How to compare builders' quotes without missing the gaps

Three builders return prices for the same development. One looks considerably cheaper. Before deciding whether it is better value, you need to establish whether everyone has priced the same work.

For a small residential developer, this can mean an evening moving between quotations, drawings, specifications and emails. AI can help prepare that comparison. Its most useful output is a clear list of differences and questions for you, your quantity surveyor and the builders to resolve.

Start with one agreed information pack

Collect the quotations and the exact documents issued for pricing: drawings, specifications, schedules, tender clarifications and subsequent revisions. Record the version and date of each. Ask which documents each builder used; do not assume their references match your latest folder.

Choose a manageable package first, such as windows, landscaping or kitchens. Comparing a defined package is easier to check than asking AI to assess an entire development immediately.

Create a short list of the scope items that matter. For windows, that might include supply, installation, glazing specification, ventilation details, access equipment, making good and lead times. Your project team should define this list.

Ask for a comparison you can trace

Give every requirement a row and every builder a column. Each cell should identify what the quotation says, where it says it and what needs clarification. Use explicit labels:

• Included: the quotation expressly covers the item.
• Excluded: the builder expressly leaves it out.
• Allowance: a stated sum is included, with its basis recorded.
• Unclear: the wording does not settle the question.
• Not found: the system could not locate a reference.

“Not found” must never silently become “included” or “excluded”. Keep the page reference or spreadsheet cell beside the extracted wording. This lets someone check a concern without rereading the whole pack.

Record the proposed programme, quotation validity, payment assumptions and qualifications alongside price. RICS' Tendering Strategies guidance includes programme, exclusions and alternative offers among the information recorded when tenders are opened. A headline total is only one part of the comparison.

An illustrative example: the cheaper window package

Illustrative example, not a client result. Builder A quotes £68,000 and Builder B quotes £75,000 for a window package, on the same stated tax basis. A excludes scaffolding and making good; B expressly includes both. Both reference the same glazing specification.

The apparent difference is £7,000. That is not yet a saving. The useful AI output highlights the exclusions and drafts two questions: what would A charge to include them, and does B's making-good allowance cover the required finish?

Keep the original prices unchanged. If your quantity surveyor adds an allowance for comparison, show it in a separate column with its source and status. An internal estimate is not a builder's agreed price. A subsequently confirmed extra cost should replace that estimate rather than being added again.

Turn the differences into clear questions

Prepare a separate clarification list for each builder. Each question should identify the relevant requirement, quote the ambiguous wording and request a specific answer. “Please confirm whether installation includes access equipment for both plots” is easier to resolve than “Please clarify your exclusions”.

A person should check the questions before sending them. Do not disclose another bidder's confidential prices or commercial approach. Save each response with its date and update the comparison, preserving the earlier version.

Your final review should consider delivery capacity, relevant experience and programme as well as the clarified price. AI can organise that evidence; the appointment decision stays with the developer and their advisers.

What a sensible first implementation looks like

Start with two or three completed quotations and a comparison someone has already reviewed. Check whether the proposed workflow extracts amounts correctly, preserves qualifications and catches known omissions. Include an awkward scan and an ambiguous answer in the trial.

Calculations should use checked spreadsheet formulas or another calculation process, with extracted figures reconciled to the source. Someone must verify tax treatment, units, quantities and totals. Upload only information you are authorised to use into an appropriately controlled workspace.

Indicative NSV scoping estimate: a prepared demonstration using a small, readable sample can fit into 15 minutes. Establishing a repeatable workflow for one package, agreed exports and a comparison template may take five to ten working days. Poor scans, multiple document formats and integrations can extend that scope.

Measure time to a reviewed comparison and the number of important differences correctly surfaced. Bring one representative package to an AI Workflow Planning discussion, and the first task is to agree what a useful, checkable comparison should contain.