What does a quantity surveyor cost in the UK?
Quantity surveyor fees for domestic projects in the UK typically fall into two models:
Percentage-based: 1–3% of the total project construction cost. On a £150,000 extension and loft project, this means £1,500–£4,500 in QS fees.
Fixed fee: £800–£6,000+ for domestic residential projects, depending on complexity, scope, and what services are included.
What a QS does for domestic projects
Pre-contract services
- Cost planning: establishing a realistic budget before committing to design
- Cost estimation: detailed cost plan based on drawings and specification
- Value engineering: identifying where specification can be adjusted to improve value without compromising quality
- Tender management: preparing bills of quantities, issuing to contractors, evaluating returns, recommending award
During construction
- Interim valuations: checking contractor applications and certifying the correct amount for each payment stage
- Variation assessment: pricing changes to scope as they arise
- Final account agreement: agreeing the final total with the contractor
Fixed-fee QS services for domestic projects
| Service | Typical cost |
|---|---|
| Ballpark estimate (phone/online) | £150–£400 |
| Detailed cost estimate from drawings | £500–£1,500 |
| Tender documents and bills of quantities | £1,500–£3,500 |
| Full pre-contract QS service | £2,000–£6,000 |
| Interim valuations (per visit) | £350–£700 per visit |
When is a QS worth it for a domestic project?
A QS provides clearest value when: the project is above £80,000–£100,000; you are using a traditional procurement route and need to evaluate competitive tenders properly; you need objective, professionally prepared figures before approaching contractors; the project involves significant complexity, unknowns, or structural elements; you are managing the project yourself without a main contractor.
The difference between an estimate and a QS
A contractor estimate is prepared by someone with a financial interest in winning the work. A QS estimate is prepared by an independent professional with no stake in who is appointed. This independence matters most when evaluating multiple tenders, when the project is large enough that errors are costly, and when client-contractor disputes are more likely.