Australia is now falling behind Europe when it comes to measuring and regulating the embedded carbon in building materials.
“Unless we start to regulate the use of [materials in buildings] in terms of the embodied carbon impact we are missing the proverbial elephant in the room.” So says Paul King, Lendlease’s managing director of sustainability and social impact in Europe.
Laing O’Rourke’s global head of sustainability, Vicky Bullivant agrees: “reducing GHG emissions from the built environment requires urgent action from many parties, including non-industry players. That’s why we welcome Part Z – [it] would increase the entire sector’s focus on ways to accelerate and make the progress required.”
Whole life-cycle carbon emissions are the key to a net zero building. They are the carbon emissions resulting from the materials, construction and the use of a building over its entire life, including its demolition and disposal.
A WLC assessment provides a true picture of a building’s carbon impact on the environment. These emissions in construction contribute 11 per cent of our total global emissions, according to the World Green Building Council.
One quarter of Australian construction firms signed up in 2019 for the council’s call for net zero buildings by 2050.
So a group of architects and the construction industry in the UK has proposed an amendment to the Building Regulations called Part Z intended to account for the significant contribution that the embodied carbon of buildings makes to the climate emergency.
It seeks legislation towards mandatory reporting of carbon emissions in the built environment, along with limiting embodied carbon emissions on projects.
It is thought that it is not about if this will happen but when, especially since London is already supporting part Z as far as new construction goes.
London Plan?Policy SI 2?sets out a requirement for development proposals to calculate and reduce WLC emissions, as part of a WLC assessment.
No more skyscrapers?
Some have taken this as a forecast that the end of skyscrapers getting planning permission is in sight.
Will Arnold, head of climate action at the Institution of Structural Engineers, points out that European Standards already exist for the assessment of the sustainability of the built environment, both in terms of carbon and other environmental impact metrics.
EN 15978 Sustainability of Construction Works contains the methodology for conducting life cycle assessments (LCAs).
Of course you still need to select the right emission factors for each material or product, particularly for the product stage, which you can do by looking it up in the Environmental Product Declarations manual in EN 15804.
But for those who want their hand holding doing this complicated calculation, the Royal Institution of Chartered Surveyors’ Professional Statement (RICS PS) Whole life carbon assessment for the built environment is now there to help.
This is used by most, if not all, UK industry professionals undertaking whole life carbon assessments (WLCA).
The Greater London Authority’s WLCA guidance for the New London Plan heavily relies on it.
This is why the Part Z authors recommend that the UK Government standardise the use of the PS.
The PS is currently being revised to set out additional baseline assumptions for the in-use and end-of-life stages of a building’s life (eg replacement periods, maintenance and repair proportions, etc.) and end-of-life scenarios for typical building components.
This has already started to happen within industry bodies, such as the Institution of Structural Engineers’ How to calculate embodied carbon (2nd ed., 2022), the Centre for Window and Cladding Technology’s An introduction to sustainability in facades, and the Chartered Institution of Building Services Engineers’ TM65 for building services.
Momentum is growing for similar measures in Australia.
Embodied carbon will replace operational carbon as the dominant source of building emissions as Australia’s electricity grid decarbonises, says the Green Building Council of Australia. This is going to happen everywhere in the world.
Without action, the share of Australia’s overall greenhouse gas emissions caused by embodied carbon in buildings could rise by over 50 per cent between 2019 and 2050, says a joint report by thinkstep-anz and the Green Building Council of Australia.
Last month in The Fifth Estate, The Australian Institute of Quantity Surveyors called for Australian-based embodied carbon standards which are independent, transparent and meet international standards ISO 14025 and EN 15879.
AQIS is working with MECLA, NABERS and the GBCA to develop a national framework for measuring, certifying, and benchmarking emissions from construction and building materials.
Think Brick Australia’s chief executive Elizabeth McIntyre says it’s vital to include these emissions in an environmental impact analysis.
“The standards commonly in use in Australia take a ‘cradle to gate’ approach, only measuring the environmental impact of building materials during product extraction and manufacture,” she says.
However the estimates are that it is likely to be five years before Australia has the same whole life carbon requirements for new buildings that are already operating in the UK.
The Australian Institute of Architects is working on a proposed national standard, as is the Australian Institute of Quantity Surveyors.
This puts investors at risk, First Sentier Investors’ Stephen Hayes says.
He has just started a Global Property Securities Fund, which invests in listed securities, including UK developer British Land and student accommodation provider Unite. He says it was harder to find Australian property securities that meet the fund’s carbon standards.
Mr Hayes told The Australian Financial Review, “A couple do it on an asset or a development basis, but that’s the first step. The next step is producing this on their entire portfolio.”