Ramboll sets bold ambition to halve CO2 emissions from new building projects

The buildings industry is critical to global climate ambitions. It accounts for nearly 40% of energy-related greenhouse gas emissions (GHG), in large part due to the carbon-intensity of materials such as steel and concrete. As the global building stock is set to double by 2060, the need to reduce emissions is urgent.

Today, Ramboll is taking the lead by announcing a bold ambition to halve emissions from all new building projects globally by 2030, in line with our new group strategy, The Partner for Sustainable Change. In doing so, we will reduce emissions by 2.5 million tonnes of CO2 annually compared to a 2021 baseline, in line with recommendations from the World Green Building Council to halve emissions in the buildings industry.

The focus of this reduction target is the embodied carbon of buildings, meaning the greenhouse gases released during the lifetime of building materials, from raw material extraction, transport, production, construction and building use, dismantling and disposal. Embodied carbon from building projects accounts for 11% of global CO2 emissions, and on average amounts to 600 kg of CO2 per square metre throughout the lifetime of a building, according to research from Ramboll and the Laudes Foundation from five European countries.

“Globally, embodied carbon accounts for 20–25% of a building’s emissions, but that number jumps to 90% in the most energy efficient buildings,” says Peter Heymann Andersen, Group Chief Operating Officer of Ramboll with responsibility for the company's global Building business.

"Today, the vast majority of new buildings in the EU are designed as almost-zero-energy buildings, and the little energy used to power the buildings will soon be CO2 neutral. In other words, the buildings of the future will emit only minimal amounts of CO2 once they are built. However, there are still huge emissions from the production of materials used in the construction phase,” he adds.

Kaj 16 in Gothenburg, Sweden is a textbook example of how designers and architects can reduce embodied carbon. To meet the sustainability requirements of the client, Ramboll first modelled 17 different versions of the building using different building materials and accounting for the carbon cost of each, in addition to other client criteria such as weight and ceiling height.

"Ramboll has proven that by simply managing a carbon budget, you can reduce embedded carbon emissions by 30% at no extra cost" — Peter Heymann Andersen, Ramboll Group Chief Operating Officer

The winning design was a hybrid of timber and concrete, which was even more sustainable than a pure timber build. Once finished, the 37,500-square-metre multi-use building will have a 30% lower carbon impact than a similar concrete building. The ambition is also that Kaj 16 will be LEED Platinum certified, the highest possible accreditation in the LEED standard.

Read more: How Ramboll optimised Kaj 16 for carbon footprint and circularity

From 2022, Ramboll has started calculating the embodied carbon on all new buildings projects globally that are larger than 1000 square metres.

Reducing emissions will require engineers and architects to use carbon budgets, and for the industry to provide accurate data on the carbon cost of different building materials, says Peter Heymann Andersen.

"The idea behind a carbon budget is to set a maximum limit for a project’s total carbon emissions over time, which engineers and architects then base their design and material choices on. If you end up over budget, you will have to go back and change some of your decisions. Ramboll has proven that by simply managing a carbon budget, you can reduce embedded carbon emissions by 30% at no extra cost," he explains.

In parallel, getting more accurate data on the carbon intensity of building materials will be key:

"In order for us in the building industry to be able to calculate the actual climate impact of buildings and choose ‘best in class’ products – products that have a lower CO2 footprint than their direct competitors – it is crucial that we have much more precise environmental product declarations available," he adds.

Today, there is a lack of product-specific data for many building materials, which means that designers and engineers are forced to rely on generic data, which is less accurate.

To tackle this problem head on, Ramboll is urging producers of building materials to document carbon impact through Environmental Product Declarations (EPDs). For the most sustainable manufacturers, Ramboll expects EDPs will become a competitive advantage.

• Due to global population growth, the global building stock is expected to double by 2060 – adding 230 billion square metres of new floorspace in total, according to the Global Alliance for Buildings and Construction. This is equivalent to building as many buildings as there currently exists in the UK – every year.
• Today, the global construction industry accounts for almost 40% of the world's energy-related CO2 emissions. 28% of the emissions come from building operations – for example, energy consumption for heating, cooling and light. The remaining 11% comes from the embodied carbon in building materials, according to UNEP and the Global Alliance for Buildings and Construction.
• Ramboll designs approximately 15% of all new buildings in Denmark.