Replacing windows – choose the right windows and fitter

What replacing windows involves

Replacing windows involves removing the old windows, adapting the opening, fitting and packing the new windows, sealing against moisture and air, and fitting external window sills as well as internal architraves and reveals.

An alternative to replacement is restoring the existing windows or adding an insulating pane. In older houses with fine original windows this can be the better choice, both financially and for the character of the house. Feel free to ask the company about both options.

What affects the price?

The number and size of the windows are obviously decisive, but there are other factors. Ask for quotes and compare:

• Window type – fixed, side-hung, pivot window or French door.
• Material – timber, timber/aluminium or PVC, with different maintenance needs.
• Energy performance, measured as the U-value.
• Sound-reducing or safety glass.
• Whether the windows are high up and require scaffolding or a lift.
• How much of the reveals, architraves and façade need making good afterwards.

Choosing windows

A lower U-value means less heat escapes. For homes that are actively heated it is often worth choosing energy-efficient windows, especially in north-facing rooms. Also consider how the windows will open and be cleaned, what view you want and whether they should suit the style of the house.

Do not measure and order yourself – let the company that will fit the windows measure the openings. Then the responsibility for making sure the windows fit lies with them.

Also plan for the day of the replacement. Furniture and curtains near the windows need moving, and there will be dust when the old windows are taken out. If many windows are replaced at once in winter, the house can get cold for a few hours, so ask the fitter how many windows they replace at a time and how they protect the rooms.

Building permits and rules

If you replace the windows with ones that look the same, no building permit is normally required. If you change the windows' appearance, size, glazing bars or colour, a permit may be required, particularly within an area covered by a detailed development plan or if the house is of cultural or historical value. Contact the municipal building committee. If you live in a housing cooperative flat, the windows are often owned by the cooperative, so ask the board first.

Also check whether escape through a window is needed in bedrooms. Ask the fitter whether the new windows meet the requirements for your room.

ROT tax deduction

The labour cost of replacing windows in your home normally qualifies for the ROT deduction of 30 %. The windows themselves and other materials do not qualify. The deduction is capped at SEK 50,000 in ROT per person per year, within the overall cap of SEK 75,000 for ROT and RUT combined. Check that the quote lists labour and materials separately.

What the quote should include

• Number of windows, sizes, opening function, brand and U-value.
• Whether measuring is included and who is responsible for the measurements.
• Removal, disposal and recycling of the old windows.
• Sealing, packing, window sills, architraves and reveals.
• Any scaffolding or lift.
• Labour and materials listed separately plus the estimated ROT deduction.
• Delivery time, installation time and warranties.

Questions to ask and common mistakes

Ask how they seal between the window and the wall, whether they follow the manufacturer's installation instructions and how they deal with lead or asbestos in old putty and paint on older windows. Also ask how long the rooms will be open during the replacement, especially in winter.

Common mistakes include windows fitted with poor sealing so that there are draughts or moisture damage, forgetting window sills and reveals in the quote, and choosing windows on price alone without comparing U-value and quality.

Getting quotes via Fixtorget

State the number of windows and approximate sizes, and upload photos, when you describe the job on Fixtorget. Up to four vetted companies can contact you and you can compare them at your own pace. Every company has had its F-tax and VAT registration checked, and reviews can only be left by customers who have been in contact via Fixtorget.

Frequently asked questions