BUILDING PROJECT INFORMATION
How to Compare Builder Quotes
Two builders can look at the same home and come back with very different prices. The important question is whether they’ve priced the same work. This guide shows you how to spot missing items, understand allowances and compare quotations before making a decision.
Put the same project behind every price
A quotation is only useful if you know exactly what it covers. Imagine asking three builders to price a new kitchen-diner: one includes the structural opening and new electrics, another assumes you’re arranging the kitchen yourself, and a third leaves flooring and decoration out. They may all be quoting in good faith, but you cannot fairly compare the totals yet.
Start by giving each contractor the same current drawings, room requirements and specification. Make a note of the versions they’ve priced. If you’re still working from sketches, tell them what’s undecided. It is better to be clear about uncertainty now than to discover after appointment that you and the builder pictured different finished rooms.
This guide helps you compare quotes for extensions, garage conversions, loft conversions and renovations. It does not certify prices or choose a contractor for you. It gives you a straightforward way to ask better questions and recognise when a proposal needs more detail.
01
Same drawings
Confirm each builder has priced the same revision and room requirements.
02
Same finish
Check what the finished rooms will actually include.
03
Visible exclusions
Record everything left out, provisional or still unclear.
04
Clear next decision
Ask for written clarifications before choosing an offer.
Establish what kind of price you have
If one builder gives you a detailed written quotation and another gives you a ballpark estimate after a brief call, they aren’t offering the same level of certainty. Ask each contractor what information they’ve relied on and what needs checking before the figure can be confirmed.
Citizens Advice distinguishes an estimate of likely cost from a quotation for agreed work. Check the date, VAT treatment, validity period, assumptions and any conditions. Where a visit, drawing or investigation is outstanding, have that recorded rather than treating a provisional price as final.
UNDERSTANDING THE FIGURE
Quotation, estimate or early budget?
Quotation
Ask what agreed work and specification the figure covers, and which conditions apply.
Estimate
Understand which details are still being assessed and what could change the likely cost.
Provisional allowance
Find out what has been allowed for, what is not yet selected and how the final cost will be settled.
The document’s wording and terms matter more than the label printed at the top.
Create a useful scope comparison
A tidy comparison sheet can quickly reveal why one quote appears cheaper. Put the work into sensible categories, then mark each contractor’s response as included, excluded, provisional or unclear. Do not assume that phrases such as “fully finished” or “all necessary works” answer the detail.
For a house extension, you might need groundworks, structural openings, glazing, roof connections and changes to existing rooms. A garage conversion could involve the old garage opening, insulation, services and the standard of the new room. Adapt the checklist below to the actual project rather than treating it as a fixed specification.
Where an item is unclear, ask the builder to clarify it in writing. That is not being difficult. It is how you find out whether you are comparing equivalent proposals, and it gives both parties a better basis for the work.
The six areas worth checking
Use the same categories for every quotation. A blank or vague answer should stay marked “unclear” until the contractor confirms the scope.
| Compare | Check in each quote | Record |
|---|---|---|
| Scope and drawings | What plan revision and rooms are included? | Same documents or explain differences |
| Structural and building work | Groundworks, walls, roof, openings and making good | Included / excluded / provisional / unclear |
| Services | Heating, plumbing, electrics, ventilation and testing | Who supplies and connects everything? |
| Products and finishes | Doors, flooring, kitchen, bathroom, decoration | Which items and fitting costs are included? |
| Design and approvals | Surveys, drawings, structural design, applications | Who is responsible and who pays? |
| Practical arrangements | Access, protection, waste, scaffolding, VAT | Any additional cost or assumption? |
AFTER THE FIRST COMPARISON
Know what is missing before choosing on price
If you have already received a quotation, you can use this checklist to put your questions into order. If you are still planning the work, describe the room you want and what information you have so far. You do not need to pretend every detail is settled.
Compare specifications, not just headings
Two quotations might both say “new windows” or “supply and fit kitchen”, but those descriptions alone tell you very little about the products or work included. Check quantities, fitting, finishing and any named specification. Is the allowance for the kitchen unit supply only, or does it cover worktops, appliances, installation and service connections?
You do not need the most expensive finishes for a good result. You need a specification that matches how you want to use the room and a clear account of what is being supplied. If you are choosing flooring or kitchen fittings later, ask what allowance has been included and what happens if your eventual selection costs more.
The easiest way to compare builders fairly is to avoid imagining extras that have not been written into the offer. Ask for the detail that matters to your household and keep the confirmed answer with the quotation.
Read assumptions and exclusions first
Exclusions are often where apparent savings disappear. One contractor might include decorating and making good around an opening, while another leaves those tasks for a separate trade. Design fees, authority charges, bathroom fittings, external work and kitchen supply may also be outside the builder’s total.
An exclusion is not automatically a warning sign. It may be perfectly reasonable if you know who is responsible for the missing work and have included it in your own budget. The problem comes when you assume it is covered and have to arrange and pay for it later.
Read the assumptions just as closely. Access, ground conditions, the existing structure and service connections can all affect the proposed scope. A clear caveat is usually more useful than a reassuring but unexplained “everything included”. Ask what needs to be checked, and when.
If you’re still preparing plans, the project-brief guide can help you give each builder a consistent set of information.
Understand allowances and changes
A provisional sum is not the same as a final agreed cost. Ask what work or product it covers, why the amount is provisional and when it will be fixed. This matters when one quotation appears lower because it allows less for items that you still need.
