Where the number comes from

HomeSignals calculates a fair market price for London properties using real sold data, floor area, and the UK House Price Index — so you can see at a glance whether a listing is priced fairly.

Based on HM Land Registry · EPC register · UK House Price Index

Three steps to a fair price

STEP 01

We aggregate listings daily

Every London property listed across major portals is ingested, deduplicated, and stored — including price changes over time. Around 80,000 listings are tracked at any moment.

STEP 02

We calculate a fair price

For listings with a confirmed floor area from the EPC register, we combine nearby Land Registry sold prices per m², apply the current HPI index, and multiply by the property's size.

STEP 03

You see the verdict instantly

Every valued listing shows the delta in plain English — below, about right, or above fair value — and the exact pound gap, so you know before you book a viewing.

How fair price is calculated

Fair price =

avg_price_per_m² × hpi_index × floor_area_m²
avg_price_per_m² Average sold price per square metre from HM Land Registry transactions within the same postcode area, over the past 24 months.
hpi_index UK House Price Index adjustment factor for the local authority, bringing historical sold prices forward to today's market conditions.
floor_area_m² Confirmed floor area in square metres from the Energy Performance Certificate (EPC) register — the only independent, government-verified source.

We only calculate a fair price when a floor area is available. We never estimate or interpolate.

Four states, one honest signal

The verdict only appears when a listing publishes its floor area — giving us enough data to calculate a credible fair price. We never guess.

Under value
Asking price is meaningfully below our fair price. The gap is shown in pounds. A good buy signal worth investigating further.
About right
Asking price is within a reasonable margin of our fair price. Neither a standout deal nor overpriced.
Over value
Asking price exceeds our fair price estimate. Caution, not alarm — the gap is shown so you can decide whether to negotiate or walk away.
Not valued
No floor area is available for this listing. We can't calculate a fair price, and we say so clearly rather than showing an unreliable estimate.

Common questions

What is a HomeSignals fair price?

It's our estimate of a London property's true market value, calculated from HM Land Registry sold prices per square metre in the local area, adjusted by the UK House Price Index, and multiplied by the property's EPC-verified floor area.

Why are some listings not valued?

We only calculate a fair price when a listing has a confirmed floor area from the EPC register. If that data isn't available, we show the listing as "not valued" rather than guessing.

Is the fair price verdict free?

Yes. The fair price verdict is free on every valued London listing. Premium adds the ability to filter and sort search results by how far under fair value a property is, plus alerts.

How often is the data updated?

Listings and fair price calculations refresh daily from our data pipeline.

Start searching with fair price

The fair price verdict is free on every London listing, forever.