New Build Mortgages: A Buyer's Guide to Deposits, Incentives and Off-Plan Timing

The basic mortgage is the same as for any home, but a few things are handled differently on a new build:

• Deposit: Requirements vary. Some lenders offer higher loan-to-value lending on new-build houses, while others set a lower maximum loan to value on new-build flats. The deposit you need depends on the lender, the property type, the loan to value and any eligible scheme — there is no universal figure.
• Valuation: The lender's valuer checks the price against comparable sales. Incentives and asking prices on a new development can make the valuation less straightforward.
• Offer timing: If the home is not finished, the mortgage offer needs to last until completion (see off-plan timing below).
• Warranty: Lenders usually expect a recognised new-home warranty on the property.

We search a panel of 80+ lenders. Not every lender lends on every new-build property type, which is why checking the route before you commit matters.

A reservation fee usually takes the plot off the market for a set period, and the developer will often expect you to have a mortgage in principle and a solicitor in place quickly. Gather these details first:

• Developer, development and plot number — and a link to the plot listing if there is one.
• Asking price — and whether it has changed since launch.
• House or flat — lender criteria for flats can be tighter, especially in larger blocks.
• Tenure — freehold or leasehold, plus any estate management charge or service charge and what it covers.
• Reservation fee and deadline — how much, whether any of it is refundable, and how long you have to exchange.
• Expected build completion — the developer's estimate and how firm it is.
• Warranty provider — for example NHBC, LABC Warranty or Premier Guarantee.
• Developer incentives — anything offered, such as a deposit contribution, paid legal fees, upgrades or part exchange, and any conditions attached.
• Scheme participation — whether the developer has confirmed the plot is eligible for a specific scheme.

Incentives must be disclosed. The developer records them on a standard disclosure form for the lender, and your mortgage adviser needs to know about them too. Lenders treat incentives differently: some limit the total value they will accept, and some base the loan on the price net of incentives. Knowing this before you reserve avoids surprises at valuation.

Buying off-plan means agreeing to buy before the home is finished. The main mortgage risks are about timing:

• Offer expiry and extensions: Mortgage offers last a set period, which varies by lender. Some lenders offer longer validity for new builds or may consider an extension, but this is not guaranteed. If an offer expires, you may need to reapply on the rates and criteria available then.
• Construction delays: Build programmes can slip. Ask what happens under your contract if completion is later than expected.
• Valuation changes: If a new application or revaluation is needed, the value may come back different from the price you agreed.
• Exchange deadlines: Developers commonly set a deadline to exchange contracts after reservation. Once you exchange, you are legally committed and your deposit is at risk if you cannot complete.

That is why it helps to check the mortgage route — which lenders, what offer period and what deposit — before paying a reservation fee. The New Homes Quality Board's homebuyer resources cover the buying process, MoneyHelper's guide to buying and moving costs helps you budget for the expenses, and the New Homes Quality Board also explains the protections available when your developer is registered under the New Homes Quality Code.

Incentives can be valuable, but check what they are worth to you and how your lender will treat them. Common examples include:

• Deposit contribution: The developer puts money towards your purchase. Lenders differ on whether and how this counts towards your deposit.
• Help with costs: For example legal fees or a contribution towards stamp duty.
• Upgrades: Flooring, kitchen upgrades or fitted furniture.
• Part exchange: The developer buys your current home, subject to its own valuation and terms.

Some incentives depend on using a named solicitor or mortgage adviser, or on exchanging by a certain date. Read the conditions and compare the incentive with what you would pay otherwise.

• Mortgage Guarantee Scheme: A permanent government scheme since July 2025 that supports participating lenders offering 91–95% loan-to-value mortgages to eligible first-time buyers and home movers across the UK. It is not limited to new builds, and lenders apply their own criteria. See GOV.UK for the scheme rules, including the property price limit.
• Shared Ownership: Buy an initial share of 10% to 75% of a home and pay rent on the rest, subject to eligibility. See GOV.UK and our shared ownership guide.
• First Homes: An existing, separate scheme from Your First Home. Eligible buyers in England can buy certain homes at a discount of at least 30% to market value, with a price cap after discount and restrictions that pass on at resale. Availability depends on the local area and development. See GOV.UK.
• Deposit Unlock: An industry scheme for 95% mortgages on participating new builds. Its operators state that it closed to new completions in April 2026; outstanding offers at that point continue to be honoured.

For a wider overview, see our government homebuyer schemes guide.

Snagging survey

A snagging survey looks for defects and unfinished work in a newly built home — for example finishes, doors and windows, plumbing, electrics and external works. It is different from a full property survey. Report issues to the developer in writing.

Warranty

Most new homes come with a warranty from a provider such as NHBC, LABC Warranty or Premier Guarantee. Cover is often described as 10 years, with the builder responsible for certain defects in the first two years, but what is covered depends on the specific policy. Read your own warranty document.

New homes are sometimes priced above similar older homes nearby, reflecting their condition, energy efficiency and warranty. When you come to sell, your home is no longer new, and it may be competing with newer homes on the same development. There is no reliable universal percentage for this, so compare recent resale prices on the development or nearby, and be aware that a lender's valuation may come in below the asking price.

• Choose your conveyancer: You can use your own independent conveyancer. If an incentive depends on using the developer's recommended firm, understand the conditions and compare the overall cost and service.
• Book a snagging inspection before or soon after completion.
• Research the developer: Check whether it is registered with the New Homes Quality Board, read reviews and look at customer satisfaction information it publishes.
• Check charges: For leasehold homes or estates with management companies, ask for current and past charges.
• Check your budget: Try our affordability calculator and repayments calculator, and read our first-time buyer guide.

Tell us about the home you are considering and we will check which lenders could suit, how incentives may be treated and whether the timing works. Fill in what you know in the notes — anything missing can be covered on the call.

Your initial consultation is free. If a broker fee applies, your adviser will explain and agree it with you during research and before application. It is payable at application stage and is non-refundable.

Just want the numbers first? Use the affordability calculator or repayments calculator.

Your home may be repossessed if you do not keep up repayments on your mortgage.