December 2025 dwelling prices: the upswing cools, the new-build gap widens
Cotality's December index shows the broader upswing slowing to +0.5% for the month. Under the surface, new-build product is decoupling from the secondary market.
Cotality's December home value index rose 0.5% for the month, taking the calendar-year gain to 8.2%. The headline number is a cooling, but the composition matters more than the average: new-build product, particularly in the corridors targeted by the 5% Deposit Scheme price caps, continues to clear faster and at firmer pricing than secondary stock.
The decoupling is not yet conspicuous in the aggregate data. It will be by mid-2026.
What it means for portfolio construction
A cooling top-line index without a softening in new-build clearance is precisely the environment in which the right acquisitions outperform. Investors who underwrite to corridor-specific new-build absorption rather than capital-city headline growth are positioned for the next 18 months.
Dax Stanley
Founder & Principal Strategist, Hera Property. #1 international bestselling author of Real Estate Investing Using ChatGPT.