Bringing a vision to life: a healthy, joyful home that fits perfectly [Part 2]

Nadia and Gavin Sole live in a certified Passive House home in Richmond, Christchurch built by Ethos homes. (Read Part 1 of their story)


Nadia had no doubt about the value of certifying their home. “Anyone can say, ‘built along Passive House lines’ but there’s a lot of room between that and actually delivering a certified Passive House.”

Nadia and Gavin pictured with their sons and the plaque for their certified Passive House home.

The certification process is carried out by an independent expert in two phases. First is the pre-construction review: as the name indicates, completed before work starts on site. During the design phase, a Passive House designer using software called PHPP which models how all the different components of the building work together. It’s quick and easy to change various parameters in a computer model compared to mid-way through construction!

This process ensures that the building’s performance will meet the stringent Passive House requirements, but also that money isn’t being wasted. Passive House aims for a sweet spot, where cost and complexity are weighed against outstanding energy efficiency, long-lasting structural integrity, outstanding indoor air quality and wonderfully comfortable temperatures all year around. “Passing the pre-construction review was good, we knew we were on track,” says Nadia. At this stage, before any work started on site, they could be sure about the quality and performance of their new home.

The second phase of Passive House certification includes testing the building’s performance at several stages of construction (air tightness and ventilation) and finally, a fine-tooth comb review of evidence and documentation to make sure the building was built as designed. Once completed, the homeowner can be confident they’ve got the home they paid for. And architects/designers and contractors get feedback from building physics that helps them keep learning and improving—plus the satisfaction of knowing they’ve done right by the client.

Part 1: The right builder | Part 2: Certification | Part 3: Healthy materials