Green Roof Runoff Calculator

Conventional development site conditions including roof size parking lot area and street sidewalk and driveway area.

Green roof runoff calculator.

Simulations are available for new construction ashrae 90 1 2004 and old construction pre ashrae 90 1 2004 office and residential buildings driven by typical precipitation and. Green infrastructure bmp options. To help further promote green roof projects in the united states we decided to make our water runoff calculator tool available free of charge. Note that there was very little if any runoff during the may 1 to sept 30 growing season.

Figure 2 shows the daily rain and associated daily green roof runoff for 1993 in state college pa for a green roof having a maximum of 1 6 inches of water retention storage. For sample purposes a 55 gallon barrel will be used. The excel based spreadsheet is available for download from the downloads and calculators page of the green roof blocks website. They are commonly used on individual home lots to capture roof runoff.

When these results were averaged over the 28 year simulation period a 3 5 inch. Green roofs also known as vegetated roofs. Also outlined are the steps to build your own rain barrel to collect water from your roof and downspout for all outdoor uses like watering and cleaning. The green roof energy calculator is an online tool that allows users to compare the annual energy performance of a building with a vegetative green roof to the same building with either a dark roof or a white roof.

The system outlined below will walk you through the steps of determining your rain barrel sizes based on average roof runoff.