Overview
The Graue Energie tool is One Click LCA's dedicated calculation tool for projects pursuing certification under the Swiss Minergie scheme. It enables architects, engineers, and sustainability consultants to perform whole life carbon assessments that meet Minergie's embodied energy and embodied greenhouse gas (GHG) emissions requirements, using the official Swiss KBOB dataset.
What is Graue Energie?
Graue Energie — German for "grey energy" — refers to the embodied energy and embodied carbon associated with the production, transport, replacement, and end-of-life treatment of construction materials and building components. Under the Minergie standard, projects must demonstrate that their grey energy and embodied GHG emissions remain within defined limit values for the building typology, alongside operational energy performance.
When to use the Graue Energie tool
Use this tool when your project is:
Pursuing Minergie, Minergie-P, Minergie-A, or Minergie-ECO certification in Switzerland
Required to demonstrate compliance with grey energy and embodied GHG emission limit values
Required to submit results in the Minergie-accepted format using KBOB data
Accredited tool status
One Click LCA is officially accredited under the Minergie tool accreditation program, and is the first non-Swiss provider to receive this accreditation. This means projects using the Graue Energie tool can be submitted for Minergie certification with confidence that the calculation methodology and outputs meet the scheme's requirements.
Scope
Applicable Projects
The Minergie LCA methodology can typically be applied to:
New construction projects
Major renovations and refurbishments
Residential buildings
Office buildings
Educational buildings
Mixed-use developments
The assessment scope should include all major building elements and technical systems contributing significantly to environmental impacts.
Life-Cycle Stages
The following life-cycle stages are generally considered within the Minergie assessment framework:
Life-cycle stage | Description |
A1–A3 | Product stage (raw materials, transport, manufacturing) |
B4 | Use phase: Replacement of building components |
C3–C4 | End-of-life stages: Waste processing for reuse, recovery and/or recycling and Disposal of waste |
Note for B4 stage: Replacements are calculated in a fractional replacement method. It means that if a material has useful service life at the end of the building life cycle, the remaining service life is allocated off of the building scope. For example, if the service life of a material is 40 years, the replacements are 1 - 60/40 = 0.5 replacements. Therefore, B4 would be A1-A3 + C3-C4 of the material multiplied with 0.5
Data Scope
The tool only uses KBOB environmental data (provided by ecobau and the Swiss Coordination Conference of Public Sector Construction and Property Services) as its underlying environmental dataset. KBOB is the official reference database for life cycle assessment in Switzerland, ensuring that all results align with the data sources accepted by Minergie auditors.
The assessment should prioritize high-quality environmental data sources:
Product-specific Environmental Product Declarations (EPDs)
Average EPDs
National or regional generic datasets
International generic datasets when local data is unavailable
One Click LCA supports EPDs compliant with:
EN 15804+A1
EN 15804+A2
Building Elements Included
Typical Minergie LCA studies include:
Foundations and substructure
Structural frame
Facades and envelope
Roof systems
Internal partitions and finishes
HVAC systems
Electrical systems
Plumbing systems
External works (depending on project requirements)
Operational energy use may also be included depending on the certification pathway and project stage.
Guidance
Creating a Minergie Project in One Click LCA
When starting a Minergie assessment in One Click LCA:
Create a new building LCA project
Select the appropriate country and assessment framework
Define the building typology and reference area
Calculation period is set to 60 years and cannot therefore be changed
Recommended LCA Parameters
The following settings are generally recommended:
Parameter | Recommended setting |
Service life | Product-specific service life |
All other inputs are not used in the tool.
Building materials selection
All material data should be added to the Building Materials query page.
To improve assessment quality:
Prioritize Swiss-specific EPDs whenever possible
Use product-specific manufacturer EPDs
Avoid mixing inconsistent datasets
Verify declared units and scope compatibility
Ensure all major materials are covered
It is advised to group the materials into constructions as they are presented in the elements. See more details about grouping materials as constructions in the following article: Group Materials As Constructions.
The downloadable report output will include breakdown of the components of each element with the relevant information on each of them.
One Click LCA automatically helps identify compliant datasets and compatible environmental data sources.
Reference values
Fill in reference data of your building for the purpose of threshold calculations of your building LCA values. Choose the correct building type(s) and their areas for new construction and enter the unheated area and renewable energy sources separately. For refurbishment projects, please input areas of each element (with the correct building type) that is included in the project scope.
Building area
Fill in the energy reference area, gross floor area and the unheated area in this query.
Carbon Hotspot Analysis
One Click LCA enables users to identify:
High-impact materials
Major life-cycle contributors
Replacement-heavy components
Structural carbon hotspots
Typical hotspots often include:
Concrete
Steel
Aluminum
Technical systems
High-replacement interior finishes
This analysis helps teams optimize material selection early in the design process.
Reporting and Documentation
The tool generates results using a fixed reporting template that aligns with Minergie's documentation requirements. These results can be downloaded in XLSX format from the More actions menu on the results page. Add this export as an attachment to your certification documentation.
Additional Resources
Useful resources for Minergie and whole-life carbon assessments include:
One Click LCA Academy (One Click LCA Academy)
Swiss construction and environmental regulations
For information on Minergie certification requirements, visit the official Minergie website.
For additional support, users can also contact One Click LCA experts and local support teams. (oneclicklca.com).