could reduce the urban heat island, which would decrease smog episodes and problems associated with heat stress, as well as lowering energy consumption. Rooftop gardens can also improve storm water management by holding water in the soil until plants absorb it or it evaporates into the atmosphere. In this way, rooftop gardens delay run-off into the sewage system, thus helping to reduce the frequency of combined sewage overflow events, which is a significant problem for many major cities in North America. The plants and the growing medium can also filter out airborne pollutants washed off in the rain, thus improving the quality of the run-off. All of these benefits help improve the health of the people and the community using garden roof technology.

Economic Benefits

Heat flow through the building envelope creates energy demand for space conditioning in a building. Research results done by the National Research Council of Canada on energy efficiency and environmental benefits of rooftop gardens showed that the rooftop garden significantly outperformed the reference roof in spring and summer. The average daily energy demand for space conditioning in the case of the reference roof was 6.0-7.5 kilowatt-hours (20,500-25,600 BTU). However, the growing medium and the plants modified the heat flow and reduced the average daily energy demand to less than 1.5 kilowatt-hours (5,100 BTU)—a reduction of more than 75%. This can help save money annually by lowering your electricity needs. In addition, rooftop gardens can provide additional green space in your home and increase property values.

Snow Accumulation on Roofs: When to Worry
Making Houses Work Website