Feature article

Q & A on Homestar rated homes

If you really want reassurance for a newbuild, see if you can find a Homestar rated home.

Ever heard of the New Zealand Green Building Council’s Homestar rating? It’s an independent rating tool for assessing the health, efficiency and sustainability of homes across Aotearoa New Zealand and it goes well beyond standard building code. The Homestar rating provides a clear framework for improving the sustainability and performance of homes, while reducing their environmental impact. 

As you go to buy a home, it’s worth knowing that there are strong financial incentives for buying a new home that has a Homestar rating, as well as giving you annual energy savings of an estimated $500 per annum, per household. ANZ Bank is currently offering interest rate reductions of up to 1% for homeowners who purchase a Homestar certified home. 

In practice, this means that if you bought a home for $880,000 with a 20% deposit and a 30-year loan term, you could save up to $3,863 on your repayments in the first year.

Matthew Cutler-Welsh, Business Development Manager - Residential, NZ Green Building Council would like to see the Homestar ratings align with the coalition Government’s fast-track consenting process. We asked him:

What has the takeup of Homestar rated homes been like in Aotearoa New Zealand?

The Homestar rating has had really good take up. We’ve seen exponential growth in the past ten plus years starting with a few hundred registrations in 2011 and in the first couple of years from developers and individual homeowners to over 6000 registrations in 2022 and 2023. Kāinga Ora has been a great leader in this space and brought building companies along with them.

Why is there a need for Homestar rated homes vs new homes built to the standard building code?

The big issue in most NZ houses is that they’re drastically underheated. When people move into a new home, they find it warmer and it’s better than an old house but it still has problems. There’s nothing in the building code to prevent moisture getting in or to prevent overheating which is becoming an increasing concern. The latest version of Homestar addresses both those issues, with the requirement for continuous ventilation and energy modelling to optimise performance.  

A Homestar rated home should be dry and comfortable and have lower power bills, which isn’t guaranteed with a new home just built to the building code.

With a Homestar rated home, we look at where the home is, if it’s close to transport, we also look at its resilience. Is it in a known flood plain, if so what strategies are there to mitigate this? Homestar also considers the environmental ratings of individual products and materials, accessibility and innovations such as EV charging and onsite electricity generation are also recognised. 

Can you retrofit a home to become Homestar rated?

The Homestar rating can be used for major renovations or a deep retrofit. If you’re replacing old joinery, insulating walls, adding air tightness and a heat recovery system, (investing $50,000 to $100,000), our modelling tool, the Energy and Carbon Calculator for Homes (ECCHO) is really useful. ASB has retrofit funding for existing homes that have a significant upgrade, offering up to $80,000 that people can draw down to invest in improving their home. Westpac also offers interest free loans for house retrofits.

If you’re hoping to get a lower interest rate on your mortgage because of your Homestar rated home, you should think about that early in the renovation process. If you’re improving the home and using an architect, then tell them you want it to be Homestar rated. If you leave this too late in the design phase then you’re unlikely to get a Homestar certificate. We might recommend design changes while in the planning process and we collect evidence during construction.

What other organisations are interested in Homestar rated homes?

Retirement villages, run by companies like Bupa, Metlifecare, Arvida and Oceania, understand the value of the Homestar rating. They’re in it for the long haul and want to look after their buildings, and retain them. Property companies in the build-to-rent sector such as Simplicity Living and New Ground Capital are also interested in Homestar rated homes. Again, they see the value in building homes to these standards and are committing to long term home ownership so they want these homes to last.

I’ve heard of a 10 Homestar rating - how does this differ from a 6 Homestar rating?

If it’s 10 Homestar rated, it’s world leading, you’re ticking every box and likely to be going above and beyond in several areas. Recent examples include Fletcher Living’s LowCo demonstration house and Nelson architect Nathan Edmonston’s own home. https://nzgbc.org.nz/case-studies/crathie-place-nelson

We talk to Alastair Meehan, development manager at Hutt City Council-owned Wellington developer, Urban Plus, which is delivering 20, 6 Homestar-rated townhouses in the Lower Hutt suburb of Waiwhetu to the market in the coming months. The developer has committed to building only this standard of home from now on. The Brook St homes are near Waterloo train station and are being marketed to first home buyers and owner-occupiers, rather than investors. We asked him:

What main differences will home buyers see between a standard new-build and a new 6 Homestar rated home?

The quality of the insulation is one of the easiest to understand and noticeable differences between a standard new-build and a new Homestar rated house, with higher R-values (thermal resistance rating) than would otherwise be required. Thermal efficiency in a 6 Homestar rated home is further improved through the use of thermally broken windows which include a thermal break to limit heat transfer through the aluminium frames and reduce condensation build up. Lastly, the development is being built with a strong focus on sustainability in terms of material and fixture selections, including FSC(Forest management certification) timber, eco-friendly paints and water efficient tapware and fittings. All this means, with a Homestar rated home, you’ll have a more comfortable home year round, reduced energy bills and water bills in towns where water metres are used.

Is a Homestar rated new home going to be more expensive to buy than a standard new-build home?

The homes are marginally more expensive to build, noting the higher quality materials and compliance costs associated with a Homestar rating, however we choose not to pass this cost onto purchasers. Instead, we aim to set our sales price at, or slightly under market rate. Our aspiration is for people to be in affordable housing so there’s no uplift in sales price for a 6 Homestar rated home. In practice, this means that purchasers are getting a lot of additional features at no extra cost. With 20 homes available at our Brook Street development, prices start at $649,000 for a two bedroom townhouse and $795,000 for a three bedroom townhouse.  

The 6 Homestar rating is a point of difference Urban Plus can talk about with home buyers. As it’s getting closer to completion date, we’re getting more inquiries and drawing attention to the 6 Homestar rating which seems to be appealing to people.


Gill South
Gill South