Special conditions: what counts and why

What the “special conditions” category covers, and when it should be used in a calculation.

Special conditions are used for documented circumstances that make a construction more climate intensive than the reference value normally used for the relevant building part. The feature is relevant when the project uses a calculation mode that supports Special Conditions.

What is included?

A special condition is linked to a building-part group and can include information such as area, documentation and the constructions or building products affected. Quantities must match the building model. If the same construction is measured differently in the two places, the calculated climate impact will be misleading.

Only constructions that match the group’s unit can be used. A group measured in m² therefore cannot be linked to a construction measured in another unit.

Effect on the result

LCAbyg compares the calculated climate impact with a reference value for the building-part group. If the difference justifies an increased climate impact under the special-conditions rules, it is shown as an addition in the results. Several additions can be added together.

Special Conditions are active only for the BR18 (2023) and BR18 (2025) calculation modes. The page is not relevant in other calculation modes. See How to handle special conditions for the procedure.