Windows: lifespan and cost

Windows are both an upkeep and an energy question. The table shows how long different windows last and what a replacement usually costs per window.

The ranges apply to a normal-sized house. Actual cost depends on size, access and region. Lifespan means technical lifespan with normal upkeep.

Component	Lifespan	Replacement cost
Wooden windows	50 yrs (40-60)	100 000-300 000 kr
Wood-aluminium windows	45 yrs (40-50)	120 000-350 000 kr
PVC windows	37 yrs (35-40)	80 000-250 000 kr
Insulated glazing units	25 yrs (20-30)	30 000-100 000 kr

How long does a window last?

A well-maintained wooden window can last a very long time, longer than many modern windows, because it can be renovated piece by piece. PVC and wood-aluminium windows need less care but cannot be repaired the same way once they are spent. The insulated glazing units in the window have their own, shorter life and may need replacing even when the frame is sound.

What does replacing windows cost?

The price is usually per window and depends on size, type and whether the whole frame is replaced or only the glass. Replacing every window in a house at once is a large item, but often lowers heating costs. The cost in the table is for one normal-sized window, fitted.

What the age of the house tells you

Some build years carry known risks for exactly these parts. Here are the most common ones.

PCB in sealants Houses built 1956–1973

PCB in sealants around windows, doors and balconies, and between concrete elements. An environmental and health risk. Legal requirement: survey by 2008 at the latest, remediation when above 500 mg/kg.

Energy-hungry construction Houses built 1900–1975

Poor insulation, single-glazed windows, a leaky building envelope. Check the energy performance certificate and the running costs.

Is it worth renovating old windows instead of replacing?

Often yes, if the timber is sound. Older windows in heartwood are made to be re-puttied and painted, and a renovation is cheaper than new. If the frames are rotten, replacement pays off better.

What does condensation between the panes mean?

Condensation inside a sealed unit means it has failed and lost its insulating gas. The unit then needs replacing. It says nothing about the frame, which can be perfectly fine.