What Fifty Valuations Say About One Street

Fifty of the fifty-four houses on Cotleigh Road, Romford RM7 carry a current Zoopla estimate, and forty-one carry a Rightmove one. This page ranks them and asks what the set says as a whole — which is a different question from what any single house is worth.

Every estimate was read from that property's own page and recorded with its capture date. No estimate on this page is calculated, indexed or averaged by this site.

The analysis of those estimates is this site's own: the medians, the quartiles and the two correlation coefficients below are arithmetic performed here on the providers' figures, and the working is shown so it can be checked. The distinction matters — the numbers in the table are the providers', the conclusions drawn from them are not.

These are automated model estimates, not formal valuations: no one has been inside these houses, and an automated valuation is not a survey, a mortgage valuation, or a price anyone has agreed to pay.

The headline numbers#

The two medians are £21,000 apart, which is the same gap that shows up address by address on Zoopla versus Rightmove. The figures below are Zoopla's, because it covers nearly the whole street where Rightmove covers three-quarters of it — but a median for this street is £425,000 or £446,000 depending on who you ask, and neither is the answer.

Half the street sits within £15,000#

The most striking thing in this data is how little of it there is. The middle half of Cotleigh Road — twenty-five houses — is valued between £439,000 and £454,000. Twenty-eight of the fifty fall between £430,000 and £450,000.

That is a £15,000 interquartile range on a £446,000 median: about 3.4 per cent. For fifty individually-modelled houses, on a street where the sale prices behind them span £63,995 to £530,000 and the sale dates span 1997 to 2025, that is a very narrow band.

Floor area explains almost none of it#

The obvious explanation would be size, and across the whole street size does appear to matter: for the forty-seven houses with a recorded floor area, the correlation between area and estimate is strong (r = 0.78), working out at roughly £1,360 per square metre.

That number does not survive a closer look. Four houses carry the entire relationship. Numbers 26, 9, 24 and 27 are all 111 sqm or larger and all sit near the top of the value range. Remove them and look only at the ordinary stock — the forty-three houses between 72 and 102 sqm, which is almost the whole street — and the correlation collapses to r = 0.107, at £207 per square metre.

In other words: the model separates the four big houses from everything else, and then within the remaining forty-three it barely differentiates at all. An extra ten square metres of floor space moves the estimate by about £2,000, which is less than the rounding on most of these figures.

This has a direct consequence for price per square foot as a way of valuing anything on this street. Within the main body of the stock it is close to meaningless: the numerator barely moves while the denominator does, so £/sqft becomes mostly a restatement of floor area.

That includes the £/sqft page on this site. Floor areas and price per square foot values houses here at a £432–£468 benchmark, £450 central. The two pages reach different conclusions from the same street, and this is the one with the correlation behind it: n=47, the working shown, the outliers identified. The £/sqft page now opens by saying so, and it is kept as a demonstration of what the industry-standard method produces here rather than as a valuation to rely on.

Where the two are used together, the honest reading is that £/sqft is a reasonable sanity check at the extremes of size and close to noise in the middle — which is where almost every house on Cotleigh Road sits.

The three houses that stand apart#

These are the only houses valued above £500,000, and they are the three largest. Below them the next highest is £471,000 — a £56,000 step down. The street has a clear top tier of three and a long flat body.

It is worth noting that two of the three are also where the models are least sure of themselves. Number 9 is rated only medium confidence, with a range of £483,000 to £590,000, and it is the widest Rightmove–Zoopla disagreement on the street. Number 26 sold for £530,000 in 2022 and has moved £7,000 since. Above half a million on a road of two-bedroom semis, the comparable evidence thins out and the estimates get less reliable, not more.

How the street has moved since it last sold#

The most useful thing about a street with 47 recorded sales is that every estimate can be read against what the house actually fetched. The table below does that: last sale, both providers' current estimates, and the change.

Read the change column with the year beside it — a house that sold in 1997 has had twenty-nine years to appreciate and one that sold in 2025 has had one. The per-address annualised figures make that comparable.

The last column links each address to the Zoopla and Rightmove pages its figures were read from, so any row can be checked against its source rather than taken on trust. Both providers revise as their models run, so a figure here is what the page said on the capture date, not a live feed.

Trends in the sale history#

Just over a third of the street has changed hands since 2020 — 17 of the 47 addresses with a recorded sale. Another 17 last sold during the 2010s, nine in the 2000s, and four not since the 1990s.

2021 was the busiest year on record here, with six sales, followed by four in 2022. That is a post-pandemic clustering visible on plenty of streets, and it matters for reading the estimates: a third of the addresses have a recent transaction anchoring them, and the rest do not.

The four houses that have not sold since the 1990s are where the models are least sure of themselves — numbers 12, 22, 35 and 48, last sold between 1997 and 1999. Two of them, 22 and 48, are the largest percentage gainers on the street at 584 and 559 per cent. Number 35 is the single widest disagreement between the two providers anywhere on Cotleigh Road: Zoopla £447,000, Rightmove £395,000, a £52,000 gap.

That is not a coincidence. An automated valuation is anchored by comparable recent transactions, and a house that has not sold in a quarter of a century offers none of its own. The estimates for those four are the softest numbers in the table, and the honest reading is that nobody — including both providers — knows what they are worth within £50,000.

Where these figures come from#

Sale prices behind them are HM Land Registry Price Paid Data, published under the Open Government Licence v3.0. The estimates are Zoopla's own and are reproduced for comparison; they are not open data and not this site's opinion. Every row above carries the links to the two pages it was read from, and the property market page sets the same addresses out with their Land Registry sale prices alongside.

Nothing here is financial advice.

Related#

• Growth since the last sale — the same houses, measured against what they last sold for
• Zoopla versus Rightmove — the two providers compared on the 39 houses where both publish an estimate
• Sources — every dataset used here