Benchmark Home Size: Determine Path by Bedrooms and Conditioned Floor Area

DOE Zero Energy Ready Home (Revision 07) offers a prescriptive path and a performance path to meet the program requirements. Builders whose homes meet the home size eligibility requirement may choose either the prescriptive path or the performance path to qualify a home to the program requirements. Builders who don’t meet the size requirement must use the performance path.

The prescriptive path provides a single set of measures that builders must follow to construct a DOE Zero Energy Ready-labeled home based on the requirements listed in the DOE Zero Energy Ready Home Exhibits 1 and 2. The performance path requires builders to determine a target Home Energy Rating System (HERS) Index score by modelling a target home based on the builder’s design and using the energy-efficiency features listed in Exhibits 1 and 2; the performance path allows the builder to make tradeoffs to meet the HERS target index. 

To assess eligibility, the builder determines the number of bedrooms in the home to be built and compares that to the conditioned floor area of a “benchmark home” as shown in Exhibit 3. If the conditioned floor area of the home to be built exceeds the value shown in Exhibit 3 for the number of bedrooms, the performance path must be used.

Exhibit 3: Benchmark Home Size

For example, if a builder plans to build a 3-bedroom house that is 2,000 sq. ft., his home size will be lower than the benchmark home limit for a 3-bedroom home of 2,200 sq. ft. so the builder can use either the prescriptive or the performance path. However, if the builder plans to build a 3-bedroom house that is 2,500 sq. ft., he will have to use the performance path. For homes with more than 8 bedrooms, the CFA Benchmark Home shall be determined by multiplying 600 sq. ft. times the total number of bedrooms and adding 400 sq. ft.

For example, for a 10-bedroom home (600 sq. ft. x 10) + 400 sq. ft. = 6,400 sq. ft.