What is Homestar™?
Homestar™ rates new homes on a scale of 6 to 10 stars. A minimum 6 Homestar™ rating is the entry point for certification — and it's already a significant step above a standard Building code-compliant home.
The rating covers key aspects of a home's performance: health, comfort, and energy efficiency. Ratings are carried out by accredited Homestar™ assessors who independently verify that a home has been designed and built to meet the relevant standard.
A rating system designed for New Zealand homes
What does Homestar™ cover?
Homestar™ assesses homes across several categories including indoor environment quality (warmth, moisture, ventilation and overheating), energy and water efficiency, and materials. The rating focuses on what Homestar™ certifies — and is clear about what it doesn't cover.
A Homestar™ certification is confirmation that your home is designed to perform to a higher standard in the areas it covers.
Who manages Homestar™?
Homestar™ is managed by the New Zealand Green Building Council (NZGBC) — a not-for-profit organisation driving the transformation of Aotearoa’s built environment. Representing over 700 members, they advocate for sustainable, low-carbon buildings and run trusted building certifications like Homestar™ and Green Star, supporting the building and construction industry to create healthier, greener homes and buildings for all New Zealanders.
-
Homestar is New Zealand's independent rating tool for new homes. It certifies that a home has been designed and built to a higher standard than the building code — one that's designed to be warmer, drier, healthier, and more efficient to run. Homes are rated on a scale of 6 to 10 stars, with 6 being the entry point for certification.
-
The New Zealand Building Code sets the minimum legal standard for construction — but that minimum doesn't guarantee a warm, dry, or healthy home. A home built to code can still be cold in winter, prone to mould, and expensive to heat and cool. Homestar gives you assurance that your home is built to a higher, independently assessed standard.
-
Homestar certifies specific aspects of your home's design and construction — including indoor warmth, dryness, ventilation, energy and water efficiency, and materials. It's important to understand that certification covers these specific areas, rather than being a blanket guarantee across the entire build. Ask your builder or developer exactly what the certification covers for your home.
-
Homestar is primarily available for new homes, though ratings are possible for major renovations of existing homes. If you're renovating, get in touch with a Homestar professional to find out whether it's right for your project.
-
Building to a Homestar 6 rating adds up to 1.5% to your build cost — a modest upfront investment that varies depending on your home type and location. Some home types in some regions can cost even less to certify.
-
Independent analysis from Infometrics found that despite an upfront cost of up to 1.5% more to build, Homestar homeowners can expect to be better off within two to three years — through a combination of lower energy bills and discounted mortgage interest.
-
Various banks and lenders offer discounted green loans for homes that meet certain sustainability criteria. For example, ANZ offers a Healthy Home Loan package, which offers discounts on home loan interest rates for homes with a 6 Homestar or higher rating. Find out more about the ANZ eligibility criteria here.
-
Independent analysis from Infometrics shows a 6 Homestar home can save at least $296 a year on electricity bills compared to a standard building code home — and potentially much more depending on your home type and location. Factoring in electricity price rises, energy savings could reach between $580 and $1,500 per year by 2050.
-
Over a 30-year loan period, the combined savings from lower energy bills and discounted mortgage interest range from $62,800 for a terraced house in Auckland to $98,800 for a standalone house in Wellington, based on independent analysis by Infometrics.
-
Ask your builder or developer early — ideally before you sign your contract. Simply ask: "Do you build to a Homestar rating?" It's much easier and more cost-effective to include Homestar from the start than to add it later. You can also use our directory to find builders who are already certify to Homestar.
-
Look for the Homestar logo and star rating in the development's marketing. If you don't see it, ask the developer directly whether the development is Homestar rated.
-
Before signing your building contract, ask: "Do you build to a Homestar rating, and if so, what star rating do your homes typically achieve?" Also ask what the Homestar certification specifically covers for your home, and whether building to Homestar could help you access a discounted green loan.
Home buyer FAQs
-
A Homestar certification gives your buyers independent assurance that your homes are built to a higher standard — designed to be warmer, drier, healthier, and more efficient. It differentiates your builds in a competitive market and gives buyers a compelling financial reason to choose your homes, since various banks and lenders offer discounted green loans for homes that meet certain sustainability criteria.
-
As awareness of Homestar grows, a rating gives buyers a credible, independent signal that your homes are built above the building code minimum. It differentiates your builds in a competitive market — and because various banks and lenders offer discounted green loans for homes that meet certain sustainability criteria, it gives buyers a compelling financial reason to choose your homes over a standard build.
-
Building to a Homestar rating could make your development eligible for discounted green lending from major NZ banks. Talk to your bank about what's available for your specific project — rates and eligibility vary. See our Builders & Developers page for a list of banks currently offering sustainable finance options for Homestar-certified developments.
-
A Homestar rating is a credible, independently verified mark that your homes are built to a higher standard. Unlike marketing claims, it's backed by a third-party assessment process — giving buyers confidence and giving you a clear point of difference that's difficult for competitors to replicate without going through the same certification process.
-
Register as early as possible — ideally as soon as you know you're going ahead with an assessment. Early registration means the NZGBC team is aware of your project and can provide support and guidance throughout the process. It also makes it easier to incorporate Homestar requirements into the design from the outset, which is more cost-effective than retrofitting later.
-
A Design rating is carried out by reviewing your building consent drawings and specifications against Homestar criteria — it's useful for marketing your homes before they're built. A Built rating is carried out once the project reaches practical completion and confirms the finished home has been constructed in line with the Homestar rating. The Built rating is the only compulsory one, but most projects choose to do both.
-
Homestar assessments are carried out by accredited Homestar Assessors who are independent of the NZGBC. You can find assessors through the Homestar Assessor directory on the NZGBC website. Assessors set their own fees in addition to the NZGBC admin and audit fee — it's advisable to get several quotes before engaging one.
-
For new build projects, the NZGBC admin and audit fee covers both the Design and Built rating assessments. Use the fee calculator on the NZGBC website for an estimate based on your specific project. Note that Assessor fees are set independently and are not included in this fee.
-
Yes. For multi-unit developments where the same design is used for multiple dwellings, your Homestar Assessor can use a typologies approach — where only the "worst case scenario" of each typology is assessed, and that rating is then applied to all dwellings of that typology. This approach can significantly reduce assessment fees.
-
A Homestar Designer is trained to advise on and design homes that meet the requirements for Homestar certification. A Homestar Assessor has additional qualifications and is the only person who can formally carry out and submit a Homestar assessment for certification. If you're looking to build a Homestar home, you'll need to engage a qualified Homestar Assessor.
-
Several major NZ banks offer sustainable finance options for developers building to Homestar. These include ANZ, ASB, BNZ, and Westpac. Eligibility criteria and rates vary by bank and project — talk to your bank directly about what's available for your development.
-
A real-life example of a 6 Homestar development project realised a net saving of $148,640 over five years, purely from reduced interest costs on developer finance. The specific savings will depend on your project size, location, and lending arrangements.