Five architectural solutions to boost energy-efficient housing
Sunday, 17 May 2026
Rising costs are front of mind for most, but putting some basic architectural solutions to use when building would boost the number of energy-efficient homes.
A combination of the fuel crisis prompted by the Middle East war, and another increase in electricity prices heading into winter has left people looking for cost-cutting solutions, now and for the future.
Building more sustainable and energy efficient homes would help, but the drive towards intensification has thrown up concerns around the quality of new builds.
In a city like Auckland there are large areas of new build terraced townhouses in rows, but there seems to be a limited market for them, architect Scott Cracknell says.
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Cracknell, who is a principal at Context Architects, says that’s because people are often choosing to buy existing stock because of a perceived lack of amenity in new builds.
But density done in the right way, with good environmental outcomes can be part of the solution to high-cost urban sprawl, and can also mitigate the energy concerns of households, he says.
Here are some straightforward architectural solutions he suggests to help achieve those goals.
A bit of space is important
There’s some interesting housing being built in Auckland under the Unitary Plan, but in many townhouse developments the space required has been reduced down too much, and the lots are too tight, he says.
“Developers usually work with a profit motivation, and want to maximise the yields on a site. But maxing out land usage on individual lots can undermine wider environmental performance over the short and long-term.”
Judicious, controlled land use by combining two or three lots side-by-side for example can achieve the same level of intensification with healthier, less carbon intensive homes, he says.
“A high quality development will have room for light, for privacy, and for green spaces.”
The narrowness of modern townhouses is also the enemy of natural ventilation, he adds. In contrast, wider floorplates, with windows either side, allow for cross ventilation.
Don’t forget about trees
Cracknell says that counter-intuitive as it may sound, more urban homes need more urban nature, and allowing room for trees and planting will make a big difference.
Street trees and the greening of the city’s stream network can create public amenity that also reduces carbon and flood risk, he says.
That’s because the more hard, impermeable surfaces there are, the less spongy the ground is, and the more flooding there will be, but plants help to mitigate the risk.
“If there is more tree planting, along with attenuation tanks to slow storm water down and get it into the streams, the better it is in every way for homes, and for the city.
Street trees and greenery have another benefit, he says. “For many new build homes, over-heating through summer is more of an issue than cold and damp through winter.
“So trees can play a key role in in-home temperature regulation – and also improve the overall carbon performance of cities.”
He believes the retention and planting of trees in new build developments should be financially incentivised to make it a viable development choice.
The value of the humble eave
The problem of overheating was made worse by the current trend for large windows, covering much bigger areas than traditionally the case, Cracknell says.
“They make homes bake, but the shading defences used in the past, such as eaves or the canopies seen over windows in villas and bungalows, have been cast aside.
“Eaves are often sacrificed due to height to boundary limitations as developers seek to maximise floor footprint, and no longer provide adequate levels of shading.”
While he is an advocate for the return of the eave, he recognises the situation is different when it comes to multi-level and multi-unit buildings.
“It is still possible to design a high quality building with good shading, but it requires careful thinking around the way the space is planned out to get good amenity and outlook rather than just decoration.”
Enable natural ventilation
For Cracknell, another problem with the prevailing approach to windows in new builds is that it impacts on the ventilation and air quality of homes.
Side windows are often sacrificed which designs out the ability to achieve cross ventilation and naturally regulate the home’s thermal environment, he says.
“Window restrictor stays reduce the level of ventilation a home can get, and the way ventilation is calculated in builds means homes end up with a small amount of ventilation that is not functional.”
“Ventilation requirements are being reviewed now, and a shift around that and window joinery will make a difference in avoiding an over-reliance on energy-hungry mechanical ventilation.”
There are also some basic things that can be done to help, such as putting slats on windows and using roller blinds, although it comes down to cost and finding things that fit together, he says.
“The aim of all this should be to create just the right comfort levels that preclude owners or tenants from having to use and pay for energy to warm up or cool down their new home.”
Get help in the brave, new world of granny flats
Earlier this year legislation scrapping the requirement for resource and building consents for structures of 70sqm or less, or granny flats, came into force. The change is intended to make it easier to utilise existing land to build simpler, more affordable homes.
Cracknell says granny flats are generally going to be more applicable in outer suburbs of big cities, or in rural towns where sections are bigger.
But the way the intensification of these spaces is treated is important, and getting the right balance between environmental, economic and architectural imperatives should be the goal, he says.
“Many people now think building a granny flat is easier than it actually is. You don’t need a consent, but there’s still lots that needs to be done to work through the process, and get the best design outcome.
“People will need help to navigate their way through the process, and for a certain size dwelling there are only a certain number of ways you can build. Some things just work better than others.”
For that reason, Context is supporting a University of Auckland-led, BRANZ-funded study into how the granny flat legislation can be best put to use to enable uptake faster, he says.
“We aim to create an open source pool of robust, repeatable cost- and environmentally-efficient architectural designs and plans that can be delivered with a lighter touch than traditional construction, and that people can work through with their LBP teams.”