The best way to choose a local builder is to judge the paperwork and the people, not just the price. Look for a detailed written scope, clear inclusions and exclusions, payments tied to stages of work, someone who coordinates the trades, and recent projects like yours that you can check for yourself. This guide shows you how to test each of those, whether you are in Warrington, St Helens, Wigan, Worsley or anywhere nearby, and finishes with a checklist you can take to every quote meeting.
TL;DR
- Builders in the UK are not licensed, so the checking is down to you: ask for credentials, references and recent, similar work.
- Get at least three itemised, written quotes and compare like for like. A price far below the others usually means something has been left out.
- Insist on a written contract with start and finish dates, stage payments and a way of handling changes. FMB guidance says to avoid paying more than 25% upfront.
- A builder who coordinates trades and shows planning, Building Control and structural calculation fees as separate lines saves you chasing six different people.
- Ask for the completion certificate before you make the final payment. You will need it when you sell or remortgage.
Table of Contents
- Why choosing a builder is harder than it looks
- Start with the written scope
- Compare three quotes properly
- Payments should follow the work
- Coordination: why one point of contact matters
- Reviews and references that mean something
- Relevant experience, not just years in business
- Perspective: what we have learned in 35 years
- A practical checklist for choosing your builder
- Common mistakes to avoid
- How we work at Complete Property Solutions
- FAQ
- Sources
Why choosing a builder is harder than it looks
Most homeowners only hire a builder once or twice in their lives. You are handing over a large sum, letting people into your home for weeks or months, and relying on someone else’s judgement about walls, steel and drains that you will never inspect again once they are plastered over.
There is also no licence to check. As the Federation of Master Builders explains, building trades in the UK are unlicensed, so anyone can call themselves a builder. That is why trade association membership, verified references and a proper contract carry so much weight. None of them is a guarantee on its own, but together they give you a clear picture.
The good news is that the signs of a well-run firm are visible long before you sign anything. They show up in how a builder writes a quote, how quickly they reply, what they say about Building Regulations and how willing they are to let you speak to past customers.
Start with the written scope
The scope of work is the single most useful document you will get. It is a description of exactly what the builder will do, with what materials, to what standard. A one-line quote such as “single-storey extension, £X” tells you almost nothing and leaves every disagreement to be settled later.
A good scope should describe:
- the size and layout of the work, tied to the drawings
- foundations, walls, roof, insulation, windows and doors, with the specification of each
- electrics, plumbing, heating and plastering, and who does them
- finishes: flooring, tiling, decorating, kitchen fitting, or whether these are left to you
- site set-up, skip hire, waste removal and making good
- how long the work should take
The FMB’s quote guidance makes the point that a quote should always be written, and that an estimate is only an educated guess at cost. A quote for a fixed price is a firm commitment. An estimate is not. Ask which one you are being given, and get it in writing.
Inclusions and exclusions
Every quote has exclusions. The question is whether they are written down. Typical items that get left out of cheaper quotes include waste removal, specialist trades, decorating, VAT, scaffolding and the fixtures you assumed were included, such as radiators or the bifold doors.
Ask the builder to list what is not included, and ask what happens if the ground conditions or hidden problems change the work. Renovation work in particular can throw up surprises behind walls and under floors, so a sensible builder explains how those will be priced before they appear, not after.
Provisional sums
If a quote contains a provisional sum, such as an allowance for a kitchen or for extra foundation depth, ask what it covers and who decides when it is spent. A few are normal. A quote full of them is really an estimate wearing a quote’s clothes.
Compare three quotes properly
Get at least three written quotes, and give each builder the same drawings and the same brief. The FMB recommends at least three itemised quotes, and warns that a price far below the others may point to missing scope or poor planning, and that the cheapest builder can be a costly mistake.
A simple way to compare is to put the quotes side by side in a table like this:
| What to compare | Builder A | Builder B | Builder C |
|---|---|---|---|
| Fixed price or estimate | |||
| VAT included | |||
| Waste removal and skips | |||
| Planning and Building Control fees shown | |||
| Structural calculations and engineer | |||
| Windows, doors and roof specified | |||
| Payment stages | |||
| Start date and duration |
When one column has far more blanks than the others, you have found the quote that is not yet complete, whatever the total says. We have set out a longer walkthrough in our builders’ quote checklist for North West homeowners.
