The study looked at a range of benefits of green roofs including stormwater management improved health benefits due to reduced pollution and energy savings.
Green roof savings.
Green roofs reduce the heat flux through the roof and less energy for cooling or heating can lead to significant cost savings.
Shading the outer surface of the building envelope has been shown to be more effective than internal insulation.
Many studies have been conducted to assess the extent of energy savings possible with extensive green roofs.
The exact amount of savings is difficult to calculate as utility costs vary from state to state.
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.
Many studies have been conducted over the past 10 years to consider the potential building energy benefits of green roofs and shown that they can offer benefits in winter heating reduction as well as summer cooling.
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.
There are many different reported benefits that the addition of a green roof to a building can offer.