Owen McShane: Sustainable building code alive and well

Owen McShane

Structural engineer John Scarry suggests that developers won't let engineers design "sustainable" buildings because "all they want is the cheapest initial cost, because running costs don't come out of their pocket". [see link below]

This argument assumes that the people who buy these buildings do not care about running costs either, which is simply not true.

Unfortunately, Auckland's planners have strangled the supply of land which naturally drives up the cost of land for all uses. The same planners drive development into less desirable locations such as railway stations or other "transport nodes".

Understandably, developers seek to reduce construction costs because they are paying too much for their land, and must sell in tight markets.

But Mr Scarry is on firm ground when he says we should enable the construction of buildings which are energy-efficient, which place light demands on infrastructure and are able to produce their own energy.

I have been able to achieve this in my own small development of several dwellings on a 7ha lot in Northland, because the land supply is not strangled and the location is attractive to buyers.

Consequently, the development achieves Mr Scarry's "green" goals.

* The dwellings are energy-efficient because they are of light construction and well insulated.

* They are oriented to the north and have decent eaves which keep the sun out in summer but let it in during winter.

* The houses are only one room deep and hence easy to heat with sunlight and to cool by through ventilation.

* They all have solar water heating.

* The roofs collect rainwater and modern technology makes it safe and palatable.

* The roofs are made of tar-impregnated recycled paper.

* The interior uses timbers such as poplar, macrocarpa and Japanese cedar milled from recycled shelter belts.

* The decks and fences are made from treated poplar, also milled from overgrown shelter belt trees.

* Stormwater is managed through a system of ponds from which a windmill pumps the water to irrigate the extensive vegetable gardens.

* Waste-water feeds and irrigates native bush or sub-tropical gardens through evapo-transpiration fields.

We have covenanted 5 acres (2ha) of high-quality native bush and because there are no tree clearance regulations here, we have been able to plant more than 80,000 trees and plants on the property, thus promoting biodiversity unachievable in any inner-city development.

And yet John Scarry suggests we adopt an American system which encourages intensification of existing urban areas and "penalises the endless conversion of farmland to sprawling commercial and residential estates".

The fact is that multi-storey, high-density development makes it impossible to achieve what we have achieved in our "sprawling estate".

This land was not productive farmland. It had been allowed to revert to weeds and pests.

We now grow olives, grapes and truffles as well as vegetable gardens which make us self-sufficient in green produce. My broadband internet connection enables me to work on site.

My "commute" is a walk across the bridge over one of the ponds.

We have a shortage of urban land and a surplus of rural land. Why strangle one to protect the other?

* Owen McShane is a resource management consultant.