Homestar is an independent rating tool that assesses a combination of a home’s performance and its environmental impact.
How does Homestar work?
As a rating tool, it certifies the health, efficiency, and sustainability of New Zealand homes based on their set of criteria. A home is rated on a 1-10 scale: a rating of 1 Homestar means it needs significant work, and 10 Homestar indicates international best practice. Most existing New Zealand homes only achieve a 2-3 Homestar rating.
Homestar was created to give confidence that the home will be more sustainable, easier to keep warm and, depending on how the resident chooses to live and use its features, have lower running-costs.
Homestar awards points across various credits to rate a home’s performance and environmental impact. There are mandatory minimum requirements around keeping the home, warm, dry, well ventilated, and resource-efficient. Otherwise, the tool is flexible. An important aspect to note is that credits are open to various combinations to reach the points required to achieve the desired rating.
Homestar ratings do reward good design principles such as good orientation for sun, high levels of insulation and controlling moisture which are key to creating a healthy, efficient home.
Homestar also considers the build process to reward activities such as minimising and sorting of waste onsite during the construction process.
For comparison, a 10 Homestar rating (100 points) recognises world leading standards for design, construction, and efficiency in operation. A 6 Homestar rating (60 points) recognises a home that has been built above the current standards set by the New Zealand building code.
How much does a rating cost?
Homestar ratings are carried out by Homestar Assessors. While they are trained by the NZ Green Building Council (NZGBC), they are third party consultants, external to the NZGBC and so will negotiate their own fees. As with any professional service, you may wish to get several quotes and compare suppliers before engaging a Homestar Assessor to carry out the work.
Homestar and Passive House
Homestar is a rating tool for a wide range of energy and sustainability factors, whereas passive house is a building methodology targeted specifically at comfort, health, and low energy costs.
You can choose between Homestar and passive house but building to passive house principles is arguably the best way to achieve a lot of what Homestar rewards, so they effectively complement each other. It’s inaccurate to consider them as rival building methods.
