Quantity Surveying·6 min read·28 January 2025

Quantity Surveyor vs Architect: What's the Difference?

Many clients are unsure about the difference between an architect and a quantity surveyor. Here's a clear guide to each profession's role and when you need which.

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Adam Whitehouse
AssocRICS, MCIArb, MCIOB · RICS Registered Valuer

If you're planning a construction project for the first time, the various professional roles can be confusing. Architects, quantity surveyors, structural engineers, project managers, and building surveyors all have distinct but sometimes overlapping roles. This guide focuses on the difference between an architect and a quantity surveyor — two of the most important professionals on any construction project.

What Does an Architect Do?

An architect is responsible for the design of a building. Their primary role is to translate the client's brief into a buildable design that meets aesthetic, functional, planning, and regulatory requirements.

Key architect responsibilities:

  • Developing the design concept and working drawings
  • Obtaining planning permission and building regulations approval
  • Specifying materials, finishes, and building systems
  • Acting as contract administrator (certifying payments, issuing variation instructions) on traditional contracts
  • Ensuring the design meets legal, regulatory, and accessibility requirements
  • Architects are registered with the Architects Registration Board (ARB) and typically also members of the Royal Institute of British Architects (RIBA).

    What Does a Quantity Surveyor Do?

    A quantity surveyor is responsible for the financial and contractual management of a construction project. Their primary role is to ensure the project is delivered within budget and that the contractual relationship between client and contractor is properly managed.

    Key quantity surveyor responsibilities:

  • Producing cost plans and budget estimates at each design stage
  • Preparing bills of quantities and tender documents
  • Managing the tender process
  • Administering the contract commercially (valuations, variations, claims)
  • Producing monthly cost reports
  • Agreeing the final account
  • Quantity surveyors are typically members of RICS (Royal Institution of Chartered Surveyors) or CIOB (Chartered Institute of Building).

    How They Work Together

    On a traditionally procured project, the architect and quantity surveyor work alongside each other throughout the project:

  • The architect develops the design; the QS costs it
  • The architect issues variation instructions; the QS values them
  • The architect issues payment certificates; the QS provides the valuation
  • The architect issues practical completion and defects certificates; the QS manages the financial implications
  • Both professionals report to the client and work in the client's interest, but from different perspectives — the architect's focus is design and construction quality; the QS's focus is cost and contractual compliance.

    Do You Always Need Both?

    Not always. For small projects:

  • A builder working directly with a homeowner may not require either professional
  • A simple kitchen extension might be designed by the builder or a designer, without a QS
  • However, for any project above around £100,000 in value, engaging a QS is almost always worthwhile. The cost savings from competitive tendering, cost control, and final account management typically far outweigh the QS fee.

    For projects above £500,000, engaging both an architect and a QS (alongside structural and services engineers) is strongly recommended.

    Do You Need an Architect if You Have a QS?

    Yes — these are complementary, not interchangeable, roles. A quantity surveyor cannot design your building and is not qualified to obtain planning permission. Equally, an architect typically does not have the specialist commercial and contractual knowledge of a quantity surveyor.

    Some multi-disciplinary firms offer both architectural and QS services. However, for full independence, many clients prefer to appoint an architect and QS separately — ensuring each professional independently represents the client's interest in their respective domain.

    Volarex: Your Independent Quantity Surveyor

    Volarex provides quantity surveying services alongside (not instead of) your architect. We work collaboratively with design teams, bringing commercial rigour to complement design expertise. Whether you already have an architect or are still assembling your professional team, contact us to discuss how we can add value to your project.

    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 →

    Have a Specific Question?

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