It also helps to agree how changes will be handled. You may decide on different doors or discover that an existing area needs additional work. Before that becomes an instruction, ask for the revised scope, price and effect on the programme in writing.
You are not trying to eliminate every uncertainty from a building project. You are making sure you can see the uncertainty, understand who will assess it and make informed decisions before extra costs are authorised.
WHEN YOU WANT A CLEARER QUOTE
Make the next conversation more useful
A useful enquiry is not a lengthy technical specification. Tell us what you want to achieve, where the property is and whether you have sketches, drawings or earlier quotations. Those details help establish what should be discussed next rather than encouraging a misleading price based on guesswork.
Review payment and programme together
Once the scopes are comparable, look at when money is due. Ask what each payment stage represents, how progress will be confirmed and how deposits or advance purchases are handled. A price that looks attractive can create practical concerns if the payment terms are not properly understood.
The programme matters too. One contractor may assume design information, approvals and products are ready before work starts. Another may have allowed time for those decisions. Discuss disruption, access, deliveries and the rooms you need to keep using while the work is under way.
Do not accept a start-date promise as a substitute for a clear scope. Your chosen contractor should explain the important dependencies and how changes to the work or specification would be communicated.
Check who would carry out the contract
Even a well-written quotation needs to come from a business you are comfortable appointing. Check the legal or trading name, relevant contact information and the party who would actually be responsible for the work. If different names appear across the quotation and insurance documents, ask for an explanation.
References, insurance and claimed accreditations answer different questions from the price itself. Verify the evidence that matters to your decision. An attractive photograph or logo is not proof of what a particular contractor will do at your property.
You can use the Checking Contractor Documents guide alongside this comparison. It helps you keep the identity and evidence checks separate from the task of agreeing the construction scope.
Request a clarified final offer
When you know which questions remain, send each contractor a short organised list referring to the relevant drawing, item or assumption. Ask for written clarification or a revised offer that shows what has changed. If you have made a significant alteration to the brief, make sure anyone still being considered has the same information.
Before choosing, you should be able to explain what the quote includes, what it excludes, what remains provisional, what you will buy directly and what happens next. The lowest number is not necessarily the best value. The right comparison is the cost of the complete result you actually want.
The final construction agreement needs to match the offer you accept. Keep the confirmed quotation, drawings and clarifications together so an earlier version does not accidentally become the reference for the work.
Your Questions
If two builders have given you different prices, you may be unsure whether the cheaper quotation really leaves anything out. These are some of the questions homeowners commonly need to settle before making a decision.
You can use the answers below to prepare your own comparison, then ask each contractor to explain the details of your particular job in writing.
What should I compare before looking at the quotation total?
Check that every contractor has priced the same drawing revision, scope and specification. Then compare inclusions, exclusions, allowances, supply responsibilities and the intended completed condition. Note whether VAT and relevant fees are included. A lower figure may simply cover less work, so unresolved differences should be clarified in writing before deciding which offer represents the appropriate proposal.
How can I compare quotations with different provisional allowances?
Identify what each allowance covers, the assumption behind its amount and the process for agreeing the actual cost. Where possible, settle the relevant choice or information and request revised prices on the same basis. Avoid adding allowances together as though they were fixed commitments. The comparison should show both the starting figure and where meaningful uncertainty remains.
What should I do if one quotation is much cheaper?
Ask the contractor to explain the scope, assumptions and exclusions against your current project information. Check materials, service work, finishes and any tasks another business must supply. A difference is not by itself evidence of poor work or good value. Understand what produces the saving and record any clarification before relying on the price in an appointment decision.
Should programme and payment arrangements form part of my comparison?
Yes, consider them alongside the scope and price. Ask what assumptions support the proposed timing, which decisions you must make and how payment stages relate to the agreed work. Discuss changes, delays and communication procedures before appointment. The aim is a clear and practical agreement, rather than choosing a headline total while leaving the working arrangements unresolved.
Sources and Further Guidance
Citizens Advice provides useful guidance on written quotations, estimates and preparing for building work. Its information can help you understand the questions to ask, but your own quotation and contract still need to be checked against the work you are proposing.
Use official consumer guidance alongside the actual drawings and terms. When an important obligation or financial commitment is unclear, seek appropriate advice before agreeing to it.
Guidance checked 25 October 2026. General information does not determine the requirements for an individual property.
PROJECT CONNECTIONS
Put the Information Into Practice
The right service depends on the work you are actually considering. These two options are useful comparisons when the aim is to create more space, but the building scope, constraints and quotation questions can be quite different.
Double-storey extensions
If you are comparing quotations for additional rooms upstairs as well as down, review what a double-storey extension might involve. The upper floor, structural arrangements and work inside the existing house can change the scope.
Home conversions
Loft and garage conversions have different starting conditions from an extension. If your aim is an additional usable room, compare the likely work for each option before asking builders to price unlike-for-unlike designs.
PROJECT LOCATION
Compare Quotations for Your Area
Choose the area that matches your property, then use the enquiry form below to describe the work you have in mind. The map helps you select the location; it does not establish approval or pricing for your particular home.
GEOGRAPHICAL PROJECT CONTEXT
Building Services Across Merseyside
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YOUR PROJECT
Request a Building Quote
Tell us the property location, what you want the builder to do and how far your plans have progressed. If you already have drawings or a quotation, mention what needs clarifying. If you are still at the ideas stage, an initial enquiry is fine too.
Your enquiry
- The type of work and intended room use
- Your postcode or town
- Plans, approval steps or advice already obtained