Reserve a new-build off-plan today and you could be more than £26,000 better off by the time you pick up the keys. Our latest research crunched the numbers on how much value the average new-build gains before you have so much as opened your own front door.
First though, the basics. Buying off-plan simply means reserving a brand-new home before it's finished being constructed, sometimes before a brick has been laid, working from the floor plans, show homes and specifications rather than walking round the actual property. You secure your place, agree a price, and wait for it to be built. It's how a large share of London's new-build homes are sold. Why do people buy this way? As the numbers below show, getting in early is often where the value lies.
Key takeaways
How off-plan buyers gain £26,255 before they move in
It's just maths. We looked at how much new-build prices have grown across London each month over the past five years, then set that against how long a new-build usually takes to finish once you have reserved it off-plan. Put the two together and you get the value a buyer stands to gain while the home is still going up.
The off-plan uplift
London new-build prices have climbed by an average of 0.23% a month over the last five years, rising to 0.4% a month in Bromley. Spread that across the 21-month build and the average new-build moves from £535,157 to £561,412... all while you're choosing your kitchen tiles.
Which London boroughs show the biggest off-plan gains
Wherever you buy in London, you stand to gain, because new-build prices have been rising right across the capital. How much you gain does vary, and it tends to be biggest in the higher-value central boroughs, where the same rate of growth is working on a larger starting price. Here is a handful of examples of what that can look like over a typical 21-month build.
📍 Gains on off-plan property value prior to move in
Take the City of London, where the average new-build sits at £1,070,944 today and could gain £55,291 over the build. Or Westminster, already averaging £962,418, where a buyer could still see £28,695 of growth during construction alone. For central buyers, off-plan is a way into a prime postcode at today's price, and letting the build period do some of the heavy lifting.
““International buyers, particularly across APAC markets, have long recognised the advantages of buying off-plan in London. It provides the opportunity to secure a property in a globally desirable market at today’s price point, whilst benefiting from potential value growth before completion.
We continue to see strong demand for high-quality London developments from overseas buyers who are taking a long-term view and who value the combination of stability, transparency and growth potential that the London market continues to offer."”
Amit Masrani
Sales Director – New Homes, Foxtons
The benefits of buying off-plan beyond price growth
The money is only half the story. Buying off-plan comes with a set of practical perks too. Here are the ones our buyers tell us make the difference.
🏠 A brand-new home
Everything box-fresh, a 10-year warranty behind it, and often the chance to pick your own kitchen or flooring.
⚡ Lower running costs
Most new-builds land an EPC rating of A or B, well ahead of the resale market. That means lower energy bills.
📅 Time to plan
The gap between reserving and completing gives you time to sort a mortgage, build savings and sell your current place.
🔑 First pick and incentives
Get in early and you get first pick of the best plots, views and layouts. Developers sometimes add in incentives too.
See off-plan in action: inside a landmark riverside scheme in South West London, and why buyers are reserving early.
Read the article →Learn more about the benefits of buying off plan.
Put the numbers and the perks together and the case for off-plan makes itself: a brand-new home, lower running costs, room to plan, and the pick of the best plots, all while the build period quietly adds value. The trick is choosing the right scheme and reserving before everyone else spots it.
“Buying off-plan has long been a strategic move for those looking to maximise value, and our analysis shows just how effective it can be in the current market.
Even without additional developer incentives, buyers can benefit from house price growth during the build period, which can translate into a notable uplift by the time the property is completed.
In a city like London, where entry prices can be a barrier, this also creates an opportunity for buyers to access more premium locations whilst still benefiting from long-term value growth.
Beyond the financial upside, it’s also about the quality and efficiency of the product itself. New-build homes are designed for modern living, with energy performance and ease of maintenance built in from day one.
”
Joel Ellis-Duffy
Sales Director – New Homes, Foxtons
Fancy getting in early? Let's find the home that's right for you.
Explore our New Homes developments →Sources:
Average off-plan completion time of 21 months sourced from Barratt Homes.
Average new-build values per borough sourced from the Gov UK House Price Index (February 2026, latest available).
Average monthly new-build growth applied per borough over 21 months to estimate the off-plan return.
Source: This article was written using Foxtons data and insight from our New Homes team, who work closely with developers and buyers across London every day. Grounded in local knowledge, it gives a clear, real-world view of what buying off-plan can look like for London buyers. If you have any questions on this article, email us to ask a Foxtons expert.
