Changes to insulation rules aim to cut upfront building costs - and give designers more choice

Building and Construction Minister Chris Penk says Kiwis have been locked out of affordable housing by a five year spike in costs.

Penk says MBIE's completed an energy efficiency standards review -- proposing changes he calls commonsense.

Existing rules still apply to new builds, but added flexibility could allow more insulation in the walls to balance out less under-floor.

Another key change -- to calculate whole buildings, not individual components -- could cut 15-thousand dollars off upfront costs.