Buyers purchasing new-build properties off-plan in London have seen average gains of £26,000 before completion, according to analysis by Foxtons.
The estate agency’s data shows that new-build house prices across the capital have increased by an average of 0.23% per month over the past five years, with monthly growth rates reaching 0.4% in Bromley.
Price appreciation during construction
With the average new-build property in London priced at £535,157, and an estimated 21-month period between purchase and completion, buyers could see values rise to £561,412 by the time they take possession. This represents a 4.9% increase.
The data indicates that Islington shows the highest potential uplift at £40,244 before completion, whilst Richmond upon Thames shows gains of £35,268 during the build period.
Joel Ellis-Duffy, Sales Director New Homes at Foxtons, said: “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.”
Market context
The analysis comes as the off-plan market faces headwinds. Last month, Hamptons reported that off-plan sales had reached a 12-year low, with just 33% of new homes in England and Wales sold before construction was complete in 2025, down from 49% a decade ago.
The decline in off-plan sales has prompted concerns about the government’s ability to meet its housebuilding targets, as developers traditionally rely on early sales to secure financing for projects.
The data from Foxtons focuses on the London market, where property market dynamics have remained relatively stable despite broader economic pressures. However, the figures do not account for potential delays in construction timelines or changes in market conditions during the build period.
The analysis suggests that off-plan purchases may still offer value appreciation for buyers willing to wait for completion, though market conditions vary significantly by location. As with any property investment, potential buyers should consider the legal and financial complexities involved in off-plan transactions.
