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Andrea Blackmore
Do energy and water efficient homes cost more?
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Here’s the latest Beacon Blog from Verney Ryan…DSC_8430a reduced

I noticed an article in the Press recently that amazed me: Canterbury architects claimed that building new homes to be energy and water efficient would add $15,000 to the cost of home building ( ).

The New Zealand Institute of Architects  (NZIA) in Canterbury was challenging proposed new rules in the Christchurch City Council’s district plan that would require new homes to be built to a minimum Homestar 6 rating.  They claim this would add unnecessary cost to the building process.  They say the Building Code doesn’t require these levels of performance so why should Christchurch City Council?

I think this is wrong on so many levels, it’s hard to know where to start!

Let’s start with the accusation that building a new home to reach a Homestar 6 rating would make it unaffordable.  (Of course this refers only to affordability of purchase price – there’s affordability of operation but let’s set that aside and come back to it.)

It is true that reaching Homestar 6 will add some additional cost to the build over a similar design.   Jasmax calculates it would add a little under $6,500, or just over 2% to a typical Auckland house (  It’s important to remember that this isn’t fixed – there is a range of ways to reach the Homestar requirements  and it’s not all about expensive kit!  Good solar orientation, compact design, and simple resource efficiency need not cost more especially if the house design incorporates these from the beginning rather than just adapting existing designs.  There are mandatory minimum requirements for energy and water efficiency but other than that there is no set way to achieve your particular target. ( )

I recently assessed house designs for one of the new Special Housing Areas in Auckland to see how they could cost effectively meet Homestar 6 requirements.  Some of my recommendations added cost to the build (such as upgrading to double glazing – which just makes good sense and adds other benefits beyond energy saving), but some were a case of ticking off low cost and easily achieved credits.  These included WELS rated plumbing fixtures, increased insulation, better construction waste management. Actually, reaching Homestar 6 is not that difficult and my recommendation to those in Special Housing Areas is to aim for the higher Homestar 7 rating and build real value into these houses.

The big problem with the NZIA’S argument is that it focuses on upfront affordability and ignores the ongoing operation of the house.  Yet when you think about it, a new owner will be paying the power bills, gas bills and water bills for many years to come, covering rising prices and increased charges.  Building with an eye to reducing energy and water use is just common sense and will pay off for many years to come.

Beacon’s demonstration homes reflect the savings that can be made:  the Waitakere NOW Home saved 33% on energy compared to other houses in the area, and 40% less water than the average in the area.  With good design, orientation and higher than Building Code minimum insulation levels (shock! horror!), the house needed no additional heating, saving on power bills and the costs of installing a heating device.  The NZHF HomeSmart Home incorporated water efficiency measures that reduced the family’s water use to 117 litres per person per day, compared to the average in the Waitakere area of 165 litres per person per day.  Water is metered and paid for separately in Auckland, so using less water had a direct financial benefit for the family of $570 a year.

To me, building and designing with an eye to reducing ongoing costs in the future is a definite value add for clients.  Even more so if you take into account the non financial benefits of warmer drier healthier more efficient homes.

Beacon’s (and other) research highlights wide ranging benefits to homeowners that go beyond traditional cost benefit analysis.  In all our demonstration projects, we have talked to the homeowners involved and the picture is clear; improving your home performance extends benefits beyond cost to social, health, mental health and family benefits.

Our families report increased warmth throughout the house leading to improved physical health, with fewer reported colds and flu.  Especially important were reports of the effects of a healthier environment for their children – less asthma, less medication, fewer days off school.   Strikingly, the participants report happier, more relaxed families enjoying better relationships and socialising.

“We are happy here, which flows through to everything else.  Everything has been better since being here”

Joe and Hayley, Waitakere NOW Home

“No one had been sick since arriving in the house and we no longer needed our asthma inhalers”

HomeSmart Home family

 “Being warmer has made us happier; we were on edge before, and cold, it was a nightmare, this has taken a weight off us”

Papakowhai family

So there are perks aplenty for lucky homeowners of houses designed for the sort of performance that Homestar 6 brings.

My last beef with the NZIA position is their criticism that Christchurch City Council shouldn’t be requiring more than the Building Code requires.  Homes built strictly according to the standards of the Building Act might be lucky to scrape by with only a Homestar 4 rating.  And that’s because the Building Code only mandates minimum levels of performance (the key is in the wording… minimum –  or should that be bare minimum?).  Thought of another way, the Building Code is really setting out a way of ‘building one step better than breaking the law’ – do we really want to aspire to that?  Do architects?  To achieve the benefits of a warmer, drier healthier home, you need to exceed those minimums, and Homestar provides a structure to help you do it.

Christchurch City Council, quite rightly, sees the opportunity to influence its housing stock to perform better for the residents of the future, with spin offs for local infrastructure requirements, reduced demand on energy and water, and reduced costs at both local and national level (see Beacon’s National Value Case for Sustainable Housing Innovations ).

In my opinion that’s just being farsighted!

Finally I should point out that some of my best friends are architects – and some of them seem a little cheesed off at the NZIA taking this stance.  Let’s hope the good architects (and designers) out there can assist with a culture change that enables us to build Christchurch back better – no one wants a ‘minimum standard’ city, do they?

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