Energy efficiency has been the main feature of building code regulation changes. The Ministry of Business, Innovations and Employment’s (MBIE) new regulations come into effect in May 2023.

All new building work in homes - including additions and alterations as well as new builds are affected. The measures see increased insulation needed for underfloor, walls, roofs, and windows.

 For residential buildings the energy savings to heat a house will be reduced by 40% on the previous standard. For commercial buildings the figure is 23% compared to the previous standard.

By November 2023 windows in new houses will be required to meet the new increased performance levels throughout the country. Double 
glazing alone is no longer sufficient.

There must be a gas between the glass (not just air) and the glass type has to be more thermally insulating than normal window glass. Homes will have lower heating / cooling costs as a result but of course there will be increased building and renovation costs.