Q: When it comes to sustainability in building what are you most passionate about? 

SD: I’m passionate about passive solar design and implementing sustainability practices early on in the design process. Energy conservationists are always looking at the star rating but in the end those are just numbers. A closed box without windows is the best outcome for energy efficiency but it’s unliveable. By opening up our homes to the outdoors it takes people one step closer towards a personal connection with nature; that’s when people appreciate and start to respect the environment.

Q: Our climate is getting warmer, what can we do to mitigate heat absorption in a home? 

SD: When it comes to heat regulation land sizes today don’t offer much space for greenery. Plants act to lower the temperature of a space, which is key with our warmer climate. Where it isn’t possible to increase land size we should continue to look for heat reducing measures, such as replacing dark coloured roofs and driveways with lighter tones. These solutions help individual homeowners and the broader community. 

Some years back, Clarendon Homes conducted research and found roof spaces with black tiles could get as hot as 90°C in summer. Central cooling is located in the roof space with little insulation, so it requires a huge amount of energy to decrease the ambient temperature to around 20°C, which is comfortable for most homes. We made cooler roof spaces by incorporating Bluescope’s Thermatech® technology. That dropped the roof’s attic temperature to 45°C, which made the airconditioning 25 per cent more efficient. 
At the other extreme, I believe future planning needs to look towards mitigating the effects of Australia’s increasing flood events. A solution may be to use more porous ground materials rather than favouring concrete and asphalt to allow water to soak into the ground. 

Q: Do you think COVID-19 will influence house designs to improve occupant health and wellbeing?

SD: COVID-19 has shown us that our homes are not properly equipped to allow us to work from home without incurring a large energy bill. If we are to look into working from home as a long-term solution to health concerns, then we will need to focus more on renewable energy supply and storage. 

Whether inside the home or in public spaces, we need to consider touchless systems, such as taps, as a key inclusion moving forward. These kinds of systems have intelligent wiring and can work hand-in-hand with sustainability efforts. With current taps, leakage is an often unnoticed or unresolved occurrence that leads to water wastage, but there’s nothing stopping manufacturers from adding extra intelligence to these touchless systems to detect leaks with the grounding technology already in place. 

Public spaces and materials we use are more than likely to change to allow for more space – which I believe can be filled with greenery – and, now that we know metal can harbour this particular virus more than other surface options, alternative materials may be a further consideration. 

Finally, intergenerational designs may influence our housing in the future. COVID-19 isolated many of our elderly residents so options for them to live close by or live in our homes for their safety, health and wellbeing may be considered more. All of these aspects go hand in hand with sustainability. 

Q: What are some obstacles that building professionals face when attempting to design and build sustainable housing? 

SD: One obstacle is new products and their cost because our supply chains are long and we don’t manufacture everything in Australia. I would like to see more local products being used to encourage the local economy. Products such as double or triple glazing are great for insulating a home but can be expensive; I instead design houses with products that aren’t as costly.

I believe people should be better educated in sustainable housing, and convincing them to implement certain aspects can be a challenge for industry professionals. What has helped me with clients is being able to show them through a sustainable development because they can then see its true value. That’s why I love sustainable housing concepts because private homes are open to the public which could never be seen otherwise. It would be great if builders and designers encouraged their clients to open up their eco-friendly homes for others to experience and see its benefits.

Q: Have you seen much innovation in sustainable products in recent years?

SD: We are continuing to improve energy efficiency and the Building Code of Australia (BCA) has air-tight requirements which is something very critical. As we keep making our building airtight then ventilation becomes a problem. Opening a window helps but is less desirable when it’s cold. Heat recovery ventilation systems are needed then.

When it comes to products and energy efficiency it’s important to also consider how much energy has gone into making materials. If you look at energy required for a house, it’s needed during construction and during everyday use. Your energy consumption can be reduced by solar panels and other products, making it more efficient, but there is a lot of energy that goes into making those materials.

The BCA now allows timber buildings up 25 metres to encourage materials that are not as energy intensive as steel and concrete. So, industry can look at using more timber or using bricks which use less energy in local production, or use renewable energy to make bricks – even the manufacturers are looking at that.

We’re also hearing talk about solar cars being able to act as energy storage batteries because batteries still haven’t come to a commercial level yet. From my perspective, there are some of the innovations that are happening and it’s because of the trends that the industry is moving towards. 

Q: At what point should eco-friendly additions be implemented into a home?

SD: In the early stages of design people normally think about the functionality of a home and don’t think about how they can modify it to be more sustainable – until after it’s been built. But it should be the other way around. Add-ons, such as technology, aren’t as effective without a fundamentally good design; rather they help to enhance and further its sustainable attributes. When the two work together that’s when maximum performance and minimum cost can be achieved.

I’ve just finished working on a renovation of a 1920s home in a heritage conservation area. My approach wasn’t to segregate the components but to look for ways to make the house better as a whole. I combined the new house with a link so both the old and new sections were joined without touching.

It was a challenge to convince the client that this was the best way to go because they usually listen to what other people have done. The problem with that is occasionally they forget that the work they’re referring to was done years ago when there were different rules and regulations in place.

So, as professionals I believe we should stand our ground about what is relevant now and how we can achieve the best outcome for our clients. They may have trouble seeing this without the visualisation component but the key is to persist with them gently and firmly. In particular, my client was happy about the sustainability and the social aspects. His mother could never come and stay in their house because of the level differences, so the new extension was for her to access. It’s all about how the family lives in the house – that’s how I view sustainability.