KEY POINTS:
Truly affordable houses are cheap to run, not just cheap to buy.
When the Prime Minister outlined her Government's plans to increase the supply of affordable housing, she missed an opportunity to explicitly link this initiative with another of the Government's key policy planks: sustainability.
As she herself said earlier: "One can't talk about innovation and infrastructure without linking both to the need for New Zealand to be more sustainable."
The mistake made by many people when considering the issue of affordable housing is restricting the parameters of the debate to the price charged for a house. Yet with houses, as with cars, indeed with any piece of equipment, the initial capital outlay is only part of the cost of ownership: running costs throughout the asset's lifespan are also a major contributor.
But while most car owners know the costs of running a car, particularly with petrol prices regularly hitting the headlines, few people have any idea of just how much energy and water their home uses. Even fewer could tell you how warm or cool their homes are.
They just turn up the heat in winter, pay their fuel bills, and mop up the condensation.
To put it another way, the average New Zealand house is dear to run - and many being built today show no signs of improving on our dismal performance in this regard.
Last year Beacon Pathway commissioned the National Value Case for Sustainable Housing Innovations, an in-depth, robust, cost-benefit analysis of the value of improved housing sustainability - considering both new and existing homes.
This study rigorously assessed six areas in which higher standards and better performance would mean significant social and economic gains for individual homeowners, and for the nation as a whole - insulation, space heating, lighting, water heating, low-flow water devices, and water metering and pricing.
A clear and practical demonstration of the potential benefits was provided by Beacon Pathway's first live research project - the Waitakere NOW Home, which over a two-year trial period used 33 per cent less energy and 40 per cent less water than an average home. This was not a design dreamed up in the laboratory - all technology, materials and design methods are readily available, and the house was built for just $220,000.
Reducing energy requirements - and therefore energy costs - by this order of magnitude generates a significant increase in household disposable income, which could easily go towards repaying the mortgage.
The National Value Case also highlights the benefits of improving the sustainability of existing homes in the six areas mentioned. It could mean national annual energy savings of 22 petajoules (enough to power more than 500,000 homes), with associated reductions in CO2 emissions, and reduced strain on New Zealand's transmission network and other key infrastructure.
It involved direct water savings of 81 litres per person per day, or about 130 million cubic metres a year, reducing household costs and environmental effects and effectively increasing the lifespan of the infrastructure in place. All up, it means a direct private economic gain to households of $2 billion within 10 years.
There are some other easily quantified individual economic benefits that follow on from implementing sustainable building initiatives.
New Zealand houses are generally cold (an average 6C below World Health Organisation-recommended minimum temperatures in winter), damp (45 per cent of all New Zealand homes are mouldy), and hard to heat (many are poorly insulated. And a significant proportion use unflued gas heaters as a major source of heating).
These factors contribute to our high asthma rate and to an excess winter mortality rate (the number of additional deaths occurring in winter months compared with non-winter months) of 1600, unique among OECD countries.
Designing sustainable housing clearly has the potential to reduce not only the power bill and water rates, but also household medical expenses and lost work time.
For the economy as a whole, the true benefit of sustainable homes is likewise in reduced spending on health and increased productivity, as much as it is in reduced energy consumption and CO2 emissions.
Although there is a clear case for sustainable housing practices on the grounds of individual economic benefit, it does require long-term thinking. The benefits are accrued over the lifetime of the house and its occupants. But the greater part of the costs are borne up-front.
And the benefits that flow to the economy as a whole make it worth the Government investing in incentives and other initiatives that will change the behaviour of developers, builders and house buyers. Politicians on both sides of the House are talking a lot about sustainability; many are also demonstrating a strong commitment to walking the walk, as well as talking the talk.
Initiatives such as higher energy-efficiency standards in the Building Code, the Home Energy Rating Scheme, and the Sustainable Households programme are demonstrations of the Government's commitment to housing sustainability.
But these measures are just scratching the surface, and until the Prime Minister makes the connection between sustainable housing and affordable housing, real progress in this area simply won't be possible.
It's high time the Government looked at the long-term economic, social and environmental advantages of developing a sustainable housing stock, and what it can do to facilitate that development.
* Nick Collins is the general manager of Beacon Pathway, a research consortium working on affordable, attractive ways to make NZ homes more sustainable.
