This section summarizes the net-zero measures.
Sources: AWWA Research Foundation 2000 Residential / Commercial and Institutional End Uses of Water. Lancaster B. 2006, Rainwater Harvesting for Drylands - Volume 1, Appendix 3. Net-zero measures can be applied to the building to optimize its interaction with the environment and reduce the net utility water usage to zero. Net-Zero water calculations are based on the cited literature.
Rainwater Harvesting -- In the rainwater harvesting calculation, default 'Annual Rainfall' is based on 30-year climate normal average precipitation data from the National Climactic Data Center, Climatography of the U.S. No. 81: Monthly Station Normals. The user has the option to compare rainfall data from other sources to the default value and modify 'Annual Rainfall' as appropriate. The catchment can be any area designed to collect and divert rainwater to a cistern. The 'Catchment Area' default provided is the total roof area of the building determined by the model, and it can be modified and saved by the user. Harvested rainwater will be applied to reduce the net utility demand for indoor water usage.
Native Vegetation Landscaping -- Savings for reduced irrigation as specified in the 2000 AWWA Research Foundation studies are applied for native vegetation landscaping to reduce the outdoor water usage.
Greywater Reclamation -- Savings resulting from access to a non-utility water source as specified in 2000 AWWA Research Foundation studies are applied for greywater reclamation to lower net utility demand for outdoor water usage.
Potable Water Sources -- If potable water sources, such as wells or streams, will be accessed on the site, specify the water yield from these sources and they will be applied to reduce the net utility demand for indoor water usage.