How do I calculate the life cycle assessment (LCA) in vyzn?

Q: How do I calculate the life cycle assessment (LCA) in vyzn?

You calculate the life cycle assessment per variant directly from your model on the "Life Cycle Assessment" page. Prerequisites are a zone with an EBF classification and building components with a complete layer matrix; then you start the calculation via "Start calculation". The calculation is based on the KBOB 2022 LCA data, supplemented by SIA 2032 values.

Short Answer

The life cycle assessment (LCA) is one of the core building blocks of vyzn. You calculate it directly from your model – per variant, on the "Life Cycle Assessment" page. Once the prerequisites are met, a single click on "Start calculation" is all it takes; the calculation is based on the KBOB 2022 LCA data, supplemented by SIA 2032 preliminary study and preliminary project values.

Prerequisites

Define a zone with an EBF classification in the zone management so that the energy reference area (EBF) is available.
Assign building components with a complete layer matrix to your model elements in the catalogue: material per layer, layer thickness and service life.

vyzn checks these prerequisites automatically before calculating and points out any gaps specifically – for example a missing energy reference area, a component with a layer without an assigned material, or a component assigned in the variant that is missing from the catalogue.

Step-by-Step Instructions

Open the "Life Cycle Assessment" page of your variant.
Click "Start calculation".
Follow the progress: the process runs in several steps with a progress indicator – synchronising the catalogue, recalculating KPIs, LCA summary, detailed analysis, limit values and generating reports.

Expected Result

The calculation is based on the KBOB 2022 LCA data across the life cycle phases production, replacement and disposal, supplemented by SIA 2032 preliminary study and preliminary project values. Four indicators are reported – each per m² of energy reference area and year:

Greenhouse gas emissions (kg CO₂-eq/m²·a)
Embodied energy (kWh oil-eq/m²·a)
UBP
Biogenic carbon

The results are broken down by model elements, materials, building technology and other resources, including a classification against the Minergie-ECO limit values. For documentation, you can download the results as a report: as a PDF (according to SIA, Switzerland), as a CSV according to the GHG Protocol (60 years) and as a CSV according to Minergie Net Zero.

Common Mistakes

Missing energy reference area: no zone with an EBF classification has been defined.
A component contains a layer without an assigned material.
A component assigned in the variant is missing from the catalogue.
Outdated assessment: if you later change the model or the assignments, vyzn marks the assessment as outdated – update it via "Recalculate".

Update (version 1.8.5)

As of version 1.8.5, the prerequisite check gives more precise hints, and component issues are only shown when the component is actually assigned in the life cycle assessment. In addition, layer values (THGE/PEne) for merged material layers are now calculated correctly per layer, and the actual minimum values are shown on the LCA detail page.