Big Building Code changes see builders up-skilling

There are some substantial changes coming for the Building Code, and many builders are upping their skills and knowledge ahead of these updates by using the new updated version of Homestar, the green home rating scheme.

These much needed changes to the Code are intended to make new homes in Aotearoa better insulated, improve fresh air circulation, and slash the carbon pollution from our homes.

The average new house in New Zealand emits five times too much carbon pollution, and the revamped Homestar will play a key role in tackling this. Both the new version of Homestar, and the changes to the Building Code reflect the rapidly growing demand for carbon emissions to be slashed.

The government is working to reduce the carbon pollution from homes and buildings, which are responsible for 20 per cent of climate heating pollution in New Zealand.

Builders building homes to Homestar will get valuable experience in building above the current Building Code, and readying themselves for the big new requirements of the enhanced Building Code, which is heading down the slipway. The new version of Homestar aligns with the government programme, called Building for Climate Change. This will allow builders using Homestar to develop the skills and knowledge needed for upcoming changes.

Builders constructing Homestar rated homes can now demonstrate how they’re using sustainable materials that don’t pump out huge amounts of carbon pollution when manufactured. This type of carbon pollution, which has been belched into the atmosphere during the production of building materials, is often called ‘embodied carbon’. The newest version of Homestar includes an embodied carbon calculator, helping builders and designers to work out the levels of carbon emitted during the manufacture of the building materials. Calculating the amount of carbon pollution resulting from the production, assembly and transportation of building components can be quite tricky and this embodied carbon calculator is at the forefront of helping New Zealand builders standardise how this should be done.

The other way homes emit carbon pollution is through using energy to power and run a home. These emissions are often called ‘operational carbon’.

For operational energy use and carbon emission calculations, the new Homestar includes for the first time ever an online Energy and Carbon Calculator for Homes (ECCHO). ECCHO will bring some of the robust methodology and science of the Passive House Planning Package (PHPP) calculator to designers and assessors across Aotearoa. ECCHO has also been listed as an approved modelling tool under the changes to Building Code clause H1 that were published late last year, and that become mandatory from the end of 2022.

The New Zealand Green Building Council offer an array of regular education and training sessions, including on the new Homestar. The not-for-profit organisation also has a host of on demand educational videos available, which are free to members. Find out for at https://www.nzgbc.org.nz/eventshub. Almost 5,000 new homes were registered under Homestar in the last year.

If you’d like to know more about the carbon calculators, or anything else about Homestar, then please get in touch with the Green Building Council’s Homestar expert Matthew Cutler-Welsh on 09 951 0732 or drop a line to the Homestar team on homestar@nzgbc.org.nz.

New Zealand Green Building Council (NZGBC) is a not-for-profit team of people who are passionate advocates for better buildings, because we know that better buildings mean healthier, happier Kiwis. For more information visit www.nzgbc.org.nz