A quantity surveyor (QS) is a chartered professional who manages the financial and contractual aspects of construction projects. They are the cost experts of the building industry - producing budgets, preparing tender documents, valuing work in progress and settling final accounts. On larger projects they work alongside the architect and project manager as an independent check on contractor costs and a safeguard against budget overruns. In the UK, the primary qualification is MRICS (Member of the Royal Institution of Chartered Surveyors) through the quantity surveying pathway. A quantity surveyor may work for the employer (client-side) or for the contractor, but both roles require the same technical expertise.
What they do
- Prepare initial cost plans and budget estimates from design information
- Produce bills of quantities measuring all elements of construction work
- Prepare tender documents and manage the competitive tender process
- Analyse tenders received and make contractor appointment recommendations
- Value work in progress and issue interim payment certificates
- Assess and negotiate variations and contractor cost claims
- Agree the final account with the contractor at practical completion
- Advise on procurement routes, contract selection and risk allocation
When you need one
A quantity surveyor adds most value on projects where costs are complex, competition for contractor work is important, or where disputes about money are likely. Below are the key trigger points.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| Budget estimate / cost plan | £500 - £1,500 |
| Bills of quantities | £1,500 - £5,000+ |
| Tender analysis and report | £600 - £1,500 |
| Employer's agent fee | % of contract value |
| Final account agreement | £800 - £2,500 |
| Hourly rate | £80 - £150 / hr |
QS fees on larger projects are often quoted as a percentage of construction cost - typically 1.5-3% for a full professional service. London rates are typically 20-30% higher. Always clarify whether the fee covers tender management, site valuations and final account.
Qualifications to look for
The primary qualification for quantity surveyors in the UK. Requires a RICS-accredited degree in quantity surveying or a conversion route, plus the APC (Assessment of Professional Competence) covering cost management, procurement and contract administration. Verify at rics.org.
Some quantity surveyors also hold CIOB membership, particularly those with a strong site and construction management background. MCIOB indicates competence in construction operations alongside cost management skills.
The structured training and assessment programme that leads to MRICS. Graduate quantity surveyors work through a structured logbook covering technical competencies including cost planning, procurement and contract practice, before sitting the final professional review.
How to find a reputable quantity surveyor
Frequently asked questions
What does a quantity surveyor actually do?
A quantity surveyor (QS) manages the financial and contractual side of a construction project. They prepare cost estimates and budgets, produce bills of quantities for tendering, evaluate tenders from contractors, value work in progress for payment certificates, negotiate and agree the final account, and advise on contract disputes and claims. On larger projects they work alongside the architect and project manager as part of the professional team.
Do I need a quantity surveyor for a house extension?
For small domestic extensions most homeowners manage costs without a QS, relying on builder quotes and an architect's approximate cost advice. However, if your project is over £100,000, involves tendering to multiple contractors, or you are concerned about cost control and final account settlement, a QS adds real value. They can prepare a proper specification and tender pack that allows like-for-like comparison of contractor quotes and identifies scope gaps before work starts.
What is the difference between a quantity surveyor and a project manager?
A quantity surveyor focuses specifically on financial and contractual management - costs, tenders, valuations and the final account. A project manager controls the overall delivery of the project - programme, quality, contractor coordination and client communication. On larger projects both are appointed; on smaller projects a building surveyor or project manager with cost management skills may combine both roles.