How to use EPDs in your building project

Environmental product declarations (EPDs) are an important tool for consultants and developers who want to know the environmental impact of the different materials used in a building project.

The following describes how to use EPDs, and explains why we at Troldtekt aim for full transparency in our EPDs.

Environmental product declarations are a tool for professionals in the building industry who need to know the environmental impact of various building materials.

At Troldtekt, we have prepared and third party-verified product-specific EPDs in accordance with the EN15804+A1 standard. You can find the EPDs here:

In order to ensure that consultants and developers have the most transparent data possible, we have chosen to have separate EPDs for our different products rather than having only one EPD based on average values.

Informed choices based on EPDs

Basically, an EPD does not say whether a particular building material is more or less sustainable. The strength of an EPD lies in the fact that it makes it possible for consultants or developers to assess the environmental impact of different building materials – and to make informed decisions based on the various EPD data.

The manufacturer of the building material prepares the EPD. The declaration is based on a thorough life cycle analysis (LCA), which in Troldtekt’s case is prepared by Stefan E. Danielsson, MSc, who has been affiliated with the cement producer Aalborg Portland. The final EPD must be verified by an independent third party before it is published for professionals in the building industry. The German Institut Bauen und Umwelt e.V. (IBU) has verified and published Troldtekt’s EPDs. Through reciprocal recognition agreements, Troldtekt’s new EPDs will soon also be published by BRE, EPD International, EPD Denmark and EPD Norway.

An important tool for certified building

There is a growing demand for documented sustainable buildings, which is reflected, among other things, in the growing number of buildings that are achieving one of the acknowledged certifications. Here, EPDs play an important role. Both because the underlying life cycle analysis is used to assess the environmental impact of the entire building, and because EPDs document the environmental impact of the individual building materials.

Complete overview of environmental impacts

A product-specific EPD shows a particular building material’s total emissions and resource consumption during the stages of the material’s useful life covered by the EPD. It covers, for example:

  • CO2 emissions
  • Energy consumption
  • Water consumption
  • Waste generation

In addition, the EPD indicates how the building material contributes to ozone depletion, smog and acidification.

Not all EPDs are equally informative

Even though all EPDs are based on the analysis of the building material’s life cycle, not all EPDs contain information on the environmental impact throughout the entire useful life of the material. Until now, it has been a requirement that the EPD should contain data on the material’s environmental impact in the early stages of its useful life: raw material supply, material manufacture and transport to the building site. However, the subsequent stages – including the environmental impact of the building material during use as well as during de-construction demolition – are not documented in many EPDs.

From October 2022, new EPDs also have to provide information on the environmental impact of building materials after the end of their useful life. Troldtekt’s product-specific EPDs have all been prepared in accordance with the EN 15804 standard, and to ensure maximum transparency, the EPDs also contain various data on the use stage.

The five life cycle stages covered by an EPD can be seen in the table below. The stages A1-A3 and (from 2022) C1-C4 and D are mandatory, but as can be seen, Troldtekt includes several other stages. Usually, a building material will have a greater environmental impact the more stages are reported in the EPD. Therefore, it is very important to compare the same stages when comparing different building materials.

It is also relevant to consider whether any post-installation finishing is needed, which is not included in the life cycle analysis. Troldtekt acoustic panels are supplied painted or unpainted and do not require paint or filling after installation. Therefore, no further environmental impact occurs once the panels have been installed.

Troldtekt’s EPDs include stages A1-A3, A4-A5, B1, C1-C2, C4 and D (MND = Measurements not declared and MNR = Measurements not required).

When comparing several products, it is important to try to conduct the assessment based on the same stages.

How to read the EDP tables

The tables showing the results of the life cycle analysis are a key element of the EPDs. The tables show the imprints of the materials in the various life cycle stages, which are measured using different units, depending on whether you look at carbon footprint, acidification, energy consumption or something else.

  • Column 1 shows what the figures express. One example is GWP, which stands for Global Warming Potential. The abbreviations are explained under each table.
  • Column 2 shows the unit of measurement applied. For GWP, the unit is ‘kg CO2 eq.’, which stands for carbon dioxide equivalent per square metre of the building material. The figure includes all greenhouse gases, and their different climate footprints are converted into one comparable (equivalent) value.
  • The other columns show the life cycle stages of the building material that the value says something about.

