Source: https://www.quantsurv.com/library/glossary/quantity-surveyor Content format: Markdown version of the public page. Content reviewed: 2026-10-15 # What is a quantity surveyor? A quantity surveyor is a construction professional who advises on and manages the costs and commercial aspects of a project. by [Jack Butler-Kettle]() · About 3 min readShare ## Further detail Read this alongside [RICS explanation of the quantity surveyor role](). A quantity surveyor, often shortened to QS, is a construction professional concerned with the cost and commercial management of building and infrastructure work. Quantity surveying is the discipline; the quantity surveyor is the person carrying it out. The role connects the scope of the work to its price, payment and financial consequences. The [RICS introduction to quantity surveying]() describes cost planning, procurement, tendering and commercial management as areas of the profession. A QS may specialise in one area or provide support across a project. A detailed account of the tasks and documents belongs on the separate page, [what does a quantity surveyor do?](). ### Who do they work for? A client's or consultant QS advises the person commissioning the construction work. A contractor's QS works on the contractor's commercial position, and a subcontractor's QS concentrates on the relevant trade package and account. A freelance QS can be appointed by any of these parties. Being external to a business does not mean acting as a neutral decision-maker between both sides. For a main contractor, the QS may sit within a wider commercial team. Agree the represented party, scope and any conflicts before the work begins. ### How does the role differ from other professions? The principal focus is different. Quantity surveying concerns construction cost and commercial matters; a building-condition survey examines the property and its condition. A topographical or measured survey records physical features and dimensions. The word surveyor does not make these appointments interchangeable. Likewise, estimating is part of the wider cost discipline, whereas a QS appointment may continue into payment, change and closing-account work. An architect, project manager or contract administrator has a different appointed role, even where one person is qualified and engaged to perform more than one function. The [construction adviser comparison]() helps distinguish the support needed. ### What qualifications and expertise should you check? Do not assume chartered status from the words quantity surveyor. Ask about the individual's qualifications, relevant experience, professional membership and the work they will actually undertake. Verify any claimed membership or regulated-firm status through the relevant professional body's records. A qualification and a clear appointment answer different questions: competence for the work and responsibility for the deliverable. ### When might you need one? Useful triggers include an uncertain budget, prices based on different scopes, substantial changes, payment requests that need checking or a closing account that does not reconcile. The appointment can address one decision or a continuing commercial role. The [guide to choosing a quantity surveyor]() explains how to define that need and compare proposed appointments. Our [Construction cost estimating and planning]() service records the scope, assumptions and allowances behind a client’s construction budget. Record assumptions and unresolved design decisions. ## Sources 1. [What is a quantity surveyor?](). RICS. [Browse the Library]()