Buying a new build home: the legal steps

How a new build purchase differs

Buying a new home from a developer follows the same basic route as any purchase, with some important differences. You often commit before the home is finished, the developer sets tight deadlines, and the contract is the developer's standard document rather than one negotiated line by line.

Your conveyancer checks that what you were promised matches the contract, that the home will have an acceptable warranty, and that roads, drains and shared areas will be looked after. Your part is to move quickly, keep your mortgage on track and understand what happens if the build runs late.

Step 1: Reserve your plot

When you choose a plot, you sign a reservation agreement and pay a reservation fee, for example £1,000, although amounts vary. This takes the plot off the market at an agreed price for a set period. The agreement says how long the price is held, what happens to the fee if you pull out, and when you must exchange contracts, the point where the purchase becomes legally binding.

Developers commonly expect exchange within a few weeks. If your developer has signed up to the New Homes Quality Code, a code of practice for home builders, your reservation comes with a cooling-off period of at least 14 days, in which you can cancel and get the full reservation fee back. The exchange date must also be at least six weeks after reservation unless you ask for an earlier one, and the developer must make clear that you are free to choose your own conveyancer. These protections were in the first version of the Code, and the updated Code applies to homes reserved from 2 March 2026.

Instruct your conveyancer the day you reserve, and send them the reservation agreement, price list, plot plan and details of any incentives.

Step 2: The developer's contract pack

The developer's solicitor then sends a contract pack. It usually includes the draft contract and transfer (the deed that passes ownership to you), plans of your plot and the estate, the title to the development, the planning permission, the specification (the list of finishes and fittings) and details of the warranty and any management company.

Your conveyancer checks that the plot boundaries match what you were shown, that the planning permission covers your home and that you will have legal rights to use the roads, paths and services. They also check whether the roads and sewers will be adopted, meaning taken over and maintained by the council and the water company, usually under section 38 (roads) and section 104 (sewers) agreements. If they will not be adopted, you need to know who pays to maintain them.

Expect questions to go back and forth with the developer's solicitor. Developers often reply quickly but are usually reluctant to change their standard terms.

Warranties and building quality

Most lenders will only lend on a new home with an acceptable new home warranty, a policy that covers certain defects. NHBC's Buildmark is a common example: broadly, the builder must put right defects reported in the first two years, and insurance then covers certain defects, mainly structural, in years three to ten. It also protects your deposit if the builder becomes insolvent between exchange and completion (the day you pay the balance and get the keys).

Other providers, such as LABC Warranty, offer similar policies, and some lenders accept a certificate from an architect or other professional who supervised the build. Your conveyancer checks that the warranty is in place or will be issued at completion, and that your lender accepts it.

Keep the warranty documents safe. You will need them if a defect appears, and a future buyer's conveyancer will ask for them.

Step 3: Exchange, completion on notice and the longstop date

Many new homes are not finished when you exchange. Instead of a fixed completion date, the contract usually says completion will take place a set period after the developer gives notice that the home is ready. This is called completion on notice. The period is commonly around two weeks, and the New Homes Quality Code expects at least 14 calendar days unless you agree otherwise, so be ready to complete at fairly short notice.

The contract should also contain a longstop date: the latest date by which the developer must finish the home. If it is not ready by then, you can usually cancel and get your deposit back. Your conveyancer checks the longstop date and explains your options if the build runs late.

On exchange you pay a deposit, often 10% of the price, although some developers accept less. Do not give notice on a rented home or book removals until the developer has served notice to complete.

Mortgage offers and incentives

Mortgage offers do not last forever. Many are valid for around six months, and some lenders allow longer for new builds. If the build is delayed beyond the expiry date, you may need an extension or a new application, and a fresh valuation could come in lower. Ask your broker about the validity period before you exchange, and compare it with the developer's expected completion date and the longstop date.

Developers often offer incentives, such as paying towards your deposit or legal fees, or including flooring and appliances. The developer usually has to declare incentives to your lender on a standard disclosure form, and the lender may lend less if they affect the true price. Tell your broker and conveyancer about every incentive at the start.

Step 4: Snagging and the pre-completion inspection

Snagging means finding and listing defects, from scuffed paintwork and sticking doors to missing sealant or badly fitted tiles. If your developer has signed up to the New Homes Quality Code, it must give you the chance to inspect the home before completion, yourself or through a qualified inspector, usually after it has served notice to complete.

Take your time, use a checklist, photograph problems and send your list to the developer in writing. Many snags are fixed after you move in, during the period when the builder is responsible for defects, so keep a record of what you reported and when. Your conveyancer cannot inspect the home, but can tell you what the contract says about putting defects right.

Estate management charges

Many new estates have open spaces, play areas, private roads or drainage features that the council will not take over. These are often owned by a management company, and each homeowner pays a yearly estate management charge towards their upkeep, even if the home itself is freehold.

Your conveyancer checks what the charge covers, how it is calculated, whether it can rise and what happens if it is not paid, because some deeds give the management company strong powers over unpaid charges. Changes affecting estate management charges are being brought in by the Leasehold and Freehold Reform Act 2024; your conveyancer will tell you what applies on the date of your transaction.

A new build flat will normally be leasehold, so read our leasehold guide as well.

Checklist: what to have ready

Gather these as soon as you reserve:

• The reservation agreement, price list and plot plan
• Details of every incentive, such as deposit contributions or included extras
• Your mortgage agreement in principle (a lender's provisional indication of what it may lend) and your broker's details
• Proof of your deposit and, if relevant, a gifted deposit letter
• The developer's expected completion date and your mortgage offer's expiry date
• The developer's answers on the warranty provider, who maintains the roads and open spaces, and the estate charge
• A snagging checklist for the pre-completion inspection

Next steps

New build deadlines are tight, so have a conveyancer lined up before you reserve. Get an itemised new build purchase quote, which shows any new build admin fee separately, or read about the new build purchase service. If you are buying a share from a housing association, see shared ownership explained.