Mortgages/New Build

    New build timelines break ordinary mortgage offers

    Exchange is usually 28 days; completion can be a year away. The gap between them is where new build purchases go wrong.

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

    Buying off-plan means committing quickly and completing slowly. Developers typically want exchange within 28 days of reservation, while the property itself may not be finished for six to twelve months. Most mortgage offers last three to six months, so the offer can expire before you can use it. Handling that gap is the single most important part of a new build purchase, and it is why the choice of lender matters more here than almost anywhere else.

    The offer expiry problem

    If your offer expires before completion, it has to be re-issued — which means a fresh credit check and reassessment against current criteria and current rates. Some lenders offer extended validity specifically for new builds, holding the offer for longer than standard. Choosing one of those at the outset avoids a scramble later.

    Deposit and loan-to-value

    • Many lenders cap new build houses at a lower loan-to-value than second-hand homes
    • New build flats are often capped lower still
    • Developer incentives — paid stamp duty, cashback, white goods — can reduce the value a lender will lend against
    • Deposits paid to the developer at reservation are usually part of, not additional to, your total deposit

    The valuation question

    New builds carry a price premium in much the same way a new car does. Surveyors sometimes value below the purchase price, which leaves you to bridge the difference in cash. It is worth understanding what comparable resale properties on the same development are achieving before you commit.

    Warranties and what they cover

    Lenders require a recognised structural warranty — NHBC or an equivalent — usually running ten years. Check which one applies and that it's in place, as a missing or unrecognised warranty will narrow your lender choice considerably.

    Frequently asked questions

    How long will my mortgage offer last?

    Commonly three to six months, but several lenders offer extended validity for new builds. If completion is more than six months away, that extension should shape which lender you approach.

    Do developer incentives affect my mortgage?

    They can. Lenders often deduct the value of incentives from the purchase price when calculating loan-to-value, which effectively increases the deposit you need. Disclose them all — they will be on the disclosure form the lender sees.

    What if the property is valued below the price?

    The lender lends against the lower figure, so you would need to make up the shortfall, renegotiate with the developer, or withdraw. Knowing local resale values beforehand is the best protection.

    Worked example

    When the offer expires before the flat is finished

    An off-plan purchase reserved with a 28-day exchange deadline and a completion twelve months away.

    Exchange deadline from reservation
    28 days
    Expected completion
    around 12 months
    Typical mortgage offer validity
    3 to 6 months
    Gap to bridge
    6 months or more
    What that means
    a re-issued offer, a fresh credit check, and current rates

    Choosing a lender with extended new-build offer validity at the outset avoids re-applying against whatever criteria and rates exist a year later. It is the single most important decision in an off-plan purchase.

    Illustrative, using researched local price data. Not a quotation, an offer, or a statement of what any lender would agree — your own figures decide that.

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