Wondering how to measure your home’s carbon footprint, and where the biggest reductions can be made in your sustainable home?

Discover why embodied carbon can outweigh operational carbon in a modern all-electric home, and what to do about it during design.

Learn the tools, material choices and conversations to have with your team so your project’s carbon impact is measured, not guessed.

Listen to the episode now.

Hello! This is Episode 418, and Way #18 of the ‘44 Ways to Create Your Sustainable Home’ series here on the podcast. This episode completes Section Four: Modelling and Measuring Your Sustainability.

Across this series, we’ve talked a lot about energy efficiency, and how reducing operational energy in turn reduces the carbon emissions associated with running your home. 

At the same time, we’ve got better at measuring the embodied carbon in construction, and it’s increasingly being seen as the required area of focus to reduce the impact this industry has on the climate.

Way #18 is: Measure Your Home’s Carbon Footprint.

In this episode, I take you through what operational and embodied carbon actually mean, why embodied carbon is becoming an increasingly significant part of the picture, and, if your carbon footprint is a sustainability consideration for your project, what you can do about it during design, and the conversations to have with your team.

It’s worth knowing that the term ‘carbon footprint’ was popularised by British Petroleum (or BP) in 2004, as part of a major advertising campaign that shifted the climate conversation toward individual responsibility, while the fossil fuel companies funding those campaigns merrily kept on with their own emissions. 

At the time, the global energy and fossil fuel sector was responsible for roughly 65 to 70% of total worldwide greenhouse gas emissions.

Despite its not-so-honourable origins, considering and minimising your carbon footprint when designing, renovating or building, can be another way to pursue sustainability in your project. 

When it comes to your home, there are two types of carbon to consider: operational carbon (from running your home) and embodied carbon (from the materials your home is made of, across their full life cycle).

According to the Green Building Council of Australia, the average Australian home emits around six tonnes of carbon per year through operational energy use, and this will continue to fall as the electricity grid gets cleaner. 

However, the Global Status Report for Buildings and Construction (2025 – 2026) shares that the building and construction sector accounts for around 37% of global CO2 emissions and nearly 50% of global material extraction. 

And with half of the buildings that will exist in 2050 still yet to be built or renovated, the choices we make today will shape emissions, energy use and quality of life for generations.

In a conversation I had with Jeremy Spencer of Positive Footprints on the podcast back in Episode 232 and Episode 233, he shared a useful rule of thumb for Australian homes: for each square metre of floor area in a new build, there’s roughly one tonne of embodied carbon before anyone has moved in and started using the home. 

So with the average Australian home measuring around 230 to 240m2, that’s 230 to 240 tonnes of carbon locked in during construction. Against six tonnes of operational carbon per year, you can see the disparity, and why embodied carbon has become the dominant part of the carbon story for high-performance homes.

Embodied carbon is calculated using a Life Cycle Assessment, or LCA. 

An LCA looks at the carbon emissions across the entire life of a building material: raw material extraction, production and manufacturing, transportation to site, construction, use-stage embodied and operational carbon while the building is lived in, and end-of-life impacts including demolition, transport and disposal.

Most significantly, embodied carbon sits in the size of your home.

If you build smaller, you’ll make a big dent in your home’s embodied carbon. 

Next, it sits in structural efficiency, particularly the slab and any steel.

So the conversations we had in Way #5, Episode 405 (design a smaller, smarter home) and Way #7, Episode 407 (create an efficient structural design, collaboratively) do a lot of the heavy lifting here.

Then review the carbon footprint of the materials you do choose.

Suppliers including Holcim and Boral now offer lower-carbon concrete options that replace significant cement content with supplementary materials like ground granulated blast furnace slag and fly ash. Green steel and lower-carbon aluminium options are increasingly available. 

Environmental Product Declarations (EPDs) let you compare products, and calculators like E-Tool, One Click LCA and EC3 let you measure the whole home.

Unlike energy efficiency, there is currently no regulatory requirement in Australia (or in most other countries) for residential builders or designers to account for embodied carbon. Most professionals will not proactively raise it. 

So if embodied carbon matters to you, you’ll be well-served by finding a design team and builder who are already engaged with it, or raising it explicitly and asking them to address it.

In this Episode, I cover:

• Where the term ‘carbon footprint’ actually came from, including its origins in a 2004 BP advertising campaign
• The difference between operational and embodied carbon, and why embodied carbon has become the dominant part of the picture for high-performance homes
• The Global Status Report for Buildings and Construction 2025 – 2026, and what it says about our sector’s responsibility for global emissions
• A simple rule of thumb for the amount of embodied carbon in the average home
• What a Life Cycle Assessment (LCA) actually measures, including the stages it assesses, from raw material extraction through to end-of-life disposal
• Where embodied carbon sits in your home, and how home size, structural efficiency and material selection are the biggest levers
• Environmental Product Declarations (EPDs) and how they let you compare the carbon content of similar products
• The digital calculation LCA tools available (E-Tool, One Click LCA, EC3) for whole-of-home carbon measurement
• Why the greenest building is often the one that already exists, and what that means for renovation vs new build decisions

Plus a whole lot more.

LISTEN TO THE EPISODE NOW.

RESOURCES:

Episode 232 with Jeremy Spencer, Positive Footprints >>> Building Carbon Zero Homes

Episode 233 with Jeremy Spencer, Positive Footprints >>> How to Choose a Sustainable Builder

Episode 263 with Melanie Lupis, Sustainability Certified >>> How to Design and Build an Energy Efficient, Zero Carbon Home

Episode 280 with Dylan Viviers from Holcim >>> What is Low Carbon Concrete

Episode 281 with Dylan Viviers from Holcim >>> How to Specify Low Carbon Concrete

Episode 407 of the 44 Ways to Create a Sustainable Home series >>> Create an Efficient Structural Design, Collaboratively

Carbon calculators:

• Life Cycle Assessment software >>> Cerclos
• Carbon assessment tool for construction projects >>> One Click LCA
• Embodied Carbon in Construction Calculator >>> EC3

Environmental Product Declarations >>> EPD Australasia

UNSW Newsroom article on why embodied carbon is the new frontier in reducing greenhouse gas emissions >>> Embodied carbon in buildings: a new frontier in greenhouse gas reduction

DCCEEW’s overview of home energy ratings, disclosure, and minimum energy standards >>> Residential buildings

Peer-reviewed study by Sejal Sanjay Shanbhag, Manish K. Dixit, and Petros Sideris in Developments in the Built Environment (Vol. 20, Dec 2024) >>> Examining the global warming potential of hempcrete in the United States: A cradle-to-gate life cycle assessment

Green Building Council of Australia’s media release on new Australian homes emitting more upfront carbon than they will over 60 years of operation >>> Australia risks locking in millions of tonnes of carbon as housing boom accelerates

UNEP and GlobalABC’s tenth annual report tracking the buildings and construction sector’s progress toward a 2050 net-zero pathway >>> Global Status Report for Buildings and Construction 2025-2026

Aspire Sustainability Consulting’s overview of upfront, use-stage, and end-of-life embodied carbon in buildings >>> Life Cycle Assessments (LCA)

A free guide to simplifying sustainability across research, planning, design, materials, and building, from Amelia Lee’s 30+ years in residential design and construction >>> 44 Ways to Create a Sustainable Home

Access the support and guidance you need to be confident and empowered when renovating and building your family home inside my signature online program >>> HOME Method