Extensive Green Roof Energy Savings

Energy performance is a key benefit of green roofs.

Extensive green roof energy savings.

There are many different reported benefits that the addition of a green roof to a building can offer. 8 to 20 per square foot. Many studies have been conducted to assess the extent of energy savings possible with extensive green roofs. Green roofs are energy efficient.

In summer the green roof protects the building from direct. Both extensive green roof cubicles 24 show less energy consumption 16 7 and 2 2 respectively than the reference one 25 during warm periods whereas both extensive green roof systems present a higher energy 26 consumption 6 1 and 11 1 respectively compared to the reference cubicle during 27 heating periods. The breathable layer growing media on a green roof is also the basis for the well being of the plants and must be able to store water and air at the same time for a healthy growth. The green roof market is dominated by extensive designs with shallow growing mediums and deciduous plants that offer little potential for winter energy conservation.

Whilst green roofs are important for cooling cities as a whole a green roof can roof can also have a positive impact on the energy balance within any given building this is particularly relevant if a building has poor insulation and poor ventilation. Shading the outer surface of the building envelope has been shown to be more effective than internal insulation. A 2006 study by the university of michigan comparing costs of conventional and green roofs showed that on average installing a green roof costs about 22 00 sq. There is only one difference.

Green roofs reduce the heat flux through the roof and less energy for cooling or heating can lead to significant cost savings. Green roofs are often compared to white roofs which are only used to reduce the amount of heat entering a building or to reduce the urban heat island in the summer 3. 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. 1 2 in addition green roofs can reduce building energy use by 0 7 compared to conventional roofs reducing peak electricity demand and leading to an annual savings of 0 23 per square foot of the roof.

The energy saving potential wh m 2 is calculated by dividing the difference of cooling energy between the respective reference model and the model with an extensive green roof added by the. 15 to 50 per square foot. The green roof growing media green roof soil is the breathable layer. For a conventional roof.