Two recent works in Melbourne by Kennedy Nolan with Finding Infinity and a UNSW project underway with Dubbo City illustrate what can be achieved—optimising thermal comfort, savings in operations, and the momentum required.

In changing climates, what does thermal design optimisation to improve comfort, efficiency and affordability look like? Can you explain the concept?

DEO PRASAD, Scientia Professor at UNSW: Base knowledge on this is widely available—the choice of appropriate materials, orientation around prevailing wind, sun and shade structures, use of thermal mass and insulation, appropriate glazing and shading systems and infiltration controls. Every house needs to be designed to high thermal control requirements including existing building stock. So, it is not difficult to imagine the indoor temperatures in poor thermal designed buildings. In some urban areas poor design and planning outcomes have exasperated the problem.

VICTORIA REEVES, Director of Architecture at Kennedy Nolan: We are partly in this situation because we’ve over consumed in the design and construction of buildings. The challenge now is how we can provide comfort and accommodation with the least resources.

How do we address this? Are sustainability and housing affordability at odds? Specifically, compromised comfort ahead of other necessities.

ROSS HARDING, Founder of Finding Infinity: For the same budget as standard housing, we can create and transform buildings to feel great thermally without the need for active heating and cooling.

DEO PRASAD: If buildings are airconditioned it translates to high energy bills—this impacts affordability and wellbeing. A well-designed home is essential for thermal comfort and at the same time delivers on lower energy bills and much lower carbon. Solar photovoltaics is the cheapest option as it can be linked to heating and cooling systems as well as all other net metering offsets. Latest data shows that around 4.2 million houses have rooftop solar (among the highest per capita in the world). The government’s battery subsidy now supports better and cheaper energy bills and in many cases no energy bills. The materials we select, what the embedded carbon is, and what can be done with it after the life of the building hold equal importance—in other words re-use and recyclability.

VICTORIA REEVES: The construction industry, authorities and the market have now embedded high-performance envelopes into most of our baseline medium and high-density housing. Fortunately, the normalisation of these standards makes them more affordable and certainly result in lower operating and maintenance costs.

ROSS HARDING: Every project has an opportunity to function better with the same budget. Running costs are a gap in the industry. We find that most projects can deliver zero running costs, on budget with significantly less environmental impact, but it needs to be considered from the early phases of a design. The cost-effective stuff is not an add on. Comfort and running costs are directly proportional, poor passive design and poor comfort results in high running costs.

VICTORIA REEVES: What isn’t so certain is the broader infrastructure that ensures that homes, buildings and communities can thrive—accessible public open space, active streets with canopy planting to reduce heat, connection to public transport and other services.

Above: Balam Balam Place by Kennedy Nolan with Finding Infinity and Openwork incorporates 100% roof runoff to the tanks and maximum on-site permeation of storm water—a critical move on projects to lower the temperatures in our cities, and to repair soil ecology and waterways. No active heating and cooling to the circulation spaces which allow them to be much more permeable and inviting and reduces the area for energy intensive heating and cooling by 35%. Photos: Derek Swalwell.

Is there a project, built work (or on the drawing board) that illustrates this?

VICTORIA REEVES: Wilam Ngarrang Retrofit in Melbourne is a good example.

ROSS HARDING: Only 30% of the construction budget was for environmental upgrades, but we estimated this would result in bills of A$1,100 per apartment annually to around $50 per apartment. We were able to integrate airtightness, insulation, HRV, heat pumps and efficient air conditioning, a large solar array, rainwater collection and composting on site. The design team were incredibly aligned on using the budget effectively as we knew that any increase in budget would need to result in an increase to final rents.

VICTORIA REEVES: With our public projects we have achieved a lot but not everything survives the inevitable bureaucracy and constraints or the impairments of our construction industry.

What are the challenges, impairments? Can you elaborate?

ROSS HARDING: The industry has a minimum compliance mentality, and defaults to the worst thing you’re legally allowed to build—the industry attitude is a challenge. We see it more like there are lots of opportunities to go above and beyond minimum compliance in construction to make buildings better, we see this as the responsibility of developers, architects and builders.

What does the sector need to address to provide better climate outcomes and help foster an ecological behaviour?

VICTORIA REEVES: I am interested in the idea of an ecological behaviour. If we could be more aware of our place within our ecology, the impact of our actions (environmentally, socially, economically) then it might place us in better stead. I’m optimistic that the built fabric—the design of our housing and other developments and our streets and how we operate our buildings, can support this connection to place and to each other. Balam Balam Place was designed and delivered alongside friends and energising collaborators—Finding Infinity and Openwork. The great wonder of this project is the way it operates. Managed by These Are the Projects We Do Together, this project does seem to have its own ecosystem of sorts.

DEO PRASAD: To provide better climate outcomes, in addition to renewable energy integration, buildings which differ in occupancy across times of the day, week, and year can be programmed to meet varying needs—and extreme weather days. The High-Performance Architecture group at UNSW is currently working with Dubbo City, the Federal Government and industry partners to test an Ai enabled plug-in which can interrogate the upcoming weather (including extremes) and pre-prepare the building systems to deliver uninterrupted comfort, low energy use and carbon impacts, while managing solar and battery as well as demand-side functions of the building.

Above: The Wilam Ngarrang Retrofit project by Kennedy Nolan with Finding Infinity sets an example of the environmental, social, and financial benefits of retrofitting existing apartment blocks in Melbourne’s inner city. Photos: Eve Wilson.

With affordability in mind, what are your thoughts on build to rent?

VICTORIA REEVES: As I understand it, build to rent’s heritage is in American cities, in areas often lacking in public infrastructure. Australia needs to pave its own way in this model, and it should be outward looking, integrated to the street and communities they sit within. And they should have a mandated affordable housing contribution.

DEO PRASAD: The build-to-rent sector should try and overcome the split incentives of who builds, who pays and emits, and who occupies what may be expensive to run and uncomfortable buildings. Market failures often imply cheaper buildings but poorly performing ones. Incentives may be another lever for governments to push the retrofit sector to improve existing building stock.

ROSS HARDING: It’s an advantage to be able to integrate the running costs into the overarching development and business model, this unlocks more environmental opportunities. But we also have our scepticism about the build-to-rent model and whether this is just passing on a higher rent outcome for future users. It really depends on the project and whether it’s seeking affordability or if it’s just a different form of an expensive product—is the operational benefit getting passed on to the user financially?

How can architecture and design make housing affordability a reality that is sustainable and affordable?

ROSS HARDING:What needs to be done isn’t that complicated—less glazing, good shading, more insulation, more solar, heat pumps, no gas, efficient water fixtures, collect and re-use rainwater, prioritise circular, zero carbon materials (avoid concrete), design for zero waste.

DEO PRASAD: The sector including designers, developers, owners, occupants and all levels of government need to commit to improving the building stock performance for health, wellbeing, affordability and environmental outcomes. Changing climate with poor planning outcomes show urban heat islands become a significant problem too—greenery is much cooler as expected.

VICTORIA REEVES: Architecture and design can’t do it by itself, making affordable sustainable housing is expensive and government needs to contribute to that. We can help by making sure that the supply is of a quality that can serve the resident and the city well for many years to come. There is a lot of talk about supply numbers (big ones!) at the moment and not much conversation about quality, we don’t want to be left with a disastrous legacy in this rush for supply.

Main image: Balam Balam Place by Kennedy Nolan. Photos: Derek Swalwell.

Emma Adams

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