Welcome to Mullum Creek Estate in Donvale, Victoria, where all houses have at least a 7.5 NaTHERS energy efficiency rating, are made from sustainably-sourced materials and prohibit opaque fences, in order to encourage neighbourly interaction.

It’s one of several progressive residential communities or estates seriously raising the bar on sustainability through ambitious design guidelines or controls.

These limitations on the design of new homes are typically put in place by a developer or council to deliver desired outcomes for new residential subdivisions.

Environmental considerations may feature, such as requirements around keeping trees or vegetation, but the focus is typically on aesthetics. That is, making sure there’s a level of cohesion maintained throughout the community through a specified colour scheme, setbacks and driveway sizes.

Now some progressive estates are using design controls to lay down the law on a high ESD standard. And it’s not proving a deterrent for buyers, with lots in many of these estates selling like hotcakes.  

Maxa Design director and principal designer Sven Maxa has designed one home on the Mullum Creek Estate, a Passive House home made from rammed earth, and is also on the Design Review Committee for the estate. He says the estate has an array of progressive design requirements for building environmentally sensitive homes.

These design guidelines go well beyond specifying colour palates and setbacks: all homes are required to be built out of sustainable materials, such as sustainably-sourced timber, and have storage capacity for 20,000 litres of rainwater for use in the home and in the garden.

“They have invested a huge amount of money in researching construction methodology and materiality to support the sustainability outcome of the buildings,” Maxa says.

While the design rules might add a bit of upfront cost for prospective residents, Maxa says it will save people money in the long run through lower bills, and likely improve the value of all the properties over the long term.

The design requirements are also looking to build community resilience and cohesion by prohibiting opaque fences to encourage neighbours to get to know one another.

“It’s building a community is what it is doing, where everyone is like-minded. They will be out there trading fruit and veg and sharing it with their neighbours.

“I don’t know why more estates don’t do it.”

Setting the bar high also didn’t deter buyers, with all 56 sites sold out and half of those gone within a year of launching in mid-2013.

More than a colour scheme

Another greenfield community pushing the envelope on ESD requirements is The Cape at Cape Paterson on Victoria’s Bass Coast.

The Cape director Brendan Condon says that it’s no secret that having good controls in a development and well considered guidelines drive better outcomes across the whole estate.

“A lot of conventional, high quality estates have reasonably comprehensive guidelines, but they are generally around aesthetics and architectural style.”

At The Cape, he wanted to “drill down into the laws of physics” in its design guidelines. 

The design guidelines for the project and the brief for the builders mandates a minimum of 7.5 star NatHERS, at least 2.5 kilowatts of solar PV, and an energy-efficient fitout and appliances.

All homes are also to be fitted with a minimum 10,000-litre rainwater tank for garden and toilet flushing, 15 amp electric vehicle charge points and an electrical system that is solar storage battery-ready.

Low and zero VOC paints, and low-carbon construction materials such as rammed earth, radial sawn timber and Weathertex are also being used.

The guidelines have also been extended to take into account resilience and lower running costs, Condon says.

“We did this so we can hit operational carbon neutrality for the estate and help provide an example of how Australia’s housing sector can move forward.”

The assured high standard of sustainability appears to be attracting buyers, with over 33 per cent of the latest lot release gone in just three days. “It’s moving quickly, it’s powering on.”

He says that there’s been minimal pushback on the design guidelines. In fact, most people are excited by the prospect of a well-considered standard of housing that stays at a comfortable temperature in both summer and winter.

“There’s also this nice open fenced feel to the place, and people are enjoying that sort of socially positive design element as well – no front fences, lots of walking tracks and pocket parks.”

For Condon, the optimal outcome is for a higher minimum NatHERS standard and other bolstered sustainability requirements to make it into the national building code and other nation or state-wide regulations.

A high minimum NatHERS rating looks set to happen in September 2022, with the minimum to be raised from 6 to 7. Condon says that requirements around electric, carbon neutral housing are also on the table.

But he believes that to drive the national transition to more sustainable housing, “we do need ethical, progressive developer stepping above the minimum to show it is economically feasible and possible, it gives confidence that it’s achievable.”

“I’m hoping we’ll see a raft of other developments going this way. We are really at an inflection point.” 

Brave builders proving 7.5 NaTHERS isn’t that hard

Leigh Hall Sullivan is the selling agent at Salt Torquay, on Victoria’s coast west of Melbourne, another estate pushing boundaries through its design guidelines, and says that the lots have nearly sold out.

The lots are part of a One Planet Living Community and all homes must have at least a 7.5 NaTHERS standard – something Hall Sullivan says initially spooked builders that would speak to the design committee and decide “it’s too hard to build here”.

But the floodgates opened when mainstream builder JG King built the first one and proved it wasn’t that hard or expensive: it was really just a matter of having north facing windows, thoughtful orientation and better insulation. 

Once the first builder proved it wasn’t that hard, sales shot up, and local builders got in on the action. “We’ve sold 80 per cent in the last two years.”

He says builders are able to produce homes at above the standard energy efficiency rating at the same cost as a standard build, but “still not quite as cheap as super cheap, mass produced builder.”

Hall Sullivan says that the developer, Barwon Water, Victoria’s main regional urban water corporation, opted for the high energy efficiency rating “just to show that you can do it and it’s not that more expensive.”

“And once you’ve held on the home for five years, it’s paid for itself, that’s the difference in a 6 star to a 7.5 star home.

“It’s a lot cheaper to live in moving forward.”

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  1. Sustainability is not just about passive solar design. It also includes rainwater capture, wastewater re-use, solar hot water and solar power systems. The Nathers rating scheme must be changed to include these features before we can call a home truly sustainable.