Komponentlivslängd

How long a building part lasts before it needs replacing

Komponentlivslängd (component lifespan) is the expected number of years a specific building part lasts before it needs to be replaced or renovated. The roof, the facade, the windows and the installations all have different lifespans, and these figures are used to plan maintenance and work out what is coming over the next few years. Part of the cost of owning a house is not in the price you pay, but in what has to be replaced later.

Rules of thumb for roof, facade and windows

The figures below are common rules of thumb from the trade, not exact promises. Quality, location and how well the house has been looked after make a big difference.

Building part	Expected lifespan
Roofing felt (low-pitch roof)	approx. 20 years
Sheet-metal roof with underlay	approx. 30-35 years
Timber cladding (facade)	replacement approx. 40 years, repainting approx. every 20 years
Rendered facade	renovation approx. every 10 years
Brick facade	essentially never needs replacing
Windows	replacement approx. 40 years, repainting approx. every 10 years

A house’s load-bearing structure is designed for loads, such as snow and wind, that are exceeded on average once in 50 years. That is a safety margin and says nothing about when the structure needs replacing. The roof, facade and windows are the parts that usually need replacing while you own the house.

What to do with the figures

Find out roughly how old the big parts are, above all the roof, facade and windows. If something is near the end of its interval, it is not a red card, but it is a cost you want in your calculation and a good question for the agent (mäklare) or the surveyor (besiktningsman). That way it becomes something you expected rather than something that catches you out.