New Build Mortgage Complications — Why Lenders Are More Cautious

New build mortgages are not straightforwardly the same as mortgages for second-hand properties. Lenders apply additional caution, specific policies, and different terms. Understanding this before you start saves significant frustration.

Why Lenders Are More Cautious With New Builds

Lenders' concerns with new builds include:

• **New build premium** — new builds are sold at a premium to reflect the modern specification and warranty. Lenders are concerned that the premium may not be sustainable in the resale market
• **Build delays** — mortgage offers expire; the property may not be ready in time
• **Valuation uncertainty** — on off-plan purchases, the valuation is based on comparables and plans, not an inspection of the finished property
• **Developer incentives** — incentives can inflate the apparent purchase price

Higher Minimum Deposits

Many (though not all) lenders require a minimum **10–15% deposit for new build properties**, compared to 5% for second-hand homes. This varies by:

• Property type (houses vs flats — most lenders are stricter on new build flats)
• Loan-to-value thresholds differ between lenders
• Apartment floor level (some lenders limit LTV on higher floors)

Check your chosen lender's specific new build policy early — some products that appear on comparison sites are not available for new builds.

Mortgage Offer Validity — The Timeline Problem

A standard mortgage offer is valid for 3–6 months. Many new build completions, particularly off-plan, take 12–24 months. This creates a mismatch.

Options:

• **Offer renewal/extension** — many lenders will extend on the same terms if the delay is the developer's fault. Not guaranteed.
• **Re-application** — you apply again when closer to completion. Risk: rates or affordability criteria may have changed
• **Specialist new build lenders** — some lenders offer 24-month offer validity specifically for new build off-plan purchases. A specialist new build broker will know who these are

Incentives and the Loan-to-Value Impact

Mortgage lenders require all developer incentives above 5% of the purchase price to be **declared**. When declared, the lender reduces the loan-to-value calculation accordingly.

Example: if you're buying a £300,000 new build with £18,000 of incentives (6% of purchase price), the lender calculates the mortgage based on a "net purchase price" of £282,000. If you're borrowing 90% (£270,000) of the £300,000, you're actually borrowing 95.7% of the net price — which exceeds some lenders' maximum LTV.

This can reduce the amount you can borrow, or require a larger deposit.

Off-Plan Down-Valuation Risk

When you exchange contracts off-plan, the lender's valuation is an estimate. At completion, they instruct a fresh valuation of the finished property. If the market has fallen, or if the finished product is valued below the agreed purchase price, the lender will only lend on the lower value. You must fund the shortfall from your own resources or renegotiate with the developer.

In a flat market, a 3–5% down-valuation is not uncommon. Plan for this possibility.

Choosing a Mortgage Broker

For new build purchases, use a broker with specific experience in new builds. They will know which lenders offer longer offer validity, which have the best rates for your LTV, which are most reliable on new build approvals, and how to present developer incentives correctly. Property Passport UK stores your mortgage and purchase documents in one place, simplifying re-applications if your offer needs to be renewed.