Quantity Surveyor Fee Calculator 2025/26

A quantity surveyor (QS) manages the financial and contractual aspects of a construction project. Pre-contract: feasibility cost advice, cost planning, bills of quantities, tender preparation and analysis, contract selection. Post-contract: valuing contractor applications for payment, agreeing variations, monitoring costs against budget, and settling the final account. A QS protects the client's financial interests throughout the project and is particularly valuable on larger or complex projects where cost control is critical.

For small residential projects (extensions under £100,000), a dedicated QS is often not cost-effective. The architect may provide basic cost advice and the contractor will price from drawings. For larger projects (new builds, major refurbishments over £200,000), a QS adds significant value by: obtaining competitive tenders, identifying savings opportunities, managing variations, and ensuring the final account is correct. On projects over £500,000, QS fees typically pay for themselves through savings and avoided disputes.

A bill of quantities (BoQ) is a document prepared by a QS that lists all the materials, parts and labour required to construct a building, with quantities measured from the architect's drawings. Contractors price each item, producing a like-for-like tender that enables accurate cost comparison. BoQs reduce the risk of disputes as both parties agree the scope and price of each item before construction starts. They are standard practice on larger commercial projects but less common on residential projects, where specification and drawings are typically used instead.