The number values in the tables are written in scientific notation (based on powers of 10). E+ means that zeros must be added after the number, and E- means that zeros must be added before the number (decimal number). Finally, E+0 means that the number in front is the real value. Here demonstrated in three examples:

  • 6,77E-1 corresponds to 0,677 (GWP in A1-A3)
  • 4.50E+1 corresponds to the value 45 (ADPF in A1-A3)
  • 8.18E+0 corresponds to the value 8,18 (GWP in C4)

Wood and cement in EPD carbon accounts

EPDs are therefore an effective tool for getting an overview of a building material’s environmental impact during the various stages of its useful life. Troldtekt acoustic panels are made of wood, which is sourced from Danish forests, and cement, which is extracted from the Danish subsoil. While cement production emits significant amounts of CO2, wood pulls significantly in the opposite direction because of the CO2 that is stored in the wood when the tree is growing. At the same time, the cement content of the Troldtekt panels means that they absorb CO2 during use as a result of the chemical process of carbonatisation. This CO2 is stored in the acoustic panels until the building is demolished.

The combination of wood and cement gives Troldtekt a relatively low carbon footprint during the raw material supply stage, and as we use almost entirely carbon-neutral forms of energy when manufacturing our panels (wind power and heat from our own biofuel plant), the total carbon footprint in stages A1-A3 is low.

Incineration counts in the CO2 accounts

At the end of their useful life (50-70 years), Troldtekt acoustic panels usually end up at a recycling centre and are incinerated, which contributes energy in the form of heat. In connection with the combustion process, the stored CO2 is released from the wood. This means that most of the CO2 emissions from the acoustic panels stem from stage C4, which covers the end-of-life stage.

As part of Troldtekt’s Cradle to Cradle strategy, measures are in the pipeline that will reduce the carbon footprint associated with disposal, and thus result in lower CO2 emissions during C4. Among other things, we are launching a pilot project with a number of Danish municipalities which involves collecting cement-bonded wood wool waste from recycling centres, so that it can be incorporated as a raw material in the production of new cement at Aalborg Portland.

In the EPDs, the data is based on current disposal methods. In practice, this means that the C4 stage is calculated according to the way in which the 50 to 70-year-old cement-bonded wood wool panels are disposed of today (incineration), rather than the way in which Troldtekt expects its acoustic panels to be recycled in 50-70 years’ time.

The graphs show the carbon footprint of Troldtekt acoustic panels in the different life cycle stages.

During use (stage B1), carbon emissions are negative because Troldtekt acoustic panels absorb CO2 through the chemical process of carbonatisation.

The recycling potential (stage D) also results in negative CO2 emissions for Troldtekt.

However, the overall carbon footprint over the entire life cycle of the product is positive because we declare incineration as a disposal scenario (C4).

Take care when comparing

When, as a professional in the building industry, you compare EPDs that describe the environmental impact of a building material once it has reached the end of its life, you must make sure to base your comparisons on the right parameters. While some material manufacturers (including Troldtekt) state incineration as a method of disposal, others choose to state landfill – i.e. where the waste is buried.

In Denmark, we do not traditionally use landfill, which is considered the worst environmental solution as the waste is not used at all. However, in an EPD context, this may look like a sensible solution because the CO2 stored in wood products is not released when this method is used.

At Troldtekt, we recommend that old cement-bonded wood wool panels are burned rather than being sent for landfill, and to be as transparent as possible, the carbon footprint from incineration is therefore stated in our EPDs.

Go for product-specific EPDs

Above, we have described the so-called product-specific EPD –i.e. the declaration that describes how a specific building material impacts the environment.

However, if no EPD is available for the building material you want to use, you can either use a so-called industry average or sector EPD or rely on generic data from the ÖKOBAUDAT database.

Sector EPDs state an average for how building materials within a particular industry typically impact the environment. For example, you might have a sector EPD for concrete elements, windows, construction timber, tiles/brick etc. There is no sector EPD for cement-bonded wood wool products.

If possible, you should always choose product-specific EPDs, as these provide the most accurate data. For the same reason, you are required to add 10 per cent to the EPD values if you are using a sector EPD in connection with the certification of a building project. And if you use generic data, you need to add 30 per cent to the data.

>> Download Troldtekt’s EPDs