Payments should follow the work
A contract should set out when you pay and why. Citizens Advice says to have a written contract that covers timings, materials, waste removal, payment stages and how delays are handled, and to avoid paying cash.
A staged schedule typically ties each payment to a milestone you can see, for example foundations complete, structure watertight, first fix finished, and a final payment on completion. The FMB’s advice is to avoid paying more than 25% upfront. If a builder asks for a very large deposit before any work starts, treat it as a reason to slow down and ask why.
Keep a record of every payment, pay by traceable methods and agree in advance how a variation will be priced and signed off. A short written note, signed by both of you, avoids most arguments about extras.
Coordination: why one point of contact matters
A house extension is not one job, it is a dozen. Groundworkers, bricklayers, carpenters, roofers, electricians, plumbers, plasterers and glaziers all have to arrive in the right order. If you hire them separately, you become the project manager, and a delay by one trade quickly becomes a delay for everyone.
A builder who coordinates the trades takes that sequencing off your shoulders. It is worth asking directly:
- Who will be on site day to day, and who do I call?
- Which trades are your own team and which are subcontracted?
- How do you handle it when a delivery is late or a trade does not turn up?
- How will you keep me updated: a weekly call, a message, a site meeting?
Planning, Building Control and structural calculations
The best builders also help you through the paperwork, and show the cost of it clearly. Planning permission and Building Regulations are two separate things. Some smaller extensions fall under permitted development and need no planning application, but they usually still need Building Regulations approval. If you are unsure, our guide to permitted development for house extensions is a good place to start, and our comparison of permitted development versus planning permission covers how to decide.
On the Building Regulations side, GOV.UK explains that you apply through a building control body, which can be your local authority or a private approved inspector. A full plans application gives you more certainty before work begins, and you need the completion certificate afterwards when selling or remortgaging.
For the planning application itself, a householder application in England currently carries a fee of £548. Drawings, structural calculations and Building Control fees come on top, so ask your builder to list each one as its own line. Fees that are named and priced are fees you can compare. Fees buried in a lump sum are not.
If you are knocking through a wall, the work will usually need an engineer’s calculations for the steel beam (an RSJ) before it goes in. Ask who produces them, who pays, and whether the cost is already in the quote.
Reviews and references that mean something
A star rating is a start, not an answer. Read the reviews for detail: do they describe the work, the tidiness, the communication and what happened when something went wrong? A pattern across several years of reviews tells you more than one glowing paragraph.
The FMB advises asking for details of recent customers with similar projects and, with their permission, speaking to them about whether the final cost matched the quote and how problems were handled. Better still, ask to see a finished job in person.
Sensible questions for a past customer:
- Did the final bill match the quote, and if not, why?
- Did the work finish roughly when promised?
- How was the site kept day to day?
- What went wrong, and how was it dealt with?
- Would you hire them again?
Relevant experience, not just years in business
A builder who mostly does loft conversions may not be the right choice for a wraparound extension, and a firm that has never fitted bifold doors may struggle with the structural openings they need. Ask for projects that match yours in type and scale, and ask what lessons they took from them.
Local knowledge counts too. A builder who works regularly in Warrington, St Helens, Wigan or Worsley will know the local planning authorities, the typical house types and the Building Control teams. That means fewer surprises with a 1930s semi in Great Sankey than a firm travelling from further afield might expect. Local also means easy to reach: you can visit their previous work and they can be back on site quickly if something needs attention.
Trade bodies help as a second check. Membership of an organisation such as the Guild of Master Craftsmen or the FMB shows a builder has put themselves forward for scrutiny, but verify membership directly and still ask for references. When you are planning home renovations, sorting out dates, access and where your belongings will go during the work is as important as the build itself, so ask each builder how they handle that.
Perspective: what we have learned in 35 years
We are a family-run company, and we have been building for more than 35 years. The conversations that go best are the ones that begin with the homeowner asking hard questions about scope and price, and we welcome that.
Our view is simple. A fixed-price quote only means something if it describes exactly what is included. That is why we put our quotations in writing as fixed prices, and why we run projects from the design stage to completion rather than handing you a list of trades to chase. Homeowners tell us the thing they value most is knowing who to call and getting a straight answer.
