A new estate went up near you. Flats and terraces pay for it, semis barely notice

Research by ValuQ: we matched 11,270 Essex homes that sold twice, once before the 2015 to 2022 building wave and once after it, and compared what happened to homes in the postcode sectors that took the most new building against same-priced, same-type homes in the sectors that took almost none.

ValuQ Property Watch. In January, an analysis of 14 areas of England reported that homes within half a mile of major new developments lost value while homes further away gained, with one West Yorkshire village down 18.5%. If a site has been allocated near you, that is the number now sitting in your head. We measured the same question across one whole county, using a method that cannot be moved by which homes happened to sell.

How much does building nearby actually cost a neighbouring home?

About four percentage points of growth over eleven years. We tracked the same homes selling twice, so no change in the mix of properties sold can distort the result, and we compared only homes that started from a similar price, because cheaper areas grew faster everywhere and building did not fall evenly across price levels.

On a home bought for £200,000, a 4.2 point gap is about £8,500 of growth that did not arrive over eleven years. That is a real cost and worth knowing. It is not the collapse people fear at planning meetings, and it is a long way from the 18.5% fall in a single village that carried the story in January. That village was the worst case in a study of 14 selected sites, not the typical outcome.

Which homes actually carry the cost?

This is the part the county average hides, and it is the part that matters if you are the one selling.

Flats and terraces show gaps four times the size of the semi-detached gap. The explanation that fits is competition for the same buyer. A new estate sells homes that compete most directly with smaller, cheaper existing stock, and a buyer weighing a second-hand terrace against a new house with a warranty and no chain has a genuine alternative. An established semi on a settled street competes with what gets built far less directly.

So is my home going to lose value?

In roughly a third of cases the opposite happened. Of the 63 Essex sectors that took the heaviest building, 20 grew faster than the median for comparable areas at their price level. Comparing the busiest and quietest sector inside each district, only 6 of the county's 14 districts show the built-up sector growing less. Eight show the reverse.

• Harlow is the widest negative: its most-built sector grew 63.4% while the quietest corner of the same town grew 88.7%.
• Thurrock is the widest positive: RM15 5 took heavy building and its existing homes grew 106.9%, the strongest figure in the county table.
• Where building arrives alongside transport or regeneration investment, existing owners can end up ahead. Where it arrives without it, they can end up behind.

What happened in Basildon?

The county pattern does not appear in the borough at all. SS16 5, around Langdon Hills and Vange, took more new building than anywhere else in Basildon and its existing homes grew 100.8%, among the strongest in the borough. The two weakest performers, both in Billericay, took almost no building and started from the highest prices in the table.

In Basildon the clearer signal is the starting price, not the building. The cheapest sectors grew the most. In a town where prices started low, the effect of a new estate was easily outweighed by everything else moving the market.

Every planning objection says the estate will knock thousands off local homes. Across a whole county the honest answer is about four points over eleven years, it falls mostly on flats and terraces, and in one area in three it did not happen at all. Owners deserve the number, not the folklore. Evren Ergin, founder of ValuQ.

How we did this

ValuQ used HM Land Registry Price Paid data, standard open-market sales, for Essex, Southend-on-Sea and Thurrock, covering 1995 to May 2026. For each postcode sector we measured the share of sales between 2015 and 2022 that were new builds. We then matched every home that sold twice, keeping only pairs bought between 2010 and 2014 and resold from 2022, at least seven years apart, where both sales were of existing homes of the same property type. That gives 11,270 matched pairs, of which 10,384 sit in the 171 sectors with enough sales to report. Median holding period was 11.1 years.

Two honest caveats. This is an association, not a proven cause: land gets released where it is available and permitted, and those places may differ from quiet places in ways this data cannot see. And a postcode sector holds roughly two to three thousand addresses, so this measures how much building happened around a home rather than how close it sits to one estate. That will understate the effect on the houses directly facing a site.

What should you do if a site has been allocated near you?

Get real evidence before you price anything. When a lot of new homes have sold nearby, the local sold-price record gets noisy: new-build prices sit above second-hand prices for the same space, developer incentives are not always visible in the recorded figure, and recent sales can be dominated by homes unlike yours. That is when a single opinion of value, from any one source, is least reliable. ValuQ gives UK homeowners free, side-by-side property valuations from competing local estate agents, anonymously until you choose to connect. If those valuations come back close together, that tells you something. If they come back far apart, that tells you more. Free for homeowners, always.