Bill of quantities: what it should include

A lump sum for 'renovating an apartment' says nothing about what is actually included. A BoQ breaks the project into specific items — for example, '18 sq. m bathroom wall tiling', 'rewiring, 6 rooms' — and states a quantity and price for each. That way both sides know exactly what is being paid for and what is expected to be delivered.

This is the basis for a fair comparison of quotes from different contractors, because it shows where a difference comes from quantity, where from material, and where from labour.

A good BoQ is usually organised by room or by type of activity (demolition, masonry, installations, finishing works) and contains the following columns for each item.

• Item number and a short description.
• Unit of measurement (sq. m, linear m, unit, set).
• Quantity.
• Unit price for labour and for material (separated where possible).
• Total value of the item.
• A note on material specification, where applicable.

A grand total is added at the end, along with a separate contingency as a percentage, if the contractor and client have agreed on such a reserve.

Renovations rarely go exactly to the original plan — the client changes a tile choice, or breaking into a wall reveals a problem that was not visible before. This is exactly where a BoQ helps: every change from the original sheet can be described as a new or revised item with a clear quantity and price, rather than being added as a vague lump sum at the end.

• Every change is recorded in writing, referencing the relevant BoQ item number.
• The new price is agreed before the work is done, not after the fact.
• Copies of the original and updated versions are both kept.

In this hypothetical example, the change is traceable — it is clear exactly where the difference comes from, rather than appearing as an unexplained addition on the final invoice.

A BoQ is not a standardised legal document and there is no fixed statutory form for private renovation work — the structure described here is a practical recommendation, not a template to replace a contract. On larger projects, the works contract itself and the handover protocols remain the main legal instruments, with the BoQ serving as an attachment to them.

Before accepting a BoQ as the basis for a contract, it is worth asking a few direct questions that show whether the contractor has calculated the real volume of work, rather than putting in an approximate lump figure.

• Do the quantities reflect an actual on-site survey, or are they based on design area without verification?
• Are unit prices fixed for the whole duration of the project, or can they change if material costs rise?
• What happens to an item if the real quantity turns out different from the one stated — for example, an uneven floor requiring more screed?

Ask the contractor for a BoQ at the quote stage, not after signing a contract. If the contractor is not used to producing one, you can structure it together along the lines above — this reduces the risk of disputes later, especially alongside the conversation on choosing a building contractor and advance payment terms.