Short Answer
vyzn is designed for renovation and existing-building projects – on three levels you can combine cleanly: variant, component and material layer.
How It Works in vyzn
- Variant: You mark a model as «Umbau» (conversion) instead of «Neubau» (new build) in the action menu. This status controls, among other things, which components and building services count towards the Minergie-ECO and SNBS thresholds for embodied energy and greenhouse gas emissions – for a conversion, components and building services are weighted differently than for a new build (for a new build, only PV, geothermal probes and solar thermal collectors count on the services side; for a conversion, all services).
- Component: With the «Bestand» (existing) attribute you tag an element that already exists and should not be considered further in the calculations. In addition, the component's conversion status (new build vs. existing/conversion) feeds into the room zones of the SIA 380/1 energy balance – where each zone distinguishes between new build and conversion.
- Material layer: In the component build-up you can mark individual layers as «Vorhanden» (existing). These layers count as zero in the LCA (KBOB 2022: no embodied energy, no GHG emissions, no UBP, no biogenic carbon) – so only what you actually add or replace counts.
Practical Example
You model a replacement by marking the retained stock as existing and adding the new material as a regular layer that fully enters the balance – for example in a facade renovation: existing load-bearing structure «Vorhanden», new insulation and cladding regular.
Frequently Asked Questions
Is demolition included in the balance?
No – there is currently no dedicated demolition workflow that actively accounts for the emissions of removing existing building fabric (in the SNBS thresholds the demolition share is currently set to zero). vyzn covers the retained stock (excluded) and the new/replacement share (fully accounted).
What is the best way to start?
Describe your renovation scenario to us – together we will set up the structure so that existing stock, replacement and new construction are cleanly represented in your model.