The early years of the twenty-first century saw a major shift, away from objects and towards people. This was most evident in architecture, where ideas shifted from sustainable buildings to sustaining people. A prime example was the focus on human ‘wellness’ within the Green Star accreditation system.

This shift is evident in a study of residential thermal comfort. In the early days of the environmental movement, people relied on ‘moral encouragement’, saving the world through good buildings everyone would want. Passive solar was the central approach. If houses faced the sun, all would be well.

Passive houses require residents to be ‘active' – the house changes through the diurnal and seasonal changes – and accept a wide range of temperatures, wearing extra woollens in winter and less in summer, all to lower energy demand and avoid air conditioning (AC).

But they weren’t. Too many houses were already too bad for passive solar to fix, and no one was home to pull the drapes on winter evenings or lower the blinds on hot days. A great idea that, in practice, didn’t shift the dial.

The failure highlighted the need to focus on occupants' real needs. Critically, many people, including the elderly, young, and infirm, have a far lower tolerance for thermal variations common in passive solar, ever more critical with a warming planet. Passive solar doesn’t work for them; they absolutely need more accurately controlled thermal comfort. Hence the need for the dreaded AC.

So sustainable design changes from passive to active. Houses, old or new, need to be super-insulated, with double-glazed windows and better shading, so that an AC unit, powered by photovoltaics on the roof, is viable. The occupants will then have better thermal comfort, avoid fossil fuels, and use less, or no, energy.

The passive-design dinosaurs of the first age were spitting chips, but sustainable technology moved on to ensure better human comfort with less carbon, even if that means a reverse-on-reverse cycle.

This change in thinking highlights a third shift. Sustainability is no longer enough, just finding alternatives to keep the world as it is. It’s now about enhancement to improve people's lives. We now talk about enhanced design making lives better, particularly for those in the third world.

We are moving from merely improving buildings to making them carbon neutral (net zero), or better, carbon positive. And more broadly, it demands a rethink of how we frame every design:

Inequality is a great scourge now; design must rebalance it at every opportunity.
The solution may be to reduce, not increase – everything.
It’s often better to keep a building and improve it than to build a new one.
Indigenous practices are sustainable design; we must learn how to apply them.
It’s not designing the object, but creating the result. For instance, it's not sustainable cars, but sustainable travel.
Landscapes can be productive and provide carbon sequestration.
Food must be rethought to be equitable: lower carbon and higher value to end famines.

That’s a lot to think about as the design professions gather for the Sustainability Summit.

The Sustainability Summit is on 12 November 2026 at the Fullerton Hotel in Sydney. Click here to learn more about the topics or to reserve your seat.

Tone Wheeler

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