---
title: "Mortgage on new build off plan"
description: "An off-plan purchase brings construction dates and mortgage offer expiry into the same decision. Explore valuations, delays, deposits and completion requirements."
url: "https://mortgagelane.com/guides/residential/mortgage-on-new-build-off-plan"
site: "Mortgage Lane"
collection: "guides"
date: "2026-07-03"
author: "Written by an adviser at Mortgage Lane"
category: "Mortgage guide"
reviewed: "2026-10-08"
reading_time: "4 min"
byline: "Written by an adviser at Mortgage Lane"
author_credentials: "CeMAP · FCA authorised firm"
language: "en-GB"
robots: "index,follow"
---

# Mortgage on new build off plan

An off-plan purchase brings construction dates and mortgage offer expiry into the same decision. Explore valuations, delays, deposits and completion requirements.

An off-plan purchase brings construction dates and mortgage offer expiry into the same decision. Explore valuations, delays, deposits and completion requirements.

[Off-plan mortgage](https://mortgagelane.com/definitions?term=off-plan-mortgage)

Residential

A mortgage arranged for the purchase of a new home before its construction is complete.

[Read the full definition of Off-plan mortgage](https://mortgagelane.com/definitions?term=off-plan-mortgage)

Back to overview

[Residential Mortgages](https://mortgagelane.com/mortgages/residential-property-mortgages)

Related definitions

[Off-plan mortgage](https://mortgagelane.com/definitions#def-off-plan-mortgage)

[Loan-to-value (LTV)](https://mortgagelane.com/definitions#def-loan-to-value)

## What is an off-plan new build mortgage?

An off-plan mortgage is a mortgage used to purchase a new build property before construction is completed, often at planning stage or early build phase. Buyers exchange contracts months, sometimes years, before the property is habitable, with the mortgage completing only once the property is finished and signed off.

This structure introduces timing, valuation, and lending risk, which is why off-plan mortgages are subject to stricter criteria than standard purchases.

## How off-plan purchases differ from standard new builds

Off-plan purchases involve:

- Early exchange of contracts
- Long gaps between exchange and completion
- Uncertainty around final value and market conditions
- Reliance on developer delivery and warranty completion

Lenders therefore underwrite not just the borrower, but the asset, developer, and build process.

## Loan-to-value (LTV) limits for off-plan properties

Most lenders apply lower LTV caps for off-plan purchases due to market risk. Typical limits are:

- 75-85% LTV for off-plan apartments
- 85-90% LTV for off-plan houses (lender dependent)
- Lower LTVs for city-centre flats and high-density schemes

The earlier in the build stage, the more conservative the LTV.

Deposit requirements and exchange timing

Buyers usually exchange with:

- 10-20% deposit
- Deposit paid on exchange, not completion
- Deposit held by the developer’s solicitor (or protected under warranty rules)

Some developers offer deposit contributions or incentives, but lenders may deduct these from the purchase price for valuation purposes.

## Mortgage offer validity and long-stop risk

Standard mortgage offers last 3-6 months, while off-plan builds can take:

- 6-12 months (houses)
- 12-36 months (apartment blocks)

This mismatch creates offer expiry risk, meaning:

- A re-application may be required
- Affordability is reassessed
- Credit profile must still meet criteria
- Interest rates may change

Some lenders offer extended offer periods specifically for new build and off-plan purchases. If the offer still runs out after exchange, our page on a [mortgage declined after exchange](https://mortgagelane.com/mortgages/mortgage-declined-after-exchange) covers the routes to completion.

## Valuation challenges on off-plan properties

Valuers assess:

- Comparable new build sales
- Local demand and oversupply risk
- Incentives offered by the developer
- Future market sustainability

If the valuation comes in below purchase price, the buyer must fund the shortfall or renegotiate.

Down-valuations are more common on:

- City-centre flats
- High-rise developments
- Schemes with heavy incentives

## New build warranties and lender acceptance

A recognised new build warranty is mandatory for mortgage approval. Commonly accepted warranties include:

- NHBC
- Premier Guarantee
- LABC
- Build-Zone
- Checkmate
- Protek
- BLP (Allianz-backed)

The warranty must be fully in place before completion, not merely promised.

## Developer approval and scheme exposure

Lenders assess:

- Developer track record
- Financial stability
- Build quality and planning compliance
- Total exposure to a single development

Some lenders cap the number of units they will lend on within one scheme to manage concentration risk.

## Off-plan mortgages for first-time buyers

First-time buyers can purchase off-plan, but face:

- Lower LTV limits than standard new builds
- Tighter affordability margins
- Greater scrutiny of deposit source
- Higher risk of market changes before completion

Schemes such as Shared Ownership or developer incentives may help, but lender treatment varies.

## Common reasons off-plan mortgage applications fail

Most failures are caused by:

- Valuation below purchase price
- Mortgage offer expiry before completion
- Incentives exceeding lender limits
- Warranty or developer not accepted
- Applying to lenders with off-plan restrictions

These are structural risks, not borrower errors.

## Regulatory position and consumer protection

Off-plan residential mortgages are fully FCA-regulated. Lenders must:

- Assess affordability at offer and completion
- Apply Consumer Duty
- Ensure foreseeable harm is mitigated, particularly around long delays

Buyers should also rely on solicitor checks around deposit protection and contract long-stop dates.

## Why specialist structuring matters

Off-plan mortgages are criteria-heavy and timing-sensitive. Successful outcomes depend on:

- Early lender selection
- Managing offer expiry risk
- Understanding valuation behaviour
- Aligning incentives with lender policy

Incorrect lender choice early in the process often leads to delays, reduced borrowing, or failed completions.

## Talk it through with an adviser

Speak to a Mortgage Lane adviser about your circumstances and the next steps.

Published: 2026-07-03

Last reviewed: 2026-10-08

Source: https://mortgagelane.com/guides/residential/mortgage-on-new-build-off-plan