Energy Efficiency: 10 ways to eco-renovate your home

A renovation on Waiheke Island designed by Bull O'Sullivan Architects. The interior cladding in this home is made from salvaged timber. Photo / Simon Devitt

Things have changed at home. Children have arrived (or left), you’re going to write your novel and need your own office, or perhaps you just need some of that indoor/outdoor flow? Here’s Element’s 10 recommendations for an eco-renovation.

Building can be a wasteful business, so it's worth considering how to make the impact of your modifications as small as possible, while upgrading your home to be more energy efficient than it was.

1. Consider staying within your footprint
Infamously, renovations can be cripplingly expensive (the current figure hovers around $4000 per square metre, compared to $2800 for a new build. For this reason, a modification is worth considering with respect to your existing floor plan.

Instead of planning additional structures, look at how your space can be reconfigured - it's easier and cheaper to move an internal wall than an exterior one. Small spaces can be made to accommodate many possibilities, but engaging an architect is important for a project which demands intelligent design.

2. Get an energy audit
Before you begin, consider how to make your home as energy efficient as possible - it will pay dividends long term through power savings.

There are a couple of options for energy audits. Homestar is a rating system for environmental and energy efficiency in new and existing homes. Assessors are experts on building science and technology and are also connected with green-minded suppliers, who offer discounts through the Homestar scheme. Alternatively, get in touch with Auckland Council eco design advisor Eion Scott (0508 326337), who will arrange a free two-hour consultation.

3. Pre-loved materials
Turn your attention to the materials used in the renovation. The hacking down of almost every decent-sized native tree in this country by our forebears means there's a large supply of character timber which has been harvested from old homes, and can be purchased from salvaged timber yards. It adds instant gravitas to a home, and a juxtaposition between old and new can form a striking impression. Also keep an eye out for vintage fittings.

4. Electrics/heating - integrating key technologies
Now is a good time to replace worn out infrastructure and appliances. The ultimate lighting comes from that giant orb in the sky, so introduce windows and skylights where there were none, if more light is required.

Replace old incandescent bulbs with LEDs to save energy, and design lighting to make the space attractive. Avoid spotlights cut into the ceiling - they're simply holes through which heat will escape. Concrete, tile or stone 'sinks' in the form of floors or benches, when in the sun during the day, will release that warmth back into the space when the sun goes down.

The sun will also power your home through solar PV panels and, combined with the new technology of heat pump water heaters - a super-efficient replacement for the traditional electric water heater, you can reasonably expect your bill to reduce by up to three-quarters.

When you go shopping for whiteware, remember the Energy Star logo represents the top ten per cent in their category for energy efficiency.

5. Flooring
When it comes to flooring, there are many eco-choices. As well as reclaimed native timbers, modern options include bamboo or cork tiles - warm and comfortable underfoot. A wool carpet is pure luxury, fireproof, stain-proof and environmentally (and farmer) friendly, and carpet tiles and vinyl floors can be made from recycled materials.

6. Plumbing
Now's the time to reconfigure the plumbing, so that water can be conserved, or re-used. Rainwater collection tanks, wetback water heating, low-fl ow shower heads, dual flush toilets and the re-use of grey water in toilets - much can be achieved to lower your home's water use. If your existing water heater is a veteran and approaching its use-by date, swap it out with the aforementioned heat pump water heater before it floods your new renno.

Low cost hot water

This cracking little heat pump will knock two thirds off an average water heating bill.

Water heating typically makes up about 30-35 per cent of the average power bill so that's quite a saving.

The Aquarian 170L Retrofit Heat Pump Water Heater fits easily into the space your old hot water cylinder takes up, and will provide enough water for a family of five.

Find out more about the Aquarian 170L Retrofit Heat Pump Water Heater.

7. Re-face, don't replace
Worn out MDF cupboards can be removed and replaced with new materials, provided the structure of the framework is sound. Try marine standard plywood - it's water resistant, able to be stained, or painted, looks great and is highly durable. The same can be done for bench tops.

8. Use low VOC coatings
VOCs are solvents that are released into the air as paint dries. VOCs can cause headaches and dizziness. The long-term effects are less certain, but according to the U.S. Environmental Protection Agency, some VOCs are suspected carcinogens. Low VOC paint is practically odourless, 100% acrylic and splatter resistant.

9. Invest in quality
It sounds obvious, but one of the most sustainable things you can do is buy quality. Not only will it last for years, but it will look amazing for most of them. If you buy lots of cheap stuff, pretty soon you'll be living in a tatty, uninspiring environment that doesn't perform well.

10. Pay for it
If you have to borrow to pay for your renno, why not make use of institutions which specialise in loans for sustainable projects. The Prometheus finance company, for example, loans money for projects with proven sustainability credentials, and Kiwibank has a Sustainable Energy Loan.

This editorial series is made possible with funding from Energy Alternatives. To find out more about energy efficient products visit energyalternatives.co.nz

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