Builder Cost Calculator UK
Estimate the 2026 cost of your building project — by job type, finish level and where you are in the UK. Instant result, no email needed.
Estimate Your Builder Costs
4 steps. Labour + materials, excluding VAT. Always get three like-for-like written quotes before you commit.
How This Calculator Works
We combine project type with finish level, then apply a regional labour multiplier from 2026 UK builder quotes.
Project + finish level (labour + materials)
- Small repairs — £1,800 base
- Single room refurb — £7,500 base
- Kitchen/bathroom (build work) — £6,500 base
- Structural knock-through — £7,000 base (incl. steel)
- Single-storey extension — £34,000 base · Loft/garage conversion — £24,000 base
- Whole-house renovation — £55,000 base
- Standard ×1.00 · High-end ×1.40 · Premium ×1.90
Labour + materials excluding VAT. Builder day rate typically £150–£250 (£100–£150 for a labourer); most turnover-above-£90k builders add 20% VAT.
Regional Multipliers
- London 1.28× · South East 1.14× · South West 1.05×
- East of England 1.08× · Midlands 1.00× (baseline)
- North West 0.93× · North / Yorkshire 0.92×
- Wales 0.94× · Scotland 0.96× · NI 0.88×
Low/high band is ±20% around the mid estimate. A firm price follows a site survey.
Typical Builder Costs by Project (2026)
Labour + materials (excl. VAT) by project, Midlands baseline (±20% band).
| Project | Typical 2026 cost | Notes |
|---|---|---|
| Small repairs / odd jobs | £800–£3,000 | A few days on site |
| Single room refurbishment | £4,500–£12,000 | 1–2 weeks |
| Structural knock-through (incl. steel) | £1,800–£4,000 | Wall + steel + calcs |
| Single-storey extension (build) | £28,000–£45,000+ | 8–14 weeks |
| Whole-house renovation | £40,000–£120,000+ | Highly variable |
These figures power the calculator above — enter your own spec for a tailored estimate. For the full breakdown, read our complete cost guide.
What drives the cost of a building project
On a building job the base cost is really just the starting point, because the same project can double depending on scope and finish. A single-room refurbishment done to a standard spec is one number; take it to a high-end or premium finish — better joinery, tiling, glazing and fittings — and the labour and materials climb steeply, which is why the calculator applies a finish multiplier. Structural work is its own line: knocking through, underpinning or adding steel brings in a structural engineer and building control, and older properties routinely hide problems — poor foundations, dated wiring, damp or rot — that only surface once work starts.
That is why a sensible quote carries a contingency, and why the professional fees around the build matter as much as the build itself. Design and drawings, a structural engineer, planning and building-control fees and any party-wall agreement usually sit outside the builder’s price, so check them separately. VAT applies once a builder’s turnover passes the £90,000 threshold, though some work — a new build, or a home empty for over two years — can qualify for a reduced or zero rate. Labour rates also run well above the Midlands baseline in London and the South East. Our builder cost guide shows what a fair 2026 quote looks like line by line, the house renovation cost guide covers whole-property projects, and you can compare vetted local builders through our find a builder hub.
Frequently Asked Questions
How much does a builder cost per day in 2026?
Do builders charge a day rate or a fixed price?
How much does a builder cost for a full house renovation?
What is included in a builder's price?
Does a builder charge VAT?
How accurate is this builder cost calculator?
What does the builder estimate include and exclude?
Why might a builder quote differ from the calculator?
How much deposit should I pay a builder?
How do I compare builder quotes fairly?
Do I need planning permission and building control for building work?
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