Building a Homestar rated home helps to ensure a healthier, warmer, drier, and more comfortable home that uses less power and water than a similar home built to the minimum standard of the New Zealand Building Code.
It’s widely acknowledged that the Building Code is woefully inadequate, meaning hundreds of thousands of New Zealand homes do not meet basic standards for health, warmth, ventilation, and operating efficiency for our climate.
A warm, dry, healthy home is a basic human right. This is why the New Zealand Building Council offers Homestar – a certification standard that allows designers, architects, and builders across the residential sector to look ahead to build better futures for our whānau to live, work and play.
Beth Chaney-Walker
Chaney & Norman Architects | 8 Homestar homeowner
To receive a Homestar rating, a house must meet additional performance and sustainability requirements above and beyond the New Zealand Building Code.
Homestar provides a clear framework for better design and build for a more efficient home. It’s an independent rating tool for assessing the health, efficiency, and sustainability of homes across Aotearoa New Zealand.
Homestar rates on a scale of 6 to 10 so that homeowners and professionals can better understand where their home or design fits and steps they can take to improve to a better, healthier standard. See below the types of features added to receive various Homestar ratings.
Homestar provides a clear framework for better design and build for a more efficient home. It’s an independent rating tool for assessing the health, efficiency, and sustainability of homes across Aotearoa New Zealand.
Homestar rates on a scale of 6 to 10 so that homeowners and professionals can better understand where their home or design fits and steps they can take to improve to a better, healthier standard.
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A study by consultants Aurecon, with costings by quantity surveyors Kwanto, found the cost of meeting a 6 Homestar v5 rating compared to the latest Building Code energy efficiency requirements was between 0-1.3% depending on where you are in the country.
The report found the cost, excluding fees, of building to Homestar 6 varied from no additional cost for a 2 bedroom terrace in Christchurch and Wellington, to a maximum of 1.3% extra for a 4 bedroom standalone home in Christchurch.
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The table below sets out the estimated energy bill savings by using Homestar for 2 standard house designs (unit and standalone), across 3 climate zones (refer to Aurecon Homestar v5 Review report). The savings estimates are based on an averaged calculation of New Zealand house heating and hot water use. Energy savings will vary depending on the actual size and layout of your home and how you operate it, in particular how warm you keep it in winter and how much hot water you use.
| Location | Homestar 6 | Homestar 7 | Homestar 8 | Homestar 9 | Homestar 10 | |
|---|---|---|---|---|---|---|
| Unit | Annual bill saving $ per year | Annual bill saving $ per year | Annual bill saving $ per year | Annual bill saving $ per year | Annual bill saving $ per year | |
| Climate zone 1 | Auckland | $416 | $575 | $652 | $724 | $806 |
| Climate zone 3 | Wellington | $526 | $744 | $862 | $955 | $1,070 |
| Climate zone 5 | Christchurch | $554 | $844 | $1,010 | $1,148 | $1,296 |
| Standalone House | Annual bill saving $ per year | Annual bill saving $ per year | Annual bill saving $ per year | Annual bill saving $ per year | Annual bill saving $ per year | |
| Climate zone 1 | Auckland | $296 | $520 | $629 | $730 | $846 |
| Climate zone 3 | Wellington | $644 | $950 | $1,118 | $1,248 | $1,411 |
| Climate zone 5 | Christchurch | $760 | $1,169 | $1,401 | $1,597 | $1,806 |
This table is only intended to be a guide to the energy savings we think using Homestar can provide to you based on modelling results which are only an interpretation of the potential performance of any home.
Whether you're a builder, architect, designer and/or accredited Homestar professional, you'll find the information you need to assist you with the Homestar process
The main requirements of a Homestar home over and above a stand code compliant home are:
Continuous mechanical ventilation to ensure consistently good indoor air quality.
Continuous insulation, including thermal breaks in the building envelope to minimise the risk of condensation, which leads to mould.
Carbon: Accounting for both embodied and operation carbon.
Cool: design to avoid overheating.
Homestar ratings are carried out by Homestar Assessors. While they are trained by the 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 your rating.
Find out more about the assessment process and fees then find assessors in your area through our Homestar Assessor directory.
