Line-by-line build-up
Materials = supply cost; labour = what the trade charges for that element; fees & prelims = design, Building Control, party wall, scaffold, skips and site costs. Ranges are typical 2026 UK figures outside London. Every line links to the guide that explains it; labour figures assume the day rates in the Cost Index.
| Element | Materials | Labour | Fees & prelims | Notes |
|---|---|---|---|---|
| Design, Building Control & project managementindex ↗ | – | – | £3,000–£7,000 | Drawings where walls move; Building Notice for services |
| Strip-out, skips & making safeindex ↗ | – | – | £2,500–£4,500 | 4–8 skips; asbestos survey on pre-2000 homes |
| Structural alterations (knock-through + steel)index ↗ | £800–£1,900 | £2,000–£4,800 | – | One load-bearing wall removed |
| Full rewire (3-bed)index ↗ | £1,500–£2,500 | £3,500–£5,500 | – | New consumer unit, all circuits, Part P certificate |
| Replumb & new boiler/heatingindex ↗ | £2,100–£3,700 | £4,400–£7,800 | – | Combi boiler supply & fit £1,800–£3,500 within this |
| Replastering throughoutindex ↗ | £1,450–£2,550 | £5,050–£8,950 | – | Skim £15–£25/m²; full re-board where walls are shot |
| New kitchen (mid-range)index ↗ | £7,800–£16,750 | £4,000–£7,000 | – | Full fit incl. plumbing, electrics, tiling, worktop template |
| New bathroom (mid-range)index ↗ | £3,150–£5,400 | £3,850–£6,600 | – | |
| Windows (replace 8–10)index ↗ | £3,950–£8,650 | £1,550–£3,350 | – | uPVC–timber range, FENSA |
| Internal doors, skirting, architraveindex ↗ | £1,200–£2,600 | £1,800–£3,900 | – | |
| Flooring throughoutindex ↗ | £2,500–£5,500 | £2,000–£4,500 | – | |
| Decoration throughoutindex ↗ | £750–£1,400 | £2,550–£4,900 | – | £150–£400 per room standard repaint |
| Insulation upgrades (loft top-up, draught-proofing)index ↗ | £350–£950 | £550–£1,450 | – | |
| Sub-totals (42% / 49% / 9%) | £25,550–£51,900 | £31,250–£58,750 | £5,500–£11,500 | |
| Build-up total | £62,300–£122,150 | vs published guide range £62,000–£122,000 | ||
The published guide for this job quotes £62,000–£122,000, which is the figure the build-up above is reconciled against.
Common additions & variations
- Light cosmetic refresh instead, £650–£900 per m²
- Sequence of works (what order to do it in), guide
- London / period property uplift, see guide
How to use this
Treat the build-up as a sanity check on quotes, not a price list: a builder's quote that lands inside the total range with a similar materials/labour split is priced normally; one far below it is usually missing scope. Get three itemised quotes, compare them line by line against this table, and ask about anything that's absent. Figures exclude VAT where the trade is VAT-registered (most are above ~£90k turnover), and exclude fees you pay directly such as planning application fees.
Other build-ups
- Loft conversion, £45,000–£65,000
- Ground floor extension, £36,000–£56,000
- Double storey extension, £80,000–£120,000