Originally Posted by
Super_BQ
Again, I feel like i'm repeating and while my past post has been lengthy, the real issue has nothing to do with how crappy the NZ building code is. The reason is, "Is it warranted for NZ to transform from a passive building design approach to an ACTIVE building design approach that has become the standard in most OECD places???"
I was born and raised in Canada for most of my life. Have many friends in the building industry there and it's very clear, NZ climate is nothing like Canada. The population of NZ does not experience -40C and +40C every year. When I was attending Uni in Canada, the common complaint I heard from overseas Asian students was the winters and summers were TOO DRY for their precious facial skin. Anyways, just saying the climate is different and has nothing to do with how much insulation houses have. It's ALL to do with the management of indoor ventilation and heating / cooling ; albeit actively or passively.
IMO, I do not believe NZ is ready to pay the higher cost to go the active design approach. You have an HVAC system that would add an easy extra $50K, then you have to pay probably another $50K to air tight the house. Then you have the higher running cost of these systems. If you look on Google, the carbon foot print of going active ventilation is considerably higher than houses that rely on passive ventilation. NZ's climate quite simply is not that extreme to warrant it. What I see is the media and people are quick to criticize NZ's poor home comfort, but don't understand the impact of the NZ RMA. If we go on a path like they do overseas, then definitely the RMA would have to be changed. But people in NZ enjoy windows that face the sun, 'these passive design approaches' and it explains why streets are not grided in NZ. Because when you go passive design, EACH AND EVERY house can be positioned to face the sun to maximise solar gain. In an active design house, you don't have to care how the house faces the sun (as the heating source from the sun is secondary), and you can build the house very close to each other, and the streets can be gridded for more efficient vehicle traffic flow, concepts like back alleys etc. all come into play when when the houses built don't have to rely on sun orientation. But again, energy costs in NZ are way too high to make these systems affordable. I mean you can say single glazed windows are horrible but really.. what is worse? A highly insulated, sealed air tight house with no mechanical ventilation? or a house with triple glazing but is drafty all over? The 2 building systems are world's apart different. We can't be advising NZ building code to go ie. triple glazing, high R value insulation, WITHOUT ADDRESSING the management of indoor air quality. Everyone that believes they're building a custom home in NZ of higher standard is building nothing different than minimum standard because the single factor that all seem to over look is the installation of mechanical ventilation and / or balanced flow HRVs.