How much does a mid-range eco-renovation cost in New Zealand?

ARTICLE Libby Schultz

So, you’ve budgeted a handy little sum for home improvements?
But to get the most eco-bang for your buck, with a mid-range budget, your first priority is to improve your home’s insulation. We know, it’s hardly the most exciting aspect of renovating - but it is absolutely critical to the health of your home. After all, there’s no point having the hottest new paint colours if you’ve got condensation dripping down your walls. Once we’ve got insulation sorted, we look at other eco-ideas for a mid-range budget.

How essential is insulation?

“Insulating your floor and ceiling is the most important thing you can do to improve your home’s health and reduce your energy bills,” says Mary de Ruyter from the New Zealand Green Building Council.
At a minimum, your ceiling insulation should be 12cm thick, cover the entire ceiling, and be dry and undamaged. Likewise, your underfloor layer should have no gaps, and sit up hard against the underside of your floorboards.
GreenStuf® is a New Zealand-made insulation product with great eco-credentials. The 100% polyester material is soft to touch (like a duvet), and doesn’t contain any added chemicals or fibres to breathe into your lungs. It’s made from a minimum 45% recycled PET plastics, and is recyclable at the end of its life.
GreenStuf® costs around $3,000-$3,500 to install for an average-sized house. Or, if you meet the criteria, the Warm Up New Zealand project is installing it in selected homes at little or no cost.

How green is the Building Code?

Everybody building a new house, or undertaking a major renovation, needs to meet the requirements of the New Zealand Building Code. So, how sustainable is it?
“The main focus of the Building Code is to provide basic levels of health and safety,” explains Mary de Ruyter.
“For instance, it requires a minimum level of insulation – and basic standards related to heating, lighting, ventilation, internal moisture and sound. But you need to look at other standards, such as the Homestar rating. A house that meets the minimum Building Code is equivalent to about a 3-4-star Homestar rating.”
The different Homestar criteria are: energy, health and comfort; waste; home management; materials; site; and an optional innovation category. Your home gets an overall rating on a scale of 1-10. A house that meets the minimum Building Code is about a 3-4 Homestar rating.
Curious as to how your place would stack up? Then register for myHomestar at the Homestar website and take the free, 20minute self-assessment quiz. You’ll receive a report with your current Homestar rating, and specific recommendations on ways to improve your home.

What type of eco painting materials can I use?

Planning a paint job, either inside or out? As you’d expect, paint comes in many shades of green. You’ll want to choose paints that have a low or zero VOC rating (which stands for volatile organic compounds).
“Take a look on your paint can labels – the lower the VOC content, the better,” says Mary de Ruyter.
“Also, look for paints that have certification from Environmental Choice New Zealand, indicating a smaller eco-footprint through the life cycle of the product.”
The Natural Paint Company is a small Christchurch-based company that makes a range of paints, oils, waxes and varnishes. They are not only VOC-free, but they’re made from natural ingredients such as plant oils, waxes, tree resins and china clay.
Owner James Mount says more home-owners are seeking out paints that are free of toxins.
“We have paints for pretty much any situation – including enamel pants for exteriors and high-moisture rooms. And because we use natural ingredients, our customers also tell us our paints smell really nice!”
All this eco-goodness is only marginally more expensive than standard paint. A 10litre bucket of interior wall paint from the Natural Paint Company retails for around $250.

What options do I have for outdoor eco-renovations?

Let’s take your mid-range budget outdoors – what are some ideas for improving your eco-credentials?
You might want to think about installing a greywater system. As well as reducing the load on regional sewerage systems, It’s a cheap source of garden water.
Kiwi company Natural Flow provides a simple eco-waste water and sewage system that is aerobic - and therefore odourless - and requires no power to run. It separates the grey water (from basins, baths and showers) and black water (from the kitchen sink and toilets); and converts the latter into water soluble nutrients.
Co-owner Dean Hoyle says while home-owners are increasingly keen to do their bit for keeping waste water out of the city waste system – they’re equally keen on the cost savings.
“If you’re in an urban area, you’re paying for every litre you use; and if you’re on tank water, you obviously want to conserve it.”
A grey water system from Natural Flow costs around $5,000-$6,000 installed; while a combined black/greywater system is around twice that.
Some local authorities in New Zealand encourage greywater recycling, but others don’t – so you’ll need to check with your local authority.

With a bigger budget, read the project estimate for high-end eco-renovation costs. Even with a smaller budget you can begin to make your home eco-friendlier; read basic eco-renovation estimate to find out how.

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.