Over their lifetime, buildings are responsible for about 40% of global greenhouse gas emissions and use nearly half of all materials consumed in the EU. Because of this large impact, both government regulations and private sector initiatives aimed at achieving carbon neutrality are creating growing demand for low-carbon buildings.
The life cycle carbon footprint of buildings is the total impact that comes from all stages of its life. This includes material extraction and manufacturing, transportation, construction, maintenance, repairs, replacement of materials, use of energy and water during operation, and finally demolition and processing of materials at the end of its life.
At present, the largest share of a building’s carbon footprint comes from the energy it uses during operation. But research shows that the emissions built into construction materials also play a big role. As energy emissions go down due to cleaner energy supply and better efficiency, the share of embodied carbon becomes more important. For example, in Norway and Sweden, the majority of life cycle emissions for new buildings now come from sources other than operational energy use.
Regulations for the Life Cycle Carbon Footprint of Buildings
So far, most rules and policies designed to reduce the climate impact of buildings in Finland and abroad have focused on energy use during operation. These included requirements for energy efficiency and certificates. But in some markets, this has had only limited results. For instance, when Finland updated its building energy laws in 2018, most cost-effective improvements had already been applied, and further cuts in energy use could only be modest. This shows that new approaches are needed.
The next step is to regulate the entire life cycle of buildings, including the embodied emissions from materials, construction, maintenance, and end-of-life processing. Rules based on emissions also leave room for innovation, pushing the industry to develop better solutions. The Finnish Ministry of Environment has announced that its goal is to have life cycle carbon footprint regulation for buildings in place by the mid-2020s. These new rules will be introduced gradually, starting with the public sector. Similar efforts are also underway in other European countries. For example, the Netherlands already has regulations for building life cycle carbon footprint, and countries like Sweden and France are planning to follow.
What forms the basis for calculations?
The method for assessing the life cycle carbon footprint of buildings is set by the European CEN / TC 350 standards on sustainable construction. These include rules for building-level assessment (EN 15978) and environmental product declarations (EPDs) for building products, which are used in building-level assessments. These standards give a common framework across Europe and are considered leading methods globally.
In Finland, the Ministry of Environment is finalizing its national calculation method, which is based on these EN standards but gives extra detail. A public review of the method was completed in January 2019, and updates are still being made based on feedback. The method is being tested with real building projects.
This Finnish method considers emissions from material production, construction, replacements, energy use, and end-of-life. The assessment is done over the building’s service life, or if not defined, a default of 50 years. Emission factors for energy use are pre-set and take into account the expected decrease in emissions as the energy supply becomes cleaner.
In addition to the carbon footprint, the method allows buildings to show their positive impacts as a “carbon handprint.” This includes benefits like recycling materials after use, carbon stored in bio-based materials, reduced emissions from concrete carbonation, or selling extra renewable energy produced by the building. Manufacturers can also provide environmental product declarations (EPDs) to show the impact of their materials. These EPDs, published under EN 15804, give a standard and widely accepted way to communicate environmental effects. In Finland, EPDs are published by RTS.
How can carbon footprint be measured and reduced in real projects?
The life cycle carbon footprint of a building is largely decided during its design. Once construction is complete, opportunities to lower emissions are limited. This makes it important to take action early in the design process to guide the project toward the lowest possible carbon footprint.
Decisions at the concept stage—such as site selection, available energy sources, soil conditions, building shape, structural materials, and energy targets—set the foundation. Later, in detailed design, emissions can be reduced through energy efficiency, use of renewable energy, recycled and renewable materials, long-lasting materials, and minimizing material use. Even choosing between similar products matters, as emissions can vary greatly depending on the manufacturer.
For calculating the footprint, information needed includes:
- Building materials and their quantities (from drawings or building information models)
- Environmental impact and service life of those materials
- Energy use and energy sources (from energy calculations)
- Optional data on transport, construction works, and material end-of-life, or default values from national methods
The most reliable way to do these assessments is by using dedicated software with emission databases and built-in calculation methods. Such tools make it possible to start assessments early in design using average data, and later speed up detailed design by connecting directly with design software like building information models. These tools also ensure that the correct methods are applied, freeing the assessor to focus on collecting data and giving advice.
What services and tools are available on the market?
At present, one major tool available is the One Click LCA platform, developed by One Click LCA Ltd. This online tool includes features for carbon footprint, life cycle assessment, circular economy, cost analysis, and environmental product declarations. Its database includes over 10,000 building materials.
One Click LCA is used in more than 55 countries by companies such as WSP, ARUP, Bouygues, Statsbygg, and BRE. In Finland, it is used by Ramboll, Granlund, Optiplan, Sitowise, SRV, Stora Enso, the City of Helsinki, and others.
The tool supports Finland’s national calculation method and also works with certification systems like LEED, BREEAM, and RTS. It allows carbon calculations in the early design stages based on building type and size. The platform is also being expanded in partnership with the Finnish Wood Industry Association and the insulation industry to cover typical wood constructions and material options.
Finally, the tool is compatible with commonly used design software like Tekla, Revit, Archicad, IDA-ICE, Simplebim, and Solibri. This makes it easier for design teams to work efficiently and focus on lowering the carbon footprint of their projects.
