How to read a BOQ before you tender

A good BOQ is a map of the build — not a wishlist. Before you float it to contractors, walk these checks.

Start with the preliminaries

Preliminaries cover site establishment, insurance, temporary works and mobilisation. If this section is thin, every tenderer will invent their own allowance — and your “lowest” quote will not be comparable.

Match quantities to drawings

Pick three high-cost items (foundations, walling, roofing). Reconcile the measured quantities against the latest architectural and structural drawings. Mismatches here are the usual source of mid-contract claims.

Read the exclusions aloud

Exclusions are where budgets blow up. Confirm whether VAT, external works, septic, power connection and kitchen joinery are in or out. Write the answer into the tender invitation so every bidder prices the same scope.

Ask for a rate build-up on key trades

For concrete, reinforcement and roof covering, ask tenderers to show how they arrived at the rate. You will quickly see who is guessing and who has current supplier quotes.

Close with a site visit

Invite shortlisted contractors to walk the plot together. Note ground conditions, access for trucks, and neighbouring boundary constraints. Capture those notes as an addendum before award.

Done consistently, this discipline keeps tender sums honest and protects both client and builder when work starts on site.