What Should a Builder’s Quotation Include?

A building quotation should help you understand exactly what is being priced, what is not included and how the work will be managed. The lowest total is not automatically the best value: two builders can appear to price the same extension while allowing for very different materials, finishes, services and site arrangements.

This checklist is designed for homeowners comparing quotations for an extension, refurbishment or structural alteration in Cambridge and Cambridgeshire. It is practical general information, not legal advice.

Quotation or estimate: what is the difference?

A quotation is normally an offer to carry out defined work for an agreed price, subject to its stated terms and any later variations. An estimate is an informed approximation and can change as the job becomes clearer. Citizens Advice recommends getting written quotations and checking the detail before agreeing to building work.

The distinction only helps when the scope is clear. A fixed number attached to a vague description can still leave important items unresolved.

Start with the same project information

For a meaningful comparison, every builder should price the same current information. That may include planning drawings, Building Regulations drawings, structural calculations, a specification, window and door schedules and any known drainage or ground information.

Check the drawing numbers and revision dates named in each quotation. If one builder has priced an earlier drawing set, the totals are not directly comparable.

What a detailed builder’s quotation should cover

1. The parties, property and quotation validity

The quotation should identify the contractor, customer, project and property, and state how long the price remains open for acceptance. It should also make clear whether VAT is included.

2. A stage-by-stage scope of works

Look for a logical breakdown rather than one line saying “build extension”. Depending on the project, headings might include site setup, demolition, excavation, foundations, drainage, floors, brickwork and blockwork, structural steel, roof construction, windows and doors, insulation, electrical work, plumbing and heating, plastering, joinery, tiling, decoration and external work.

A staged scope makes it easier to see whether the quotation covers the complete job and to compare it with another builder’s proposal.

3. Materials and performance requirements

Important materials should be described with enough detail to understand the allowance: for example, the wall construction, insulation, roof covering, window material, internal doors and finish level. Where the final product has not been selected, the quotation should explain the allowance or selection basis.

4. Allowances, provisional sums and unknowns

Some items cannot be fixed until more information is available. Ground conditions, utility diversions or a product that the homeowner has not selected may need an allowance. These items should be visible, explained and separated from fixed elements instead of being hidden inside the total.

Ask what happens if the actual cost is higher or lower than the allowance and how evidence will be provided.

5. Clear exclusions

Exclusions are as important as inclusions. Common examples can include planning and professional fees, structural engineer fees, utility-company charges, kitchens, sanitaryware, floor finishes, landscaping or decorating. The correct list depends on the project; the key is that it is explicit.

Also check which products are to be supplied by the customer and whether the builder’s price includes receiving, storing and fitting them.

6. Site setup and protection

A thorough quotation should say who is allowing for scaffolding, skips and waste removal, temporary supports, welfare facilities, dust protection, security and making good. For work to an occupied home, clarify how access and separation from the living area will be managed.

7. Programme and dependencies

Ask for the intended start window, the planned construction period and any important dependencies. Approvals, structural details, product lead times, access and customer selections can all affect a programme. A date should not be presented as guaranteed if key information is still outstanding.

8. A milestone payment schedule

Payments should relate to clearly described stages or completed work. Check the deposit, interim stages, final payment and any retention or defects arrangements. A schedule gives both sides a shared record of when payment becomes due.

The appropriate arrangement depends on the contract and project. The JCT Home Owner building contract, for example, provides for an agreed lump sum with either one completion payment or agreed interim payments.

9. A written variation process

Changes are common, but they should not be informal. The documents should explain how a change is described, priced, approved and added to the programme before the extra work proceeds where practicable. This protects the customer and contractor from different recollections later.

10. Responsibilities and approvals

Clarify who is responsible for planning conditions, Building Control liaison, structural design, Party Wall matters, utility applications and specialist design. The builder may coordinate some items without being the person legally appointed to design or approve them.

For the approval routes and documents to resolve before construction, see our Planning Permission Guide and Process and Permitted Development Guide and Process.

11. Insurance, warranties and certificates

Before accepting a quotation, ask for the contractor’s relevant insurance details. The contract or supporting documents should also explain applicable product guarantees, workmanship obligations and the certificates expected at completion, such as electrical or heating documentation where relevant.

12. Contract terms

The quotation describes the price and scope; a written building contract deals with the working relationship in more detail. It can cover responsibilities, access, payment, changes, delays, insurance, completion, defects and dispute procedures. Use a form suitable for the project and obtain independent professional or legal advice if you are unsure.

How to compare quotations fairly

• Put the totals side by side only after checking the same drawing revisions have been priced.
• Make a list of every allowance and exclusion.
• Check whether VAT, scaffolding, waste, finishes and making good are included.
• Compare payment stages and contract terms, not just the first payment.
• Ask each builder to explain any unusually low or high section.
• Review relevant completed work and genuine customer feedback.

A detailed quotation may take longer to assess, but it gives you much better information for deciding which proposal fits the project.

Questions to ask before accepting

• Which drawings and specification revisions did you price?
• What information or selections are still outstanding?
• Which figures are fixed and which are allowances?
• What is excluded?
• How are variations approved?
• What payment stages are proposed?
• What would prevent the planned start or completion dates?
• Which certificates and handover information will be supplied?

Getting a quotation from Prestige

A clear project brief helps us prepare a useful, itemised quotation. Where a visit would help confirm access, existing conditions or scope, we’ll arrange one.

What we need to quote

• Property address and brief
• Current drawings
• Planning and structural information
• Preferred start window and budget range

See examples of how different trades are coordinated in the Clay Street extension and refurbishment and our wider Cambridge building project portfolio. You can also read about our house extension service and property refurbishment work.

Request a quote when you’re ready to discuss the work.

More on planning, costs and contracts in our building guides.

Last reviewed: 30 August 2026. Planning, building-control, contract and consumer circumstances vary; obtain appropriate professional advice for your project.