Choose Your H1 Calculator

Select the appropriate calculator based on the applicable version of H1/AS1 for your project.

H1/AS1 – 5th Edition

Transitional compliance pathway

H1/AS1, 5th Edition remains a valid compliance pathway until 3 November 2026.

Use this version for projects designed under the previous standard or where consent documentation references Edition 5.

Open 5th Edition Calculator

H1/AS1 – 6th Edition

Current compliance pathway

H1/AS1, 6th Edition is the current standard for new building work and energy efficiency compliance. Use this version for all new designs unless a transitional pathway applies.

Open 6th Edition Calculator

Who is this calculator for?

What is H1 Energy Efficiency?

Clause H1 of the New Zealand Building Code sets minimum requirements for energy efficiency and thermal performance in buildings. It defines how insulation, glazing, and other building envelope components must perform to reduce heat loss and improve indoor comfort.

H1/AS1 is an Acceptable Solution that provides a pathway for demonstrating compliance with Clause H1. It applies to housing and small buildings, and includes requirements for different climate zones across New Zealand.

Key Changes in H1/AS1 – 6th Edition Calculator

H1/AS1 Edition 6 introduces updates to improve flexibility, clarity, and alignment with current best practice. Key changes relevant to the calculator include:

These updates mean that results from the Edition 6 calculator reflect the most current acceptable solution under the New Zealand Building Code.