The responsibility of the architect and home occupier in reducing residential greenhouse gas emissions
Climate change is driving serious changes in the world that we must factor into building decisions. As a firm, we place importance on designing for the current climate as well as likely future climatic changes while seeing that designing and building with longevity in mind, as a key element in sustainable construction practices.
The construction, operation and maintenance of buildings accounts for almost a quarter of greenhouse gas emissions in Australia. Where and how we live have massive impacts on the level of emissions we produce as individuals, with the type of homes we live in playing a significant role. Australian residential greenhouse gas emissions are primarily created through transport (18.8%) and the use of electricity (33.1%).
The cover over the deck at the Allan St House was designed to restrict hot summer sun while allowing winter sun to penetrate into the internal living spaces. This in turn reduces the demand for heating and cooling.
Life Cycle
As Architects, we have a responsibility to design comfortable and efficient homes and as home occupiers we all share the responsibility of mitigating our usage of non-renewable resources. Life cycle emissions from all on-site activities need to be factored into the design of a home from construction to habitation. Traditional modes of building tend to rely on energy intensive practices though there are a range of measures that architects can take or influence during design and construction that can lead to a reduction in emissions. Architects can also be involved in the development of new modes of design and construction that are less energy intensive.
The use of prefrabicated mass timber panels at our High St Project reduces C02 emissions by 95 tonnes when compared to a conventionally constructed building. This reduction in emissions is equivalent to a Toyota Prado driving 29 times around Australia.
Some key areas to assist the management of energy demands post construction include knowledge about avoiding peak loads, providing energy storage and implementing smart user friendly management systems and interfaces. A simple example would be ensuring that selected heating and cooling systems can be divided into different zones and ensuring that the architecture allows for these zones to be sectioned off adequately.
Materials
Every building material comes with an environmental cost of some sort. So the first step in any strategy to use sustainable materials is to reduce the demand for new materials. Around 18.2 million tonnes (42%) of the solid waste generated in Australia is building waste. By choosing durable, low maintenance materials, the need for new materials and finishes over the building’s lifetime can be minimised. It’s also important to note that designs that are efficient in planning and structure, require less materials in the first place.
National policies aiming for ‘net-zero emissions and beyond,’ focus on operating emissions though embodied emissions in materials are also a key factor. As architects, this is another area that we can assist our clients to make decisions that lead to a reduction in emissions.
Brick was used at our Elm St House project for its durability as well as it capacity to work thermally as a heat sink as well as a cool sink, assisting the moderation of the indoor environment.
Integrated approaches to clean energy.
With a new home, there can be a clearer destination, as very little energy is needed to make a well-designed house comfortable. Appropriate insulation combined with passive solar design and a draught-proofed building, can create low or even no energy requirements for heating and cooling. Highly efficient homes with no heating or cooling input are possible across a majority of Australia.
The clients of our Elm St house have reported that their house stays comfortable all year round without the need of heating and cooling. Read more about this project here.
For existing homes, it’s important to identify that electric appliances are the largest contributor to Australian residential greenhouse gas emissions with the largest contributors being the fridge (33%) and TV/entertainment units (20%). Lighting, space conditioning and water heating collectively make up 1/3 of the overall emissions produced.
More than 2.5 million households now enjoy the benefits of rooftop solar across Australia with small-scale solar responsible for 22.3% of Australia's clean energy generation and 5.3% of the country's total electricity.
The typical use of solar is still quite limited without a battery as the highest solar generation during the peak sun hours between 11am and 4pm is when most occupiers aren’t home. High demands on power at night and low generation when experiencing poor weather means its business as usual with mains power being drawn upon. While battery roll out has been slow, systems are becoming progressively more affordable as competition in the market grows.
Rooftop solar is often seen as the silver bullet though it’s possible to drastically cut emissions by choosing the better appliances on the market. Typically, the best on market appliances use 50-80% less energy than the worst available and an extra star can mean a 15-30% energy saving.
Homeowners can also choose to buy certified Green Power but this doesn’t alter the importance of applying energy saving tactics in the home and considering the type of appliances, space conditioning and water heating systems in use.
At the end of the day, avoiding the creation of greenhouse gas emissions entirely is close to impossible. While we all should endeavour to reduce C02 emissions, carbon offsetting ultimately has to be a part of reaching carbon neutrality.
The array of solar panels on top of our Ruckers Hill House project. One element of a range of passive and active design decisions made to increase efficiency.
As Australian’s, we’ve lived in leaky buildings for so long, we’ve grown comfortable in our inefficient internal environments. Our relatively moderate climate has also contributed to us not confronting issues that a lot of other countries have. We’re a wealthy country; we emit a lot and export a lot of emissions and the harsh reality is that we’re nowhere close to doing what is needed to reach 2030 carbon emission reduction objectives.
As a firm, we believe that an awareness of the impact the building industry has on the environment is essential. We take pride in being a part of the pursuit in reducing carbon emissions produced during construction and later during habitation and apply developed practices to allow for home occupiers to be well set up to do the same.
