Site: The perfect site for an Energy Efficient Home is South – North facing (with living areas being to the north) and shelter from the East and West. These types of sites are very popular and either go very quickly or are more expensive.
Design: Compared to a stock standard NZ Building Code home, Energy Efficient and Passive designs require a higher level of attention to detail. Because of this, the drafting of Energy Efficient/ Passive House plans takes longer and therefore the cost of plans increase. We charge $140ph as a base rate for our design fees – however, if you choose to build with us, we will reduce the design fees to our cost price of $75ph. You can expect energy efficient plans to take an average of 70-90 hours (keep in mind – every design has it’s own challenges).
Build: the build time of an Energy Efficient Home takes longer than a standard build by about 1-2 months as far more care and detail goes into the build and installation of products. The build is where 85% of Passive Houses fail so we need to take our time during this phase to ensure everything is installed correctly and to a high standard – due to this increase in build time, the build cost goes up.
- Additional insulation – to insulate your walls, floor and ceiling you can expect to pay double overall compared to a standard build.
- Upgraded windows – triple glazed uPVC windows with Low-E coatings and argon gas are approximately 2x the amount of standard double glazed aluminium.
- Mechanical ventilation – the cost of these differ depending on brand and function. On average a Mechanical Ventilation system will cost you approximately $10- 15k plus install
- Air tight wrap – the ProClima system comes in at approximately $10 -15k plus install.
We suggest allowing $2400 per m2 to build an Energy Efficient Home.
All of the prices given are a rough estimate based on a single story, passive shaped (square floor plan), 4 bedroom home as of June 2021.