19 Sep 2018

Tips for eco-friendly building and renovation

From Nine To Noon, 11:28 am on 19 September 2018

Most New Zealanders are interested in living and building sustainably, but moving away from our "quick bang for buck" mindset is a challenge, sustainable building author Melinda Williams says.

She has written about sustainable building for a long time, but decided to write a book, Eco Home, when - while looking to give her 1970s Auckland house an eco-friendly facelift - she couldn't find the relevant information all in one place.

44317184 - solar panel cells on the roof of a new house agains blue sky.

Williams says solar panels are unlikely to be very economically realistic for most New Zealand homes. Photo: lighthunter/123RF

When it comes to a sustainable renovation or build there's no 'one size fits all' approach, but people should expect to invest in the performance of their house, she says.

For this upfront investment you'll get a long-term payoff, she tells Nine to Noon's Kathryn Ryan.

The most eco-friendly approach to take will depend on the type of house, the site, your time and money constraints and your priorities, Williams says.

New Zealand "well-established" system for rating the warmth, dryness and health of a home Homestar - is a good starting point.

Most homes built prior to 2000 have a home star rating of 2 or 3, and those built to code today often have a rating of 4. The NZ Green Building Council recommends homes be built to a rating of 6 or 7.

Williams says a home like that will cost about 1.5 percent more to build, but save you $800 to $1000 in bills every year after that.


More about sustainable, healthy houses:

The main problem with the existing houses in New Zealand is that many are cold, damp, drafty and inefficient, Williams says.

Most people don't really know what their houses are made of or how they perform - and when it comes time to renovate they tend to focus more on its appearance, but Williams says that's short-term thinking.

Eco Home by Melinda Williams

She recommends getting to know the basics of your house - its insulation, ventilation and how it uses electricity, gas and water.

You can get an assessment from an eco design advisor who will come out and make quick and easy recommendations for either day-to-day energy-saving measures or renovations.

Building new is an opportunity to start out sustainably, Williams says.

Many people aren't aware of how much construction waste goes to landfill, but pre-planning which building materials can be reused, repurposed or recycled can reduce a lot of it.

"Talk at a really early stage to your building or designer or draftsman … say to them upfront 'we want to save and recycle as much as we possibly can and we'd like you to work with us to do that'."

Materials are commonly over-ordered - often by 20 percent - with excess disposed of at the end, she says.

Wallboard often goes to waste, but if it's kept in reasonable condition it can be recycled and broken down to gypsum dust, she says.

"As long as it's been looked after during the construction process and hasn't been allowed to lie out on a lawn and get dirty, it's very recyclable."

Williams is saving over $400 a year in electricity costs after replacing the 40 halogen downlights in her house with low-wattage LED lights.

She was interested in getting solar panels, but because of the property's situation and abundance of neighbouring trees, says she struggled to even get someone out for a quote.

"For a lot of people, home solar is not an economical proposition.

"While solar power is a really positive technology, in New Zealand it's still more viable for commercial or institutional organisations where solar power is going to be used during the day and they've got big flat roof spaces."

Williams says her message is simple: "The things that improve the performance of your home will also save money over the long term".

Melinda Williams recommends people take a look at the free Consumer article Are solar panels right for your home?

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