Homestar is a holistic tool that awards points across various credits to rate a home’s performance and environmental impact. There are mandatory minimum requirements focused on keeping the home, warm, dry, well-ventilated, and operating efficiently. Otherwise, the tool is flexible. The credits are open to various combinations to reach the points required to achieve the desired rating.
The home needs at least 60 points to achieve a 6 Homestar rating, which is the minimum standard that can be certified. Depending on its location across Aotearoa, a 6 Homestar rated home will be easier to keep warm and healthy, more cost effective to run, and more environmentally friendly than a home built to the Building Code. A 10 Homestar rating indicates a market-leading home.
Housing is a fundamental human need. New Zealand has high levels of substandard housing, which has resulted from poor regulation of minimum housing standards and lack of maintenance. In 2008 the Business Council for Sustainable Development identified that at least 1 million of the 1.6 million existing homes in New Zealand were poor performers - they are cold, damp and difficult to heat.
New Zealand has the second-highest rate of asthma in the world, often caused by poor quality housing. Efficient homes can also help you save money on running costs through energy and water savings.
An LED can pay for itself in a little over a year (Consumer NZ) and save $100-300 over the life time of the bulb (GenLess).
Replacing an 18-litre-per-minute showerhead with a 6-litre-per-minute showerhead can cut your hot water bill by $293 a year, while still offering a comfortable, effective shower (Consumer NZ).
A dripping tap can waste up to 33 litres each day (Watercare).
It’s more cost-effective to find a Homestar Assessor and start incorporating sustainability at the beginning of a project’s design stage. Many aspects of Homestar are related to the design of the building, and your Assessor can advise you throughout the process. Reviewing the different credits available in the Homestar Technical manual early can give ideas of what to include in your plans.
- Download latest technical manual
Find a Homestar Assessor through our Homestar Assessor directory.
Homestar was developed for new homes and requires them to be designed and built to a standard higher than the building code. Various pieces of evidence are required during the building process. It is generally not possible to get a home rated if Homestar has not been considered at the design stage. Get in touch with a Homestar Assessor to discuss the possibilities.
Only Homestar certified buildings can claim Homestar certification or use Homestar certification marks, unless pre assessed under volume certification.
If a project is still in the certification process, you cannot use the Homestar certification mark, however the following phrases can be used, providing the registration process is
complete:
‘X building is targeting a Homestar rating’
‘X building is targeting a Homestar Design rating’
‘X building is targeting a Homestar Built rating’
Application: Plans, drawings, hoardings, brochures, websites, real estate advertising and other marketing material that relates to the specific rated home or development. The certification mark may also be applied as a sticker, decal or other materials on the
home itself.
When written in text, Homestar is always written as one word with a capital H (never ‘Home Star’ or ‘homestar’).
Unless a project has been certified by the New Zealand Green Building Council, it is not permitted to reference compliance with the requirements of Homestar.
Projects that claim to meet the requirements of a Homestar rating tool but are not certified cannot use the Homestar trade mark.
A project should not claim to be “Homestar equivalent” or “Project designed/built to Homestar standard” where a project is not verified or certified by the New Zealand Green Building Council.
Any use of the Homestar trade marks in such circumstances is in breach of our rules and may amount to trade mark infringement and ‘greenwash’.
Homestar Innovations are a pathway for recognising initiatives that are not currently included in the Homestar certification tool.
Check out our Homestar Technical Resources to find out more.
No. Homestar ratings are only awarded to whole dwellings. Materials and products do play an important role in the environmental impact of building, and an entire category of Homestar is dedicated to assessing the Materials used on a project. Find out more about how products and materials contribute to Homestar in our Homestar Technical Resources .
Check out our Homestar qualifications and upcoming courses to find out more
For multi-unit developments where the same design (typology) is used for multiple dwellings, a Homestar Assessor can use the typologies approach. In this instance only the worst-case scenario of each typology is assessed under Homestar. The rating for that typology is then applied to all dwellings of that typology. This approach reduces the Homestar fees
If you're building a new Homestar rated home, you are building to a standard above the current Building Code. All of the requirements of the Residential Tenancies (Healthy Homes Standards) Regulations 2019 (HHS), and the Residential Tenancies (Smoke Alarms) Regulations 2016 (RTA) are fulfilled by the current Building Code, except for the efficient space heating requirements. You'll need to check the heating source complies with the rental standards by using the Heating Assessment Tool.