Casa Aguila, a 4-bedroom home in Ramona, CA, was custom-built for homeowners looking to be grid-independent in the future. Designed and constructed by Alliance Green Builders to stringent California Title 24 Standards, the project includes numerous resource-saving highlights.
In a state where water is a scarce resource, Casa Aguila was built with water conservation in mind. One of their biggest hurdles was obtaining a blackwater permit in a County not known to be open to new ideas. While these systems typically use very complex machinery, the Casa Aguila design was much simpler and was created with a built-in backup system that utilized the existing septic tank and leach field. With the help of the project consultant, Bill Wilson, they were able to categorize the system as an “advanced wastewater treatment system”, allowing the home to become the first residential project in San Diego to obtain a blackwater treatment permit.
“If we had been going for a greywater permit alone, it would have probably been a pretty simple process. However, acquiring the greywater/blackwater permit was challenging,” says Katie Teare of Alliance Green Builders.
The home also employs four 10,000-gallon rainwater cisterns for potable water, four 10,000-gallon stormwater tanks for irrigation of ornamental landscaping, and one 10,000-gallon greywater tank that is specifically used for irrigation and fire suppression.
“The greywater and blackwater from the home are combined and flow through two consecutive tanks,” says Teare. “First the existing tank septic and then the new tank - and are filtered and distributed through irrigation lines to a permaculture Food Forest.”
As far as energy savings go, this home boasts 22.1-kW of PV, a 3.2-kW wind turbine, and backup battery storage, giving it a -92 CA Energy Design Rating (EDR). For comparison, a new home that is built and verified to meet the bare minimum Title 24 requirements is considered to have a Title 24 score of 0%.
Alliance Green Builders’ success on this project will allow the greywater/blackwater design to be used as a blueprint for others who would like to undertake similar projects and provide clients with the highest level of resource conservation and energy efficiency in California.
Interested in learning more about water efficiency in the construction process? Learn more about the EEBA Water Efficiency for Builders and Designers seminar.