If you've ever been involved in a construction project, you've probably heard the term 'Bill of Quantities' — or BoQ. But what exactly is it, and why does it matter? This article explains everything you need to know in plain English.
What Is a Bill of Quantities?
A Bill of Quantities is a detailed document that lists every item of work required to complete a construction project. Each item is measured and described in accordance with a standard method of measurement — in the UK, this is typically the New Rules of Measurement (NRM) published by the RICS. The BoQ is sent to contractors as part of the tender package, allowing them to price the job, which means every contractor is pricing the same scope of work. Without a BoQ, each contractor interprets the drawings and specification differently — making bids impossible to compare fairly. With a BoQ, you can see exactly where the price differences lie and negotiate from a position of knowledge. A well-prepared BoQ typically achieves 5–15% savings against lump sum tenders, because contractors can't hide risk allowances in ambiguous scope. The BoQ also provides a schedule of rates for valuing changes during construction, which prevents disputes and ensures fair pricing.
What Does a BoQ Include?
A typical BoQ is divided into sections corresponding to the elements of the building: preliminaries (site setup, management, and temporary works), substructure (foundations and below-ground works), superstructure (frame, floors, roof, and external walls), internal finishes (walls, floors, ceilings), fittings and furnishings, services (mechanical and electrical), and external works (drainage, landscaping, car parking). Each section lists individual work items with their description, unit of measurement, quantity, and rate — with the contractor completing the rate and extension columns.
Why Is a BoQ Better Than a Lump Sum Tender?
Without a BoQ, contractors price the works as a lump sum based on their own interpretation of the drawings and specification. This creates several problems: bids are difficult to compare because each contractor may have priced different things; the scope of work is ambiguous, leading to disputes and variations during construction; and there's no mechanism for fairly valuing changes to the works. A BoQ eliminates these issues by defining the scope precisely and providing a schedule of rates for valuing variations.
How Long Does it Take to Produce a BoQ?
The time required depends on the size and complexity of the project. For a straightforward residential project, a BoQ can typically be produced in 3–5 working days. For a large commercial development, it may take 2–4 weeks. At Page Building Consultants, we use advanced estimating software that significantly accelerates the measurement process — we can typically produce BoQs 50% faster than traditional manual methods, without compromising accuracy.
When Should You Commission a BoQ?
A BoQ should be commissioned once the design is sufficiently developed — typically at RIBA Stage 4 (Technical Design). At this point, the drawings and specification should be complete enough to measure the works accurately. Commissioning a BoQ too early, when the design is still evolving, will result in significant re-measurement work and additional cost. Too late, and you risk delaying the tender programme.
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A well-prepared Bill of Quantities is one of the best investments you can make in your construction project. It reduces risk, improves tender quality, and provides a solid foundation for cost management throughout the build. Contact us to discuss your project's BoQ requirements — we provide fast, accurate, and competitively priced services.
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