How much does a high end eco-renovation cost in New Zealand?

ARTICLE Libby Schultz

If you have a bigger renovation budget, there’s even more you can do. You might even aspire to join New Zealand’s growing ‘superhome movement’ – and create another 10-star home. You can also afford to get really serious about energy-efficiency; with the likes of double-glazing, low-E glass, and insulation that offers the highest R-value. You might also create stunning designer effects with a ‘thermal sink’ - concrete slab floors that absorb and store heat.

What features does a Superhome have?

The 10-star Homestar dwelling in Christchurch, at a size of 140sq metres and with three bedrooms and two bathrooms, cost around $400k to build.
Architectural designer Bob Burnett says this equates to about a 10% premium on standard building costs – and that price will only come down.
“As these types of homes become more mainstream, they will also become cheaper to build.”
And the ongoing savings are significant. If you lived in Bob’s 10-star rated home, your power bill would literally be reduced to nothing. Even achieving a 6-or-7 Homestar home will cut your power bill in half.

How do I create an energy-efficient home?

One of the most powerful ways to create an energy-efficient home is often overlooked – even though it’s available to everyone, and completely free.
Passive solar design should be top-of-mind when you’re sitting at the drawing board planning your new build or major renovation. Good orientation for the sun is vital, and costs little or nothing to incorporate into your design.
“Your home’s site positioning and design should capture as much direct sunshine as possible,” says one of Refresh Renovations' eco-design specialists.
The ideal position is for the long axis of your home to lie in the east-west direction, with the living spaces facing north. Of course, not all sites will make things that easy. If your section is more challenging, you’ll need to find more strategic ways to capture the passive energy. But there’s always a solution, she says.
“There are many different ways to capture passive solar energy - even on a tricky or sloping site. It’s always worth consulting an expert in energy-efficiency; they have all the modeling tools and can highlight the most cost-effective solution for you.”

Can I make my roof 'green' too?

Although ‘green roofs’ are a fairly modern phenomenon, a version of them has always existed in New Zealand. Maori built whare paruparu (dirt houses), and European settlers commonly made dwellings from sod.
These days, a green roof is essentially plants and vegetation grown on a roof. They may be ornamental gardens, or naturally vegetated. Although more common in commercial buildings, they are becoming increasingly popular with home-owners.
Living Roof Aotearoa promotes the many benefits of the green roof movement. For the home-owner, living roofs provide insulating properties (and a cooling effect when needed), as well as helping with stormwater management and sustainable drainage.
They can also improve a region’s biodiversity, by providing much-needed green space in urban or industrial areas – and a habitat for plants, invertebrates and birds.
Costs will vary depending on the type of green roof you want. But Auckland-based company Greenroofs Ltd can provide you with a ‘plug plant’ roof, comprised of either sedum plants or NZ natives, with prices starting around $200 per sq metre plus gst.

How much do solar power systems cost?

Previously the sole domain of alternative-lifestylers, solar power has gone mainstream. It’s becoming an increasingly popular – and affordable – way to power your home.
SkySolar is an Auckland-based company that provides home-owners with total solar systems (sometimes referred to as “off grid”), as well as grid-tied systems, and hybrid systems. The latter means you can still be connected to the grid, but also have battery back-up to use in the evenings or when there is a power cut.
Nick Freeman, SkySolar managing director, says approximately 6,000 Kiwis have made the move to solar – and the business case is improving all the time.
“New builds can be quoted up to $50,000 to have lines connected to their site, which is comparable to the cost of an off-grid solution.
“Hybrid systems give you the best of both worlds – allowing you to stay connected to the grid while having your own battery back-up. But for now, most home-owners install a grid-tied system which provides a base to move towards further independence as technology improves.”
A grid-tied system from SkySolar costs around $10,000 for a basic 3kW system, which will provide around 50% of an average home’s power use.

What to do about waste? 

Lastly, if you are building or renovating – remember your responsibilities when it comes to waste materials. According to Level, approximately 850,000 tonnes of construction and demolition waste is sent to landfills each year.
Keep the “three Rs” as your mantra - reduce the amount of waste you bring onto your site; re-use existing building material wherever possible; and recycle materials that come out of your renovation.
Your old bathroom vanity may be past its style use-by date-for you, but there’s no need to send it to landfill. Someone else will always be pleased to take it – whether you sell it for $1 on Trade Me, or post it on Freecycle.

For information on how to achieve a healthy home with smaller budgets, read our mid-range eco-renovation project estimate or our basic eco-renovation project estimate. 

Get in touch with Refresh to discuss your home renovation project

If you would like to discuss eco-friendly options and ideas for your next renovation project, please use the enquiry form on this page to provide us with your contact details. We will get in touch with you at a time that suits you to discuss your project. If you would like to provide us with more information about your project, we have a more comprehensive enquiry form on our "Get in touch" page too.
*Costs are rough estimates and are subject to change. For a fixed-quote accurate to your specific project, please consult your local Refresh Renovations specialist. All Refresh Renovations franchises are independently owned and operated.