Replacing every window in the house is a big job and a big spend, so it makes sense to know the numbers before you start. If you are wondering how much to replace windows in a house, the honest answer is that it depends on the property size, the material and the state of your openings. This guide gives realistic 2026 ranges and, just as usefully, shows how to phase the work so it does not all land at once.
How much to replace windows in a house, by property size
The clearest way to picture the cost is by property size, in uPVC, supplied and fitted. As a broad 2026 guide:
- A flat or small terrace (around 4 to 6 windows) often costs around 2,500 to 5,000 pounds.
- A mid-terrace or small semi (around 6 to 8 windows) tends to land around 3,500 to 7,000 pounds.
- A larger semi-detached (around 8 to 10 windows) commonly runs around 5,000 to 9,500 pounds.
- A detached house (10 windows and up) can be 8,000 to 16,000 pounds or more.
These are for a full uPVC replacement. Aluminium and timber cost more, and a period property with bays, arches or leaded glass sits higher again. You can see the styles behind these figures in our uPVC window range.
What moves the number
Two houses with the same window count can still price differently. Here is why.
The material
uPVC is the most affordable and the most common. Aluminium costs more but offers slim frames and a sharp modern look. Timber suits period and conservation homes but is the priciest to buy and maintain. Your choice can shift the whole-house total by thousands.
Window style and size
Bay windows, large picture windows and anything shaped or arched cost more than a standard casement. A house with several bays will price higher than one with plain openings, even at the same count.
The glass
Standard energy-efficient double glazing is the baseline. Triple glazing, acoustic glass for a noisy road, or toughened safety glass where it is required all add to the total.
The state of the openings
If an installer takes out the old windows and finds rotten timber, crumbling sills or damaged reveals, putting that right adds to the job. A good survey should flag this before you commit, so there are no nasty surprises.
Phasing the work to spread the cost
Here is the part that genuinely helps if the full figure feels steep: you do not have to do every window at once.
Replacing the house in stages is completely sensible, and plenty of people do it. A few honest ways to phase:
- Start with the worst offenders. Do the draughtiest, most rotten or most misted windows first, so your money fixes the real problems.
- Do the coldest rooms first. The north-facing bedroom or the room you use most gets the early benefit.
- Work floor by floor, or front then back, so each phase is a tidy, self-contained job.
- Match the spec across phases, so the windows all look the same once the house is finished. Note down the exact frame colour, glass and style for later.
The one trade-off is that doing them in batches usually costs a little more per window than doing the lot in one visit, because each visit has its own set-up. For many households, spreading the cost is worth that small premium.
Repair or replace?
Before committing to a whole-house replacement, it is worth being honest about which windows genuinely need it. If most are sound and only one or two have a misted pane, a stuck hinge or a broken lock, a repair is far cheaper than replacement. We handle those window and door repairs too, and we will always tell you when a fix beats a full swap.
The only way to get your real figure is a measured survey. Request a free quote and we will price the whole house, or a first phase, with no pressure.
FAQs
How much does it cost to replace all the windows in a house in 2026?
As a rough 2026 guide in uPVC, a small terrace is around 2,500 to 5,000 pounds, a semi around 5,000 to 9,500 pounds, and a detached house 8,000 to 16,000 pounds or more. Aluminium and timber cost more. Get a survey for an accurate figure.
Can I replace my windows a few at a time?
Yes, and many people do. Phasing the work lets you spread the cost, starting with the draughtiest or most-used rooms. Just record the exact spec so later windows match, and expect a small premium per window compared with doing them all at once.
Which windows should I replace first?
Start with the ones causing real problems: single glazed, rotten, badly draughty or misted windows, and the coldest rooms you use most. That way your first spend delivers the biggest improvement in comfort and running costs.
Does replacing all the windows add value to my home?
It can. Fresh, efficient windows improve how a house looks and feels and make it easier to sell, particularly on a period property where sympathetic windows matter. They will not always return their full cost, but they help the sale and you enjoy the comfort meanwhile.
Do new windows need to meet Building Regulations?
Yes. Replacement windows must meet current standards for energy efficiency and safety, and the work is usually registered under a scheme like FENSA. Rules change, so a reputable installer will handle the certification and you can check current requirements with your local authority.
Want to see the styles and finishes before you plan the job? Download our latest brochure, or request a free quote and we will price your home honestly.