If a builder is reluctant to put things in writing, or pushes you to decide quickly, take that as information. A good builder expects you to compare, and is happy to be compared on the detail.
— Gareth
A practical checklist for choosing your builder
Take this to each quote meeting and tick things off as you go.
Before you meet
- [ ] Write a clear brief and, if possible, have drawings ready so every builder quotes for the same job
- [ ] Check what permissions you need: planning, Building Regulations or both
- [ ] Shortlist three local builders with relevant, recent projects
At the site visit
- [ ] Does the builder look at the house properly and ask about how you live?
- [ ] Do they explain Building Regulations and who deals with Building Control?
- [ ] Can they name who will be on site and who manages the project?
In the quote
- [ ] Written, itemised, with VAT stated
- [ ] Clear inclusions and exclusions
- [ ] Planning, Building Control and structural calculation fees listed separately
- [ ] Windows, doors, roof and materials specified
- [ ] Provisional sums explained
In the contract
- [ ] Start and finish dates
- [ ] Stage payments tied to milestones, with no big upfront deposit
- [ ] How variations are priced and agreed
- [ ] Waste removal and site tidiness
- [ ] Completion certificate handed over at the end
Checks on the builder
- [ ] Trade association membership verified directly
- [ ] Reviews read for detail and patterns
- [ ] At least two recent customers contacted, or a finished job visited
- [ ] Insurance cover confirmed in writing
Common mistakes to avoid
- Choosing on price alone. The lowest quote often leaves out items you will end up paying for later.
- Paying a large deposit. Pay in stages against progress.
- Starting without approval. Building without the right Building Regulations sign-off can cause problems when you sell.
- Agreeing changes verbally. Always note variations in writing, with the price and any effect on the schedule.
- Skipping the site visit. A builder who has not seen the house cannot price it accurately.
- Leaving the timeline vague. Ask for a realistic programme and what could change it, such as weather or ground conditions.
How we work at Complete Property Solutions
We are a family-run building company covering Warrington, St Helens, Wigan, Rainhill, Great Sankey, Penketh, Culcheth, Lowton, Haydock, Worsley and the surrounding areas. We are a member of the Guild of Master Craftsmen, an approved HUP! Building System partner, an approved UltraRoof installer and an authorised REHAU installer.
What we build includes house extensions, kitchen extensions, garage conversions, structural alterations, HUP extensions and garden rooms, replacement conservatory roofs and full renovations, along with replacement windows and bi-folding, aluminium and composite doors. Our quotations are fixed price, and we manage each job from design through to completion.
If you would like to talk through your project, get in touch and we will arrange a site visit, look at what you have in mind and talk you through the next steps. For a deeper look at the criteria above, our checklist for choosing extension builders goes into more detail.
FAQ
How do I know if a builder is good?
Look for a detailed written quote, a clear contract, verifiable trade association membership and recent customers who will talk to you. A good builder explains Building Regulations without being asked, and is happy for you to see finished work. How they communicate before you hire them is usually how they will communicate during the job.
How many quotes should I get?
At least three, all written and itemised, and all based on the same drawings and brief. The FMB recommends comparing scope as well as price. If one quote is much lower than the others, ask what has been left out before you get excited about the saving.
Can you haggle with a builder?
You can ask whether the price has any flexibility, but squeezing a fixed price often leads to corners being cut or extras appearing later. It is usually more productive to adjust the scope, such as the specification of finishes, than to push the labour cost down. A fair builder will show you where the money goes.
How much should I pay upfront?
As little as the contract needs. The FMB suggests avoiding more than 25% upfront, with later payments tied to stages of completed work. Avoid cash, and keep a record of every payment.
Do I need a completion certificate?
For work that needs Building Regulations approval, yes. GOV.UK explains the application process, and the certificate is what a buyer’s solicitor or a lender will ask to see later. Ask your builder at the start how and when it will be obtained.
Sources
- How to choose a trusted builder in the UK, Federation of Master Builders
- Five things you need to know about getting a quote for building work, FMB
- Before you get work done on your home, Citizens Advice
- Building regulations approval: how to apply, GOV.UK
- Planning permission cost UK 2026: fees, Costwise UK
- Master planning home renovations
