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How do you compare extension quotations?

Updated 19 September 2026 · Project preparation

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Compare the same work packages, quantities and finishes before comparing totals. Separate exclusions and provisional allowances. A lower price may describe a smaller project, so clarify the specification before treating the difference as a saving.

How do bidders receive the same project brief?

Send every bidder the same drawings and requirements. Identify the drawing version and list decisions that remain open. Divide the work into preparation, groundworks, foundations, structure, external envelope, services and finishes.

A shell-only quotation answers a different question from an offer that includes decorating and floor finishes. Request a recognisable description for each package. Identify any work you intend to carry out yourself, so responsibility is not silently assumed by several parties or omitted by everyone involved in the project.

Which assumptions sit behind each figure?

A provisional allowance, called a stelpost, covers a choice or quantity that has not been completely resolved. Read its description as carefully as its amount. Ask which product, installation work and quantity have been assumed. Translate words such as premium, standard and ready to use into specific deliverables.

Waste removal, protection and temporary facilities also influence scope. Put a question beside every unclear item. Filling missing prices with an online average produces an apparently complete comparison without establishing what anyone has actually offered.

How do you compare responsibility and coordination?

Establish who prepares drawings, arranges structural assessment and handles any application. Then consider who coordinates the boundaries between packages. An electrician and kitchen supplier may each offer a clear quotation while their combined services layout remains unresolved.

Discuss how changes are recorded and how every affected party receives the same information. Ask what documents will be handed over at completion. The answers show which coordination tasks are included, who supplies missing information and how unresolved interfaces will be settled before they affect work on site.

Which follow-up questions clarify the differences?

Use work packages as rows and quotations as columns. Mark each item included, excluded, provisional or unknown. A blank cell should become a question for the bidder. Request clarification in writing and retain it with the relevant offer.

Revisit the totals after those differences have been explained. You can then see whether a price difference comes from materials, scope, preparation or execution. The eventual agreement should describe the same version of the project as the comparison on which you based your decision.

Frequently asked questions

Is the lowest quotation necessarily best value?

Only a comparison of equivalent scopes can show that. A lower amount may cover less finishing, different quantities or excluded preparation. Clarify those differences before interpreting the total as a saving.

How should I handle an unclear allowance?

Ask which selection, quantity and installation work it covers, and how the final cost will be reconciled. Keep the item marked unresolved until those assumptions are described clearly enough to compare.

Do quotations need an identical layout?

No, but their contents should be translatable into the same work packages. Request clarification where preparation, finishes or an interface is unclear. Attractive presentation alone does not make two offers comparable.

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