There are lots of things to consider when planning your new home or major renovation and one area rightfully deserving to be high on the list is sustainable building solutions.

Incorporating good environmental design before you commence a project is vitally important for the conservation and welfare of our limited natural resources, can save you money and can avoid costly alterations later on. Homestar is the official rating and certification programme, operated by the New Zealand Green Building Council, that evaluates the environmental attributes of New Zealand’s stand-alone homes in terms of energy, health and comfort, water, waste and more. The rating is on a scale from one to 10 (one being very poor and 10 being world excellence). Many of the more problematic old kiwi homes sit in the 2-3 star region – so there is plenty of room for improvement.

With the introduction of a rating system, homeowners are able to use Homestar™ to independently demonstrate true value of their home. As the market develops and demand increases, homes with a higher star rating will be able to sell for more money.

Many overseas countries are now requesting that homes be officially certified before they can be bought or sold, and it is expected that Homestar will be one of the biggest changes to the New Zealand residential market in years to come. So here are some useful tips and insights to help you secure a good Homestar rating for your property.

It is important to engage a certified Homestar professional to help you get the best rating possible within your given budget, and more importantly given your particular needs and aspirations. Homestar looks at many aspects of environmental and social sustainability within a home. It’s not all just about energy performance, although of course energy efficiency is one of the more heavy weighted sections in the assessment programme.

The public website is a simplified version of the official certification programme. The online self assessment helps those wanting to learn about the basic issues or to do a quick evaluation of their current property.

Where to go

If you are undertaking major renovations or building a new house, then you should look directly at the certified assessment version. You will have to contact a Homestar certified professional to access this information, as it is not available online. You can either contact a Homestar practitioner, who can help you design your house and prepare for assessment, or a Homestar assessor, who can certify your property and give it an official rating. The ideal solution is to contact a person or company that is both a practitioner and assessor, so you get your complete design consultancy and assessment preparation support, as well as your official certification while only dealing with one person. Some professionals operate locally and some operate nationally. You will find a list of qualified professionals at

The Homestar assessment framework is divided into seven main sections. Each section is then subdivided into a number of “credits”. A quick overview of the framework can be:

[box] Energy, health and comfort

Looking into energy efficiency throughout the house (space and water heating, whiteware, lighting and renewable energy), moisture control, noise control and useability for disabled people.


Focusing mainly on water conservation within the home, including rainwater harvesting and grey water recycling wherever possible.


Looking at waste management during the construction process as well as from user occupation.


Ensuring you select environmentally certified materials, helping provide healthy indoor air quality and a more environmentally friendly supply chain for your home.


Looking at items such as storm water runoff control, native ecology, access to regular transport connections and local amenities, etc.


Looking at health and safety issues within the home and the selection of environmentally responsible building contractors.[/box]

The assessment framework also has mandatory minimums when it comes to the “whole of house thermal performance calculator”, water efficiency and moisture control credits. It is paramount to ensure these are addressed upfront, right at the beginning of the design process. To perform well it will be necessary to address passive thermal design principles, increase the insulation levels in walls, floor and ceiling, and select thermally efficient window frames with double glazing. One of the simplest ways to achieve points is to purchase products and materials that comply with the requirements set in Homestar. Important aspects to consider when selecting products such as paint, carpet, joinery, insulation and adhesives, among others are:

  • Does the product have a compliant environmental certification ecolabel (e.g. ECNZ, FSC)?
  • Does the product have low volatile organic compound and low formaldehyde emissions?

An easy way of finding compatible products is to refer to the EnviroSpec website and select the tab search Green Star NZ / Homestar compatible products.
You can also look for product labels indicating the product has been reviewed and can be safely specified for your Homestar project. One such example is the Daiken custmwood superfinish, a great product suitable for kitchen and bathroom joinery, with FSC certification and low formaldehyde emissions. Scan the QR code with your smartphone or tablet to be taken straight to the documentation online.

Last but not least, ensure you or your builder keeps all receipts demonstrating which product has been bought, and leaves all the product labels on the products themselves (e.g. energy star rating on your fridge) to enable the assessor to quickly validate your points. Keeping receipts and tracking documentation is even more important for generic type products, such as plasterboard or paint.

For example if you don’t keep the receipt and the product certificate document for the paint you have purchased, it will be very hard for the assessor to know what brand and type of paint you have used once it is dried on the wall.

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