The Risks of Buying a New Build

New build homes are attractive for good reasons. They come with a ten year structural warranty, energy efficient construction, no onward chain, and often a package of developer incentives.

For many buyers, particularly first time buyers, a brand new property that is ready to move into with nothing to repair or renovate is exactly what they want.

The buying process for a new build, however, works very differently from a normal purchase, and the biggest difference is timing.

On an ordinary purchase, exchange and completion usually happen close together, often on the same day or within a couple of weeks. On a new build, you may exchange contracts months before the property is finished. From that point, you are legally committed, but the date you actually complete may still depend on the build programme. That gap is where the risk lives.

Exchange happens early, and it commits you

When you reserve a plot you normally pay a reservation fee to hold the property, and the developer will then expect you to exchange contracts quickly, typically within about 28 days of reservation, and sometimes up to 56 days.

Some developers apply pressure to exchange even faster. That deadline exists to suit the developer’s cash flow and sales programme, not the buyer’s convenience.

The problem is that the property is often still being built when you exchange.

Instead of agreeing a fixed completion date, you usually agree to complete on notice. That means the developer gives notice once the property is finished and signed off, and you then have a short period to complete. You are therefore signing a binding contract before you know the actual completion date.

Build timescales slip, and you cannot control them

A developer may tell you the property will be ready in three months. In practice, new build timescales are notoriously fluid.

Material shortages, labour availability, weather, and delays in the local authority signing off the site can all push completion back. A build quoted at three months can slide to six, and a longer project can run to 12 or 18 months from the point you exchanged.

Because you have exchanged on completion on notice, you have very little control over that date.

Once the property is finished, the developer’s solicitor serves a notice to complete, and you are then usually required to complete within about 10 working days. You do not get to choose the timing, and the notice can arrive at short practical notice relative to the size of the commitment involved.

The mortgage offer clock is the real danger

This is the point that catches buyers out, and it is the heart of the risk.

A mortgage offer does not last forever.

A standard residential mortgage offer is typically valid for around six months. Some lenders offer dedicated new build products with an extended validity of nine months, and in some cases up to twelve, precisely because they recognise how often new build completions run late.

Now put the two timelines side by side.

You exchanged early and are committed to complete on notice. The build then overruns. If the property is not finished and ready to complete before your mortgage offer expires, the offer can lapse, and your solicitor cannot draw down the funds. The developer, meanwhile, may already have served, or be about to serve, notice to complete.

Some lenders will extend an offer, but an extension is not guaranteed. Where an extension is available it is often treated by the lender almost as a fresh application. That can mean new credit checks, a fresh affordability assessment, and sometimes a new valuation.

If your circumstances have changed since the original offer, for example a change of job, reduced income, new credit commitments, or a fall in the property’s assessed value, the lender may extend on different terms or decline to extend at all. Interest rates may also have moved, so even a successful re-offer can come at a higher rate than the one you originally secured.

The protections that should be in your contract

A well drafted new build contract does contain protection against runaway delays, and it is essential that your conveyancer explains these to you before you exchange.

Long stop date

This is the latest date by which the developer must deliver the property. If the build is not complete by the long stop date, you are generally entitled to withdraw from the contract and recover your deposit.

Some contracts call this a termination date. Check that a realistic long stop date is actually included, because not every contract is buyer friendly on this point.

Completion notice period

The number of working days you are given to complete once notice is served, commonly around 10 working days. Make sure this is workable given how long your lender needs to release funds.

Cooling off period

Under the New Homes Quality Code, a reservation agreement should include a 14 day cooling off period during which you can cancel and have your reservation fee refunded. Use that window for genuine due diligence rather than losing it to delay.

What you can, and cannot, do about it

It is important to be honest about the limits of what a buyer can do here, because some of the risk is simply built into how new build sales work.

If you are buying off plan, or early in the build programme, you cannot avoid the offer clock by waiting.

The developer requires you to exchange within around 28 days of reservation, and no responsible solicitor will let you exchange without a mortgage offer in place, because at exchange you become legally committed to complete.

That means your offer has to be secured up front, and the validity period starts running from that point, while the property may still be many months from completion. In that situation the delay itself is the risk, and it is largely outside your control.

Where a buyer genuinely does have a timing choice is on a plot that is already built or close to practical completion.

There, exchange and completion are relatively close together, so the offer clock is far less of a concern, and it makes sense not to apply so far ahead that the offer expires needlessly. On a true off plan purchase, that option is not really available to you.

So the mitigation is not about delaying the application. It is about lender selection, contract terms, and active monitoring from the outset.

Choose the offer validity to match the build timescale

This is the single most effective lever.

Where a long completion is expected, a lender offering a nine or twelve month new build product can be far more suitable than a cheaper headline rate on a six month offer that will expire before the home is ready. Getting this right at application is what protects you, because you cannot simply apply later.

Understand the offer expiry before you exchange, not after

Know the exact date your offer lapses and weigh it against the developer’s estimated completion date and, crucially, the long stop date. If the numbers do not line up, that is a conversation to have with your broker and solicitor before you commit, not once the offer is already running down.

Get the long stop date right

Since you cannot control the build, the long stop date is your contractual protection if the developer overruns badly. Make sure your conveyancer has secured a realistic one and has explained your exit rights before you exchange.

Instruct an experienced new build conveyancer

The 28 day exchange deadline, the long stop date, and completion on notice all need a solicitor who does this work regularly and can exchange in time without exposing you to unnecessary risk.

Monitor the offer against the build, and act early on an extension

Because the clock cannot be paused, the practical defence once you have exchanged is vigilance. Your broker, solicitor, and the developer’s sales team should be tracking the offer expiry against the build programme, so that an extension or a fresh offer can be arranged in good time, rather than in a scramble as the deadline arrives.