Before a builder starts, get four things in writing: what the job is, what it costs, when it starts and finishes, and when you pay. Then check who will sign the work off under building regulations, and whether you need planning permission or a party wall notice. This guide takes you through each step, from the first quote to the final payment.
It applies whether you are planning an extension in Abingdon, a loft conversion in Bicester or a large repair in Witney. The same steps work across Berkshire, Buckinghamshire and Surrey too.
Start with the job, not the builder
Write down what you want done before you ask anyone for a price. It does not need to be long. A page is enough.
Cover these points:
- What: the work itself, such as a single-storey rear extension or knocking through two rooms.
- Where: which rooms or walls, and any access issues, such as a narrow side path or no parking.
- Finish: how far the builder goes. Up to plastered walls, or fully decorated with flooring down.
- Materials: who supplies what. If you are buying the kitchen or tiles yourself, say so.
- Drawings: any plans or structural calculations you already have.
Send the same scope to every builder you ask. That way each quote covers the same work, and you can compare them line by line. If one quote is much lower, the scope is the first place to look. Something may have been left out.
If you are planning an extension, our guide to building an extension covers the stages in more detail.
Ask for a written quote and a contract
A spoken price is easy to forget and hard to rely on. Ask for a written quote, and make sure it turns into a written agreement before work starts.
What the quote should say
- The scope, matching what you sent.
- Whether the price is fixed, or an estimate that may change.
- What is not included, such as skip hire, decorating or electrical work.
- Whether VAT is included.
- How long the price stands.
What the contract should add
- A start date and a finish date, or a clear length of time on site.
- The payment stages, and what must be done before each one.
- How changes are priced. Ask for any extra work to be agreed in writing, with its price, before it is done.
- Who clears waste and leaves the site tidy.
- Who arranges building control, and who pays for it.
- What happens if either side wants to end the agreement.
Ask too to see the builder's public liability insurance, and note its expiry date. A good builder will expect these questions.
Deposits and staged payments
Keep the money you pay up front small. Tie each later payment to a stage that is finished and that you can see.
A typical pattern links payments to points such as foundations done, walls up to roof level, roof on and watertight, and final completion. Agree the stages in the contract, not on the day.
- Pay by bank transfer, so there is a record.
- Ask for a receipt or invoice for every payment.
- Keep a simple list of what you have paid and when.
- If materials need buying early, such as windows made to measure, ask for that cost to be shown on its own.
Your right to cancel
If you agree a contract at home, away from the builder's business premises, you may have the right to cancel within 14 days. This comes from the Consumer Contracts Regulations 2013. There are exceptions, and the rules change if you ask for work to start inside the cancellation period. The government's guidance on the regulations explains how they work. It is general guidance, not advice on your own contract.
Building regulations: who signs the work off
Building regulations set minimum standards for safety, structure and energy use. Many building jobs need approval. GOV.UK keeps a list of the work that needs building regulations approval. Extensions, loft conversions and structural changes are common examples. So are some smaller jobs, such as replacing windows, fitting a boiler or changing a fuse box.
There are two main routes.
A competent person scheme
Some trades can sign off their own work because they belong to a competent person scheme. Electricians, heating engineers and window fitters often use one. When the work is done, you should get a certificate. GOV.UK says it should arrive within 8 weeks of the work being finished. If it does not, ask the installer. You can see the current authorised schemes on GOV.UK, and the Planning Portal explains self-certification as well.
The building control route
Larger building work, such as an extension, usually goes through building control. That can be your council's building control team or a registered building control approver. An inspector visits at key stages and issues a completion certificate at the end.
Ask every builder who will apply for building control and who pays the fee. Make it part of the contract. The legal duty to follow the rules applies to you as the owner as well as to the builder, so keep every certificate. You will need them when you sell.
For loft work, the Planning Portal has a page on when a loft conversion needs building regulations approval.
Planning permission and party walls
Planning permission and building regulations are separate. A job can need one, both or neither. Planning is about how the work looks and its effect on neighbours and the area. Building regulations are about how it is built.
The Planning Portal explains which common projects need permission, and where permitted development rules may apply. If your home is listed or in a conservation area, which is common in parts of Oxford, Thame and Henley-on-Thames, check with your council before you plan anything.
Party wall notices
If the work affects a wall you share with a neighbour, or involves digging near their foundations, the Party Wall etc Act 1996 may apply. The government's explanatory booklet sets out when you must give notice and how much notice is needed.
The owner serves the notice, not the builder. A builder may remind you, but the duty is yours. Leave time for it before the start date.
Checks to make yourself
Before you sign, spend a few minutes on official records. These are free to search.
- Companies House: if the builder trades as a limited company, look it up on Companies House. Check the name matches the quote, the company is active and the address makes sense.
- TrustMark: TrustMark is the government-endorsed quality scheme. You can search it for a business by name.
- Gas work: anyone working on gas must be on the Gas Safe Register. Search it yourself, and ask to see the engineer's ID card. Our post on how to check a Gas Safe engineer walks through it.
- Electrical work: look the electrician up on NICEIC or NAPIT. Our guide to Part P and electrical work explains why it matters.
To be plain: TradesAround does not look up these records for you, so please do it yourself before you agree anything.
Warning signs to watch for
Most builders are glad to put things in writing. Be wary if you see any of these:
- Pressure to agree today, or a price that only stands if you sign now.
- A request for a large payment before any work starts.
- Cash only, with no invoice or receipt.
- No written quote, or a quote with no detail.
- No clear answer on who handles building control.
- No start date, or dates that keep moving before the job has begun.
- Someone who knocks on the door to say they have spotted a problem with your roof or wall.
If something feels wrong, take a day to think. A sound quote will still be there tomorrow.
When work starts and when it ends
Once the job is under way, a few habits help.
- Take dated photos of progress, especially of work that will be covered up, such as foundations, drains and insulation.
- Agree every change in writing, with its price, before it is done.
- Keep a folder of the contract, invoices, receipts and certificates.
Near the end, walk round with the builder and write a snag list of anything unfinished or not right. Agree when each item will be fixed. Hold back the final payment until the snags are done and you have the building control completion certificate, or the competent person scheme certificate, in hand.
Finding builders near you
You can browse builders in Oxfordshire, or search by your town on our find a trade page. Each business has a Trust Score. It is an automated assessment of three things only: the business's Google reviews, its Companies House record and its TrustMark registration. Trust Scores aren't for sale. Pro members are listed first, with a Pro badge. You can read more about how TradesAround works.
Use the Trust Score as a starting point, not a guarantee. The scope, the written contract and your own checks are what protect you.
