Shawna Henderson and Hal Richman have worked in the NZE arena for several years, through BHE sister company Bfreehomes Design Ltd. Bfreehomes offers NZE and Deep Energy Retrofit design and consulting services to homeowners, and carries out applied research with large organizations such as Natural Resources Canada (NRCan) and Canada Mortgage and Housing Corporation (CMHC).
Between 2009 and 2011, Bfreehomes conducted surveys and builder focus groups in seven distinct markets for NRCan to develop and fine-tune ways to analyse the cost of achieving whole house energy reduction targets leading to NZE. Bfreehomes also reported on the field study results and produced a training presentation for R-2000 builders with case studies. A version of that presentation can be seen here.
With no change to construction practises, current trade skills or commercially available products or systems, a builder
can achieve 25% energy efficiency with a marginal cost increase of about 3% (about $10K), and up to 50% energy
efficiency with a marginal cost increase of about 6% (about $18K). To achieve energy efficiency levels of 75%, a
renewable energy contribution is required (10 to 15 GJ/year). For a 75% target, the marginal cost is 14% (about
$35K). To achieve net-zero energy performance, integration of energy efficiency and renewable energy sources
becomes critical (about $110K).