Tool · New-build premium

What a new home asks. Against similar resales.

How far a new home’s asking price sits above what similar homes nearby have sold for, with how sure the estimate is, or why there is no figure.

Illustration, not advice No lender or product named Dated official figures, with their sources

The home

Development: Waterbeach
Plot: 41
Asking price: £220,000
Bedrooms: 1
Type: Flat
Floor area: Not available: not published

How the premium is worked out

Resale homes of the same type, with a bedroom count within one and a floor area close to this home’s, sold near it: HM Land Registry sales with their energy certificate’s floor area, never new-build sales.
Each sale moved to today’s prices with HomePortfolio’s repeat-sales index, built from homes HM Land Registry records selling more than once.
The middle half of those prices, per square metre where the floor area is known, is the band a similar resale home would sell in.
The asking price against that band is the premium, and after the builder’s cash offers too, with a confidence set by how many sales match, how alike and how recent.
Each month the method values thousands of resales whose price is already known, and the limits each confidence keeps to come from the error it measurably makes. Too few sales, too spread or too old, and there is no figure: the engine says why.

Worked out for

A 1 bedroom home at Waterbeach

Asking £220,000

New-build premium

Refused

A 1 bedroom home at Waterbeach

No estimate. The engine refused, and says why:

No matched resale sales within 3 km, fewer than the 5 the method needs
1 of the sales state no bedroom count, which HM Land Registry Price Paid Data alone never does, and the method matches on bedrooms, so these sales need bedrooms from an attributed source before they can count
Of 396 sales considered, set aside: 50 new-build, 18 category B, 318 another property type, 1 stating no bedroom count, 4 in a month the price index does not cover, 5 beyond 3 km

Method: measured on 3,351 resales from 2025-08-01 to 2026-07-31.

Sources: HM Land Registry resales, with EPC floor areas, via HomePortfolio (Open Government Licence v3.0); HomePortfolio new-build listings (Facts the builder publishes). Contains HM Land Registry data © Crown copyright and database right 2026. Contains public sector information licensed under the Open Government Licence v3.0.

Illustration, not advice: an estimate from past sales nearby, never a valuation of this home. No lender or product is named or recommended.