Quantity Surveying·9 min read·18 February 2025

What Is a Quantity Surveyor and What Do They Do?

Quantity surveyors are the financial managers of the construction industry. Here's what they do, why they're valuable, and when you might need one.

AW
Adam Whitehouse
AssocRICS, MCIArb, MCIOB · RICS Registered Valuer

Ask most people what a quantity surveyor does and you'll get a blank look or a vague answer about measuring things on building sites. It's one of the most misunderstood professions in the UK — and one of the most valuable in construction. This guide explains what quantity surveyors actually do, why they matter, and when you need one.

The Simple Answer

A quantity surveyor (QS) is a construction cost specialist. Their primary job is to manage the financial and contractual aspects of construction projects — from estimating costs before a project starts to settling accounts when it ends.

Think of a QS as the financial manager of a building project. Just as a company needs a finance director to manage its money, a construction project needs a quantity surveyor to manage its budget.

What Quantity Surveyors Do: The Full Picture

The scope of a quantity surveyor's work covers the entire lifecycle of a construction project:

Before construction starts:

  • Advising on construction costs at feasibility stage
  • Producing cost plans and budgets
  • Preparing bills of quantities and tender documents
  • Advising on procurement strategy (how to appoint a contractor)
  • Reviewing and comparing tender submissions
  • During construction:

  • Assessing and certifying contractor payment applications
  • Valuing change orders and variations to the contract
  • Monitoring costs against budget
  • Advising on contract disputes and claims
  • Producing monthly cost reports for the client
  • After construction:

  • Agreeing the final account with the contractor
  • Releasing retention
  • Advising on defects and any associated cost deductions
  • Providing cost data for future projects
  • Types of Quantity Surveyor

    There are two main types of quantity surveyor in the UK:

    Client-side QS (PQS – Professional Quantity Surveyor): Works on behalf of the building owner. Their job is to protect the client's budget, ensure the contractor is paid correctly, and manage the financial risk on the project. This is what Volarex does.

    Contractor's QS: Works for the building contractor. Their job is to maximise the contractor's commercial position — pursuing claims, managing subcontractor costs, and ensuring the contractor is paid what it is owed.

    Both types need to understand construction law, measurement, and cost analysis — but their commercial loyalties are different.

    RICS Qualification

    The gold standard for quantity surveyors in the UK is RICS membership. The Royal Institution of Chartered Surveyors sets the standards for professional practice, ethics, and continuing development.

    At Volarex, Adam Whitehouse holds the AssocRICS designation, along with MCIOB (Member of the Chartered Institute of Building) and MCIArb (Member of the Chartered Institute of Arbitrators) — a combination of qualifications that reflects deep expertise in construction management, costs, and dispute resolution.

    When Do You Need a Quantity Surveyor?

    You should consider engaging a quantity surveyor if:

  • You're a developer planning a construction project of any scale
  • You're a building owner and want to understand what your project will really cost
  • You're uncertain about a contractor's payment application or final account
  • You've received a contractor's claim and need independent assessment
  • You're in a construction dispute and need expert quantum analysis
  • You need someone to manage your tender process professionally
  • Many private individuals and small developers underestimate the value of a QS, then find themselves in costly disputes or over-budget situations that independent cost management could have prevented.

    Quantity Surveying vs Quantity Surveyor vs Estimator

    These terms are sometimes used interchangeably but have distinct meanings:

  • **Quantity surveyor:** A qualified professional managing all financial and contractual aspects of a project
  • **Estimator:** Focused specifically on producing cost estimates (often contractor-side)
  • **Cost manager:** Another term for a client-side quantity surveyor, commonly used in large projects
  • At Volarex, we cover all of these functions — providing estimating, cost planning, and full QS services as required.

    How Much Does a Quantity Surveyor Cost?

    QS fees are typically calculated as a percentage of the project value (0.5%–3% depending on project size and scope) or on a time-charge basis. For specific pieces of work (such as a bill of quantities or final account), fixed fees are often agreed.

    Contact Volarex for a no-obligation discussion about your project and we'll provide a clear fee proposal.

    AW
    Adam Whitehouse
    AssocRICS · MCIArb · MCIOB · RICS Registered Valuer

    Founder of Volarex, with over 20 years' experience in residential surveying and commercial quantity surveying. Adam provides RICS home surveys across Yorkshire and the UK, and full QS services for developers and contractors.

    About Adam →

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