To achieve net zero by 2050, every part of Australia’s economy has a role to play. In the building industry, there’s a focus on lowering the embodied carbon in building materials and embedding greater energy efficiency into new builds, but what can be done about our existing building stock?
What is the electrification opportunity?
Selwyn Saman, WSP’s Existing Building Decarbonisation Lead, says that there are many technical solutions that can transform existing buildings for net zero. He agrees that the rate of decarbonisation of the Australian electricity grid, driven by the rapid roll out of renewables, presents a huge opportunity.
“The latest federal government projections suggest the emission intensity from the Australian electricity generation will fall 90% by 2035 compared to 2023 levels,” Selwyn says.
Green electricity is an effective low-emissions option for powering a building’s heating, hot water, cooking and cooling requirements.
Selwyn says that gas used for heating and hot water represents about 15–25% of non-residential building energy consumption. Replacing this gas with green electricity presents the greatest opportunity for decarbonisation of existing buildings.
In some parts of Australia, such as Victoria, gas heating may still have a slightly lower emissions profile than the current electricity grid, but the grid is changing fast. An electric heat pump installed today can still provide emission savings of almost 50% over 15 to 20 years based on these projections.
Fig 1: Australian Electricity Emission Factor Projections
Of course, a 100%-electrified building that procures 100%-renewable electricity would radically reduce its operational emissions immediately. An example is Australia’s first all-electric major hospital, Adelaide’s New Women’s and Children’s Hospital, which WSP is supporting.
This new world-class healthcare facility will eliminate the use of any fossil fuels on-site, aligning with the Government of South Australia’s commitment to a 100% renewable energy by 2030. This will be achieved by connecting to the electrical network or through on-site renewable energy generation and storage.
Bernadette Fitzgerald, Director of Sustainability and Climate Change for WSP says, “A high-performing asset with patient and staff wellbeing at its heart were key for SA Health when defining the design of the New Women’s and Children’s Hospital. While we’ve been guiding the project team on a range of sustainable design features, the decision to go all-electric has been the most significant and only made possible by the robust feasibility assessment that each of our engineering disciplines contributed to.”
Is there a role for gas or green hydrogen?
Historically, using natural gas for heating and hot water in buildings provided lower operating costs and lower greenhouse gas emissions, so the rapid decarbonisation of the electricity grid has caught some parts of the industry off-guard.
Retaining gas heating appliances in anticipation of future decarbonisation of the gas network via green hydrogen is unlikely to be realistic. Even if the significant technical and safety challenges associated with green hydrogen are resolved, existing electric heat pump technology can already deliver significant benefits for efficiency and operating costs.
While green hydrogen may not be the solution for decarbonising buildings, it is still likely to be an enabler for decarbonising parts of our economy that are otherwise hard to abate. Green hydrogen and green ammonia could create an opportunity for Australia to maintain its status as a major energy exporter within a new global renewable energy trade.
Electrification doesn’t have to be all or nothing
Going all-electric is ideal from a decarbonisation perspective, but any reduction in gas consumption will help lower a building’s emissions.
Some buildings have relatively new gas boilers that still have many years of life ahead. Owners could naturally be reluctant to replace them. In this scenario, or where a building’s existing constraints make complete electrification extremely costly, a hybrid approach could be adopted in which gas heating is combined with electric heat pumps.
Starting with a hybrid approach as a step towards longer term complete electrification could help achieve some immediate emission reductions while staging the cost impact for clients.
Selwyn says, “Electrification represents the most significant opportunity for existing buildings to decarbonise, and while completely removing gas from buildings won’t always be easy, the first step is to understand the challenges and develop a strategy that best suits each building.”
Just as each individual building needs a decarbonisation strategy, we should also think about electrification strategies for entire property portfolios.
WSP, in partnership with Schneider Electric and Brookfield Asset Management, recently released a white paper, “A structured methodology for planning commercial real estate portfolio decarbonisation”, which explores opportunities to analyse and prioritise modernisation across complete asset portfolios to maximise return on investment and appeal to occupants while minimising disruption.
Understanding the impact of electrification
Electrification is a significant capital investment – and every building is different.
“We have recently completed studies for existing buildings in Canberra and Sydney,” says Selwyn, “and the difference in climate and energy tariffs drove very different system design and different impacts on operational costs and emissions.”
At this stage, there really isn’t a ‘one size fits all’ solution.
With this variability in mind, WSP developed an Electrification Impact Tool which allows quick assessment of the impact of a range of potential electrification design strategies (illustrated below).
Figure 2: Electrification Impact Tool inputs and outputs
It’s important that the tool isn’t overly simple, as overlooking key details could lead to a significant underestimation of operating costs and a misleading view of the level of emission reduction.
Multidisciplinary approaches informed by global experience
Given the number of existing buildings and the urgent need to decarbonise, we are seeing a sharp rise in activity in this space. To support our clients in reaching their decarbonisation goals, we have established an Existing Building Decarbonisation working group bringing together sustainability consultants and engineers throughout Australia. We’re also collaborating with our global teams to share expertise and lessons learnt from electrification projects worldwide, from initial feasibility studies through to post-completion tuning and verification.
Helping our clients to decarbonise existing buildings aligns with WSP Australia’s overall commitment to reduce the emissions footprint of our projects by 50% by 2030, and we have the multidisciplinary expertise to tackle the challenge holistically.
Contact our Future Ready team to help you apply this thinking on your next project, so that Australia’s built environment can play a greater role in protecting our natural environment.
Keen to explore more? Take a read of our global insight on, “What makes a building net-zero? - and other essential questions about decarbonisation.
