Why one quote is never enough: the jobs where prices swing most
On the 150 UK home-improvement jobs Costwise tracks, the same job name can hide an enormous price range. A painting and decorating runs from £150 to £5,000, a 33× swing, and 19 jobs vary by ten times or more. That is why a headline price or a single quote tells you little until you pin down the spec, and why it pays to get three.
The widest price ranges
The jobs whose top guide price is the biggest multiple of their lowest, 2026. The range spans the smallest, simplest version of the job to the largest and most complex, so the spec, not the tradesperson, is usually what moves it.
| Job | From | Up to | Range |
|---|---|---|---|
| Painting and decorating | £150 | £5,000 | 33× |
| Swimming pool | £3,000 | £100,000 | 33× |
| Asbestos removal | £200 | £6,000 | 30× |
| Subsidence repair | £2,000 | £50,000 | 25× |
| Tree removal | £150 | £3,000 | 20× |
| Party wall agreement | £150 | £2,500 | 17× |
| Japanese knotweed removal | £1,000 | £15,000 | 15× |
| Basement conversion | £10,000 | £150,000 | 15× |
| Roof repair | £150 | £2,000 | 13× |
| Pergola | £900 | £12,000 | 13× |
| Damp proofing | £500 | £6,500 | 13× |
| Kitchen island | £500 | £6,000 | 12× |
Where you can overpay by the most
By cash rather than multiple: the whole-project jobs with the widest gap in pounds between a simple and a complex version. These are where getting it wrong costs the most.
| Job | From | Up to | Gap |
|---|---|---|---|
| Basement conversion | £10,000 | £150,000 | £140,000 |
| Granny annexe | £30,000 | £150,000 | £120,000 |
| Swimming pool | £3,000 | £100,000 | £97,000 |
| Underpinning | £5,000 | £60,000 | £55,000 |
| Loft conversion | £22,000 | £75,000 | £53,000 |
| Subsidence repair | £2,000 | £50,000 | £48,000 |
| Orangery | £15,000 | £60,000 | £45,000 |
| New kitchen | £5,000 | £40,000 | £35,000 |
Key statistics
- According to Costwise, reviewed June 2026, painting and decorating has the widest price range of the 150 UK jobs it tracks: £150 to £5,000, a 33× swing depending on scope and spec.
- The biggest cash gap on a single job is a basement conversion, about £10,000 at the simplest to £150,000 at the most complex, a £140,000 range (Costwise, reviewed June 2026).
- Costwise data (2026) shows 19 of 150 home-improvement jobs have a top price at least ten times their lowest, and 60 at least five times, which is why a single quote cannot tell you if a price is fair.
How to use this before you get a quote
- Get three quotes on anything with a wide range. On these jobs a single number is impossible to sanity-check.
- Write down the exact spec first, the size, materials and finish, and give every installer the same brief so their prices are actually comparable.
- Know the published range before you call. If a quote sits near the top of the band, ask what about your job justifies it.
- Take extra care on specialist work like a basement conversion, underpinning or Japanese knotweed removal, where the range is widest and you are least able to judge a fair price yourself.
Common questions
Why do quotes for the same job vary so much?
Because the job name hides the spec. Costwise found a painting and decorating ranges from £150 to £5,000, a 33× swing, and 19 of the 150 jobs it tracks vary tenfold or more. Size, materials, finish, access and region all move the price, so two honest quotes for what sounds like the same job can be far apart.
How many quotes should I get for home improvement work?
At least three, especially on any job with a wide range. Costwise data shows 60 of 150 jobs vary fivefold or more from low to high, so a single number is impossible to sanity-check on its own. Give every installer the same written spec so their prices are actually comparable.
How do I know if a quote is fair?
Know the published range before you call. If a quote sits near the top of the band, ask what about your job justifies it; if it is well below, ask what has been left out. Take extra care on specialist work like a basement conversion or underpinning, where the range is widest and a fair price is hardest to judge yourself.
These are independent Costwise guide-price ranges, reviewed June 2026, reflecting how much each job varies by size, specification, complexity and region. They are not a survey of competing quotes from firms, but that is the point: without the range, you cannot tell a fair quote from a high one. Figures match our individual guide pages. Free to cite with a link to https://costwiseuk.co.uk.