DATA-BACKED GUIDE · UPDATED JULY 2026
Are online trade cost guides accurate, and why real prices help
Search for the cost of almost any home job and you will find a dozen guides throwing out wide ranges that somehow never match your quote. Most are built from estimates, old figures or numbers supplied by the very firms doing the work. The real prices below take a different route, drawing on actual prices so you can see what people genuinely paid rather than a guess dressed up as data.
The quick version
- Many cost guides use estimates or supplier-provided figures, not proof of what was actually paid.
- Ranges are often so wide they tell you little, which suits the guide more than it suits you.
- Old figures linger online for years and quietly go out of date without being marked as such.
- Real prices show the price including VAT and the real conditions, which is far harder to spin.
What people actually paid
Real prices, in people's own words
- £45,000“Single storey 6.5m wide x 4m long (2022) peak inflation material costs. Included 4 keylite windows and 8ft bi fold. Gable roof. £45k”
- £51,816“Total cost £51,816 (give or take a couple of quid)”
- £80,000“We just finished a single storey. It was £2.5k per square meter plus VAT. Cost 80k in total”
- £95,000“Approx 95k, 5x3m. Included a new kitchen, downstairs WC, exterior power, knocking together upstairs bathroom & WC to make 1 room and unexpected new electrical works to most of the downstairs.”
- £95,000“Total cost £95k, of which build cost was £65k. Kitchen & utility £15k, flooring £3k, architect and planning £2k”
- £100,000“Our recent 2 storey side extension was upwards of £100k building costs.”
Genuine amounts posted publicly. We publish the price and the quote, never the person.
Why the price varies so much
Cost guides mislead for a few reasons that are worth understanding. First, plenty are built from estimates or from figures handed over by trades and manufacturers, who have little reason to quote low. Second, they lean on very broad ranges. A range that runs from small to enormous is technically always right, but it does nothing to help you judge your own quote. Third, they age badly. Material and labour prices move, yet an article written years ago keeps ranking and keeps quoting numbers that no longer hold. Fourth, they often gloss over what is actually included, so one figure might exclude VAT, access or waste removal while another includes the lot, and you are left comparing things that are not comparable. Price-based data sidesteps most of this. A real price reflects the true job, the real access, the actual materials and the 20% VAT most work carries, which is much harder to massage than a round-number estimate. That is why comparing your quote against genuine prices gives you a sharper read than a generic guide ever will.
How to pay less
- Treat any single online figure with caution and look for data based on real prices instead.
- When you compare quotes, check exactly what each includes, especially VAT, access and waste removal.
- Ignore very wide ranges. Focus on the median and the typical spread of what people actually paid.
- Use real prices to spot an outlier quote, then use that knowledge to negotiate or walk away.
Common questions
Why do online cost guides never match my quote?
Because many are built from estimates or supplier figures and use ranges so wide they fit almost anything. They also age without warning, so the numbers can be years out of date. Real price data, like the prices below, reflects what people genuinely paid recently.
How is price-based data different?
It comes from actual invoices and bills rather than guesses, so it captures the real job, the real materials and the 20% VAT most work carries. That makes it much harder to inflate or oversimplify than a round-number estimate on a generic guide.
How should I use cost data when checking a quote?
Compare like for like. Check what each quote includes, then measure it against the median and typical spread in the real prices below rather than a single headline figure. An outlier quote stands out quickly once you have a genuine benchmark.