What a quantity surveyor does,
and what they need from site.

A quantity surveyor manages the money on a construction job. They work out what it should cost, value what has been built, price every change and agree the final account. RICS calls them the cost managers of construction. On a contractor’s side the QS turns what happened on site into money, and every figure they produce rests on records made on site.

What does a quantity surveyor do?

The work follows the job from first budget to final account. A QS on a large project may cover one stage. In a trade firm, one QS often covers all of them across several jobs at once.

Building measurement follows the RICS New Rules of Measurement. NRM1 sets the rules for cost estimates and cost plans, and NRM2 for bills of quantities, which go on to value interim payments and varied work.

Client QS and contractor QS

There are two sides to the job. A consultant quantity surveyor, often called a PQS, works for the client. They set the budget, run the procurement and value the work for the contract administrator, who certifies what the contractor is paid.

A contractor’s quantity surveyor works for the firm doing the work. They price it, apply for payment, manage subcontractors’ accounts and report whether each job is making money. Senior contractor QSs are often called commercial managers. Both sides can be chartered through RICS, and both value the same work from opposite ends.

The monthly valuation

Most UK construction work is valued monthly. RICS guidance on interim valuations sets out how it is done, and three of its points shape what the QS needs:

• The whole job is revalued each time, not just the work done since the last valuation.
• Work is valued as properly executed, and a site visit, with inspection or measurement, checks that it has been done. Whether it was done properly is for the contract administrator.
• Variations go in under a written instruction, and a daywork sheet signed and dated by authorised people is a record the QS does not second-guess.

Materials count once they are delivered to or beside the works, protected and not brought early. RICS treats a valuation within 5% of the true figure as acceptable on contracts up to £2.5m, and within 2.5% above that.

A valuation is only as good as the last record from site. The QS can measure the work, but cannot measure what nobody wrote down.

Cost value reconciliation

On the contractor’s side, the monthly valuation has a twin. Cost value reconciliation, or CVR, compares the value of the work with the cost of doing it, job by job, at each month end. RICS describes it as the project’s profit and loss statement, including costs for goods and services used but not yet paid for.

The gap between what was applied for and what the work is worth is called over or under measure. A job that looks profitable on applications and loses money on cost is found here, or not at all. How to run a cost value reconciliation.

The four things a QS needs from site

Most of the friction between the office and the job comes down to four records. When they arrive complete and on time, the QS spends the month valuing. When they do not, the QS spends it chasing.

• Progress, dated and located. What is complete, where on the job, and on what date. Photographs help when they carry the date and the area. RICS practice information suggests annotating them with the date and time.
• Every instruction, written down the day it is given. An instruction on the slab is worth nothing at valuation unless it is in writing. RICS practice information suggests numbering every change on a register, updated at least monthly.
• Daywork sheets signed that week. Once a sheet is signed and dated by authorised people, the QS cannot replace it with their own estimate. Without one, the work is measured or valued fairly, and that is where the argument starts.
• Labour, plant and materials against the right job. Hours, deliveries and plant on hire, booked to the job that used them. Without it, the cost side of CVR is a guess, and so is every rate in the next tender.

Why the record has to be made at the time

The Society of Construction Law’s Delay and Disruption Protocol is direct about it. Records of progress, delay and disruption must be made as the works progress, not afterwards. They should state facts, offer no opinions and, where practicable, be signed by both sides.

Its list of useful records reads like a site manager’s day. It names daily site reports with weather, labour, deliveries, hours and plant, and dated progress photographs. It adds daily labour and plant allocation, a log of major deliveries, and timesheets. A QS assembling a claim from memory is working against all of it. More on that in getting paid for variations you were told to get on with.

How to become a quantity surveyor

Most quantity surveyors qualify through a degree accredited by RICS, a graduate scheme or the Level 6 Chartered Surveyor degree apprenticeship. Chartership, as MRICS, comes through the RICS Assessment of Professional Competence, which usually takes around two years after the degree.

The National Careers Service gives a salary range of £26,000 for a starter to £70,000 for an experienced QS, for 37 to 40 hours a week. Contractors, consultancies, developers, housing associations, local authorities and specialist contractors all employ them.

RICS publishes the valuation, change and commercial management documents cited here as practice information, which is advisory, and has said new UK practice guidance will replace them. This article follows the versions in force on 30 October 2026.