The construction industry is seeing an increasing number of requests for low-carbon construction-related information, such as the climate impact of products, carbon footprints, carbon handprints, and EPD documents. New legislation requires comprehensive emissions assessment and reporting across the entire life cycle of buildings, which increases the need for reliable data throughout the value chain. Companies must therefore understand what data is needed in different situations and how to produce it correctly. This blog explains the key concepts, calculation principles, and practices that enable companies to effectively meet these growing requirements.
‘What does low-carbon construction mean?
According to the Building Act (751/2023), new buildings must be designed to be low-carbon. The carbon footprint and carbon handprint of both the construction site and the building must also be reported in the climate assessment prepared for the final inspection. At the end of 2024, the Ministry of the Environment issued a regulation concerning climate reports for buildings and building product catalogs. These have, for their part, contributed to the growing need for reliable data in the construction sector. The regulation specifies the data requirements for low-carbon construction, as well as various definitions for the necessary information.
Under the regulation, companies must conduct a climate assessment that includes evaluations of the carbon footprint and carbon handprint of the building as well as the construction site. The assessments must include data covering the entire life cycle of the building and the construction site. That is, from the procurement of raw and other materials to the emissions generated during and after the building’s use. In accordance with the regulation, calculating GHG emissions is enough and is not necessary to assess other environmental impacts.
A carbon footprint assessment must include the following steps:
- A1–3 Manufacture of construction products
- A4 Transportation
- A5 Site operations
- B4 Replacement of construction components
- B6 Energy use
- C1 Demolition
- C2 Transportation of demolition waste
- C3 Treatment of demolition waste
- C4 Final disposal of demolition waste
- Total carbon footprint
A carbon handprint with a positive impact on the climate consists of the following components:
- Reuse
- Recycling
- Excess renewable energy
- Products’ carbon storage effect
- Carbonation
How is the carbon footprint of a building calculated?
A large portion of the data used to calculate climate impacts and emissions comes from the building product catalog. It lists all the materials, raw materials, and components used in the building. In addition, the calculation includes work related to the construction site prior to the actual construction. The completed building is estimated to have a 50-year lifespan, so the calculation also includes parts and materials that may need to be replaced during repairs.
The quantities of the materials to be used are combined with accurate and up-to-date emission factors. The OpenCO2 emissions database currently contains approximately 8,000 emission factors. The emissions database contains a comprehensive selection of primary—i.e., supplier-specific—emission factors related to construction and building materials, as well as general average factors. Primary data directly from suppliers generally ensures lower and more accurate emissions figures.
What is a carbon footprint?
The carbon footprint describes the climate load caused by a specific configurable entity. The carbon footprint can be calculated, for example, for a company, municipality, investment, product, or service.
The climate load is caused by the release of greenhouse gases such as carbon dioxide (CO2), methane (CO4), and nitrous oxide (N2O) into the atmosphere. The carbon footprint is expressed in terms of carbon dioxide equivalents, considering the different global warming effects of different greenhouse gases.
When determining the carbon footprint, all direct and indirect emissions during a life cycle associated with a specific entity need to be taken into account. For example, in the case of a company or municipality, the carbon footprint can be determined per selected unit of time, such as a year.
The carbon footprint is expressed in terms of mass, either in tonnes, kilograms, or grams.
What is a carbon handprint?
The carbon handprint describes the positive climate impacts of a particular solution throughout its life cycle. A positive carbon handprint arises from the fact that using the solution provided reduces the carbon footprint of someone else (usually the customer). On the other hand, reducing the carbon footprint of one’s own operations does not increase the carbon handprint.
The carbon handprint of the same product or service may be different depending on the situation, for example, in different markets. Therefore the carbon handprint is always determined in relation to the selected baseline.
VTT and LUT University have developed a carbon handprint calculation methodology and published a guide. According to the guide, a positive carbon handprint can be achieved, for example, by improving material or energy efficiency, replacing non-renewable materials or energy with renewables, extending product lifetime, reducing waste and reducing losses, or capturing and storing carbon dioxide. The carbon handprint can be used, for example, to communicate the climate benefits of a product or service to customers or other stakeholders.
What is EPD?
An EPD (Environmental Product Declaration) is prepared as a life cycle assessment (LCA) covering the entire life cycle of a product. It describes the product’s environmental impacts and includes environmental impacts beyond greenhouse gas emissions, such as impacts on soil and bodies of water. The EPD document for construction products is typically prepared in accordance with the SFS-EN 15804 standard and must undergo third-party verification. After verification, the EPD is valid for five years.
Many companies in the construction industry produce EPDs for their own products. An EPD is a reliable and comprehensive report on the environmental impacts of a product or material, and is quite common today. For many companies, however, preparing, verifying, and publishing an EPD in the EPD system can be an expensive and labor-intensive first step. And if, for example, a customer does not specifically require an EPD, calculating the product’s carbon footprint may be a simpler and more cost-efficient option for assessing its climate impacts.
In case you have questions about the climate impacts of construction and the emissions data required, you can book a free consultation with one of our experts below, and together we’ll find the right solution for your company to meet the requirements of low-carbon construction!
OpenCO2net offers comprehensive emissions calculation tools and an extensive, up-to-date OpenCO2 emissions database tailored to your company’s needs. Our experts are here to assist you with your climate work, providing exactly the level of support you need. You can choose just the tools or emission factors, the “Calculate and Learn Yourself” package, or comprehensive consulting services!
