Imagine… a home that is naturally warm in winter, cool in summer and uses clean energy from the panels on the roof (with a couple of batteries) to heat your water and power the house when the sun doesn’t shine. Not only are there no ongoing costs to you, no carbon emissions are created in the process. Your comfortable, healthy home is contributing to the emission reduction targets that Australia is making as a responsible international citizen in response to the IPCC Report’s Code Red Alert.
Many are enjoying these great benefits right now, and many think the Australia’s building code should require this of all new homes and major renovations so that they can be enjoyed by everyone.
While this might seem simple, there are various nuances and complexities that arise. Such as what does “zero emissions" housing actually mean? And how does it differ from “net zero emissions” or even "zero or net zero energy" housing? And what is the difference between “embodied” and "operational” emissions? And does any of this really matter?
These terms are important, and so too are the concepts behind them and the future we can create if we approach them creatively. Importantly, they represent some of the easiest to achieve, shovel ready ways to reduce emissions in Australia – with significant positive social impacts of better homes for all.
Let’s start with the easy bit - what is the difference between emissions and energy? A lot, if you are getting your energy from fossil fuels (coal or gas) which are high in emissions. Very little if the energy is produced by renewable resources with no emissions. However, it is important to move our focus onto the emissions we are creating in our built environments, as this is what creates a major impact on climate.
So, what is the difference between “zero” and “net zero”? Zero emissions simply means that no emissions are created. Full stop. Net zero means that some emissions are created, but they are offset by removing emissions from elsewhere in the system. This can be achieved by exporting zero emissions energy into the grid when it is not being used by you, while you pull emitting power out when need to. Or by pulling carbon out of the air by planting trees or carbon sequestration in soil or other means. Problems can arise when people game these offsets or create dubious schemes that don’t remove the emissions stated.
“Embodied" emissions are those relating to the construction of the home, while “operational" emissions relate to those created when the house is being lived in. Traditional concrete, steel and aluminium have high embodied energy. Timber homes (from well managed forests) can have very few. There is a lot of work being done now to reduce the emissions of all materials, especially those with high emissions. This is where many jobs could emerge in Australia, by making the most of our abundant solar and wind renewable energy to develop green manufacturing. Embodied energy is in its infancy in Australia now, as we have not had to account for it until now and our general understanding of its impacts are low. However, ideas that will help reduce these emissions immediately, include valuing and keeping existing buildings with their extant embodied energy, building less, and building smaller.
Does any of this matter? Yes, it does, but it is complex and nuanced… For a well-designed efficient home sitting on a block with no overshadowing, plenty of roof space and battery storage capacity – zero emissions should be relatively easy to achieve. For a home that has nowhere to locate solar panels, or a heritage home that is not allowed to put solar panels on its roof, or an apartment block that has needs larger than the collection area, or other similar cases, it is not possible to regulate for zero emissions now. While the owners can purchase 100% green energy, they cannot be required to do so. Until the energy from the grid is completely emissions free, we need to work out the most consistent way to accommodate the idea of net zero emissions in our regulations.
To begin with, the heavy lifting of reducing emissions should be done in the initial design stages by making our homes smaller, more energy efficient and totally electric. Then, they can make an appropriate contribution to the emissions reductions our society needs to make if we want to hold global warming to anywhere near 1.5˚C.
So why should anyone other than architects, engineers, builders, and other built environment professionals care about this?
As people who live in homes, we should all care about how they are built as we are the ones who must deal with the outcomes. Many realised how uncomfortable our homes were as we spent a lot of time in them during lockdown, and either suffered the cold or spent too much money keeping them warm. While those who own, build new or renovate single homes might have more interest and control over what happens, those who do not have control over the building process are very reliant on what the building codes require. This includes apartment owners, those who can’t afford to renovate and tenants of every type of home.
If the building codes require new homes and major renovations to be net zero emissions, they will not only be delivering some of the most cost effective and achievable emissions reductions in Australia that we need to make, they will also be more naturally comfortable, healthy, and cheaper to operate.
Can we design and build net zero emissions homes? Yes we can – they are being created right now, all around Australia, by architects, engineers and builders employed by good clients and developers who realise this is the future for housing. Groups are being set up to help them share their insights into how to best achieve this with their colleagues, so the whole industry can collaborate to make this happen as fast as possible. A rising tide lifts all boats.
Will they cost more? Time and again, the increase of energy efficiency levels has been shown to be much less expensive than modelling might have shown. This is usually because worst case scenario, badly designed or inappropriate homes are often used as a baseline. Good design, with appropriate orientation and window/door sizing, will not cost a lot more and be much cheaper to run. As the industry changes, supported by the certainty of the regulations, the costs will drop. Additionally, making your home slightly smaller will not only reduce costs, but also emissions associated with its construction and operation.
Do I really have to give up my gas cooktop? Not only do induction cooktops work better and are easier to clean, they don’t put particulates into the air in your home which are not good for anyone. Especially those with asthma or other breathing difficulties.
As we become more familiar with embodied energy and how to accurately account for it, we will move towards “zero emissions life cycle homes”. Homes that account for all the emissions required to make, maintain, and operate them.
If not these emissions – which ones? How will we achieve our international promises and help the world remain liveable for future generations? Net zero emissions housing is ready to go, cost effective with great social side benefits for all Australians. With good design and the creative skills of architects, engineers and builders, we can produce delightful, healthy homes that don’t cost the earth :-)
What do we want? Zero emissions homes! When do we want them? Now!
Sign up to support this initiative at https://nzencc.nationbuilder.com/
Examples of zero emissions housing already underway in Australia:
https://csiropedia.csiro.au/doors-open-on-australias-first-zero-emission-home/
https://joshshouse.com.au/about-the-project/
https://new.gbca.org.au/news/gbca-media-releases/property-leaders-commit-net-zero-future/