Why measuring buildings’ lifetime carbon emissions is key to a net-zero future


Australia is now falling behind Europe in measuring and regulating embedded carbon in building materials.

“Unless we start regulating the use of [materials in buildings] in terms of embodied carbon impact, we are missing the proverbial elephant in the room. So says Paul King, Managing Director of Sustainability and Social Impact for Lendlease in Europe.

Vicky Bullivant, Global Head of Sustainability at Laing O’Rourke, agrees: “Reducing GHG emissions from the built environment requires urgent action from many parties, including non-industrial actors. That’s why we welcome the Z part – [it] would increase industry-wide focus on ways to accelerate and achieve the required progress.

Life cycle carbon emissions are the key to a net zero building. These are the carbon emissions resulting from the materials, construction and use of a building over its lifetime, including its demolition and disposal.

A WLC assessment provides a true picture of a building’s carbon impact on the environment. These construction emissions contribute 11% of our total global emissions, according to the World Green Building Council.

A quarter of Australian construction companies signed up to the council’s call for net zero buildings by 2050 in 2019.

For example, a group of architects and the construction industry in the UK have proposed an amendment to the building regulations called Part Z intended to take into account the significant contribution that the embodied carbon of buildings makes to the emergency climatic.

It calls for legislation to mandate reporting of carbon emissions in the built environment, as well as limiting embodied carbon emissions from projects.

It is believed that it is not a question of if it will happen but when, especially as London is already backing Party Z when it comes to new builds.

The London Plan?Policy SI 2?sets out a requirement for development proposals to calculate and reduce WLC emissions, as part of a WLC assessment.

More skyscrapers?

Some have taken this as a prediction 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 assessing the sustainability of the built environment, both in terms of carbon and other measures of sustainability. ‘environmental impact.

The EN 15978 Durability of construction works standard contains the methodology for carrying out life cycle analyzes (LCA).

Of course, you should always select the correct emission factors for each material or product, especially for the product stage, which you can do by consulting the Environmental Product Declarations manual in EN 15804.

But for those who want to hold hands to do this complicated calculation, the professional statement from the Royal Institution of Chartered Surveyors (RICS PS) Carbon footprint over the entire life of the building environment is now here to help.

This is used by most, if not all, UK industry professionals who undertake Whole Life Carbon Assessments (WLCAs).

The Greater London Authority’s WLCA guidelines for the New London Plan are heavily dependent on this.

This is why the authors of Part Z recommend that the UK government standardize the use of PS.

The PS is currently being revised to establish additional baseline assumptions for the use and end-of-life stages of a building (e.g. replacement periods, maintenance and repair proportions, etc.) and end-of-life scenarios for construction elements.

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 Center for Window and Cladding Technology’s An introduction to sustainability in facades, and the Chartered Institution of Building Services Engineers’ TM65 for building services.

Australia is lagging behind

The momentum is accelerating for similar measures in Australia.

Embodied carbon will replace operational carbon as the main source of building emissions as Australia’s power grid decarbonizes, says the Green Building Council of Australia. It’s going to happen all over the world.

Without action, the share of Australia’s overall greenhouse gas emissions caused by carbon embodied in buildings could rise by more than 50% between 2019 and 2050, according to a joint report by thinkstep-anz and Green Building Council of Australia.

Last month in The fifth stateThe Australian Institute of Quantity Surveyors has called for Australian-based embodied carbon standards that are independent, transparent and in line with international standards ISO 14025 and EN 15879.

AQIS is working with MECLA, NABERS and the GBCA to develop a national framework to measure, certify and compare emissions from construction and building materials.

Elizabeth McIntyre, chief executive of Think Brick Australia, says it is essential to include these emissions in an environmental impact assessment.

“Standards commonly used in Australia take a ‘cradle-to-gate’ approach, measuring only the environmental impact of building materials during the extraction and manufacture of the product,” she says.

However, it is estimated that it will likely take five years before Australia has the same lifetime carbon requirements for new buildings already in use 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, says Stephen Hayes of First Sentier Investors.

It has just launched 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 stocks that meet the fund’s carbon standards.

Mr. Hayes said The Australian Financial Review, “A few do it on an asset or development basis, but that’s the first step. The next step is to produce this across their entire portfolio.


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