Building Circularity V2

A new and improved version of the Building Circularity tool allows calculation of building circularity through assessing the source and content of materials used, construction wastage, and material end of life (EOL). The tool expands on the previous version by allowing the user the option to use existing EOL scenarios or have more granular control of the processing type and share of material going to wastage and EOL.

This tool calculates material circularity at the beginning of the lifecycle according to ISO 59020 (2024), and can be used for HQE Economie Circulaire, London Plan Circularity Statement, Ellen McArthur Foundation Circularity Indicators as well as other circular design purposes.

The goal of the Building Circularity tool is to calculate the circularity percentage of your building/asset. It does not have a mandatory scope and can be used to access single materials or whole buildings.

As the tool is designed to work with many other tools, there are no data constraints. Therefore, it is recommended that the tool is added to an existing project with a completed Building materials query, then adding the additional data for calculating circularity, rather than adding materials directly.

The Building materials query will in many cases apply default values for many of the inputs required. For users of the previous version of the tool or our lifecycle assessment tools, many of the inputs will be familiar. Additional guidance has been provided to support adding the required inputs in the Building materials query for the material content and end of life.

Circularity Score Weighting Factors

In this query, you can adjust the weighting factors for the materials you have recovered and returned. Default values are provided but the factors are editable. If you make any changes on this query, remember to click Save at the top of the page. The query is divided into two sections: Materials Recovered (sourcing of materials) and Materials Returned (recovery of used materials).

Materials Recovered

• Virgin: New material which is not circular and has a default weighting factor of 0.
• Renewable: New material but from renewable sources, which is circular and has a default weighting factor of 1.
• Recycled: Recycled material which has lower emissions than an equivalent new material, which is circular and has a default weighting factor of 1.
• Reused: Materials reused from another project, which likely have no additional emissions. The default weighting factor is 1.

Materials Returned

• Reuse as material: Preparing materials for later reuse reduces further emissions and therefore has a default weighting factor of 1.
• Recycling: Recycling materials in a closed loop (maintaining the original material quality) has some emissions but lower than sourcing new materials. The default weighting factor is 1.
• Downcycling: Downcycling materials in an open loop (producing a lower quality material) has some emissions but lower than sourcing new materials. Due to the lower quality output the default weighting factor is to 0.5.
• Use as energy: Materials that can be incinerated incur emissions from the incineration process but can be used as energy (e.g. for heating, electricity, or production). Due to the incurred emissions from incineration (and the possible release of carbon in organic products), the default weighting factor is 0.5.
• Disposal: Materials landfilled may never fully disintegrate or decompose, so the default weighting factor for landfilling materials is 0.

Calculation Period

In this section, you will add a calculation period for your building so the calculations can be reflected based on the service life of the building. Type the service life of your building in the text box and then click save in the top right corner.

In this query you will add a calculation period (in years) for the building. This period reflects the service life of the building and therefore how frequently materials are replaced, which affects the calculation of end of life circularity.

Interpreting the Results

The chart at the top of the results page provides the overall Building Circularity Score and the individual scores next to it. The percentages on the left side of the chart use the weighting factors above to provide the overall percentages of Material Recovered and Material Returned. The Circularity Score is the sum of these divided by two.

A more detailed breakdown of both Material Recovered and Material Returned are provided below the chart, showing in kilograms the distribution of material recovery and returns per lifecycle stage. Clicking Details will also provide a further breakdown by each individual material used in the project.

The Key Material Groups table groups the results by material types and provides a breakdown and the Circularity Score for each.

EU Taxonomy

The EU Taxonomy table presents results to check compliance according to Construction of new buildings substantial contribution to circular economy. The first criteria requires at least 90% of non-hazardous construction and demolition waste (lifecycle stage A5) is reused or recycled. This is reported according to Level(s) 2.2 with a breakdown of each waste treatment type, indicated by the green box below.

The second criteria is that the use of primary raw material in the construction of the building is minimised through the use of secondary raw materials. The three heaviest material types used during construction, measured in kilograms, should be measured against the following criteria. The first two columns, Mass kg and Primary materials %, can be used to check compliance with this.

• for the combined total of concrete, natural or agglomerated stone, a maximum of 70% of the material come from primary raw material;
• for the combined total of brick, tile, ceramic, a maximum of 70% of the material come from primary raw material;
• for bio-based materials, a maximum of 80% of the total material come from primary raw material;
• for the combined total of glass, mineral insulation, a maximum of 70% of the total material come from primary raw material;
• for non-biobased plastic, a maximum of 50% of the total material come from primary raw material;
• for metals, a maximum of 30% of the total material come from primary raw material;
• for gypsum, a maximum of 65% of the material come from primary raw material.

Material Passport and DGNB Building Resource Passport (Gebäuderessourcenpass)

This version of the tool provides users with new options to download the results in Word format. For all international users, a Material Passport can be downloaded by clicking More actions on the Results page. For DGNB users there is also an option to export a Word report according to Version 1.1 of DGNB Gebäuderessourcenpass requirements.

It is recommended that a full life cycle assessment using the LCA for DGNB (DE 2023) tool is completed before adding the Building Circularity V2 tool to the project, to ensure only data suitable for DGNB is added to your bill of materials. Once complete, the extra details can be added in the Building materials query to calculate the circularity metrics, and the Word report downloaded directly from the Building Circularity V2 results page.

Please note that the Word report is linked to company account licences due to company information (name, logo) being added to the report.