Increase in H1 requirements from 1 May 2023
24 April 2022
In November 2021, the Ministry of Business, Innovation and Employment (MBIE) announced increases to the requirements for roof, window, wall, and underfloor insulation. The changes aim to reduce the amount of energy needed for heating residential homes by approximately 40%, delivering warmer and drier homes that are significantly cheaper to heat while generating carbon savings.
The changes included an increase in the number of climate zones from three to six, and increased insulation requirements for roofs, walls, floors, windows, doors, and skylights. They also provided a new compliance pathway for heating, ventilating and air conditioning (HVAC) systems in commercial buildings.
Following MBIE’s public consultation in June 2022, Master Builders, along with many sector stakeholders, were able to request a six-month extension to the transition time to comply with the new insulation requirements for housing.
The extension ends on 1 May 2023, resulting in an increase to the performance requirements for wall, floor, and roof insulation for new building work in housing.
Requirements for window and door insulation in housing will also see an increase on 1 May 2023 and will be required to meet the final increased performance levels in all parts of the country by 2 November 2023.
The staged requirements are set out in the table below. Find further information on the timeframes and requirements of the H1 changes.

Master Builders is currently organising a webinar with MBIE in May to help members better understand the implications of the H1 requirements and how these will affect building projects.
We will send out the webinar invitation to all members once the date and time are confirmed. Please stay tuned.
Ngā mihi
David Kelly