Guide · 23 October 2026

Building costs and house prices in Ealing

Ealing is often called the Queen of the Suburbs, and much of it still looks the part: big Victorian and Edwardian houses around Ealing Broadway and the commons, garden-estate cottages at Brentham and Hanger Hill, long interwar streets in Greenford, Perivale and Northolt, and busier terraces in Acton, Hanwell and Southall. For anyone who already owns a house here, the question is usually whether to find more space by building or by buying, and the borough’s current price pattern makes that question sharper than it is in much of London.

The Census 2021 accommodation-type table (TS044, via Nomis) shows a fairly even split. Of Ealing’s 133,659 households, 23.4% lived in a terrace and 21.9% in a semi, both above the London shares of 21.3% and 18.6%. Detached houses are scarce at 5.1%, a little under London’s 6.1%. About 34.5% of households lived in a purpose-built block of flats (London: 40.3%) and 12.7% in a flat carved out of a converted or shared house, more than the London figure of 11.1%. That last number is a reminder of how many of Ealing’s larger old houses have already been split up, which matters later when we get to extensions, because permitted development rights don’t apply to flats.

Ealing house prices in August 2026

The UK House Price Index from HM Land Registry and the ONS, published on 21 October 2026, covers August 2026 (provisional). It puts Ealing’s average price at £589,875, 1.8% higher than a year earlier and 1.7% up on July. Over the same year London as a whole fell 2.2%, to £554,430, so Ealing is moving against the capital’s trend. It ranks 14th of London’s 33 local authority areas on this measure and sits about £35,000 above the London average. The borough’s peak was £593,867 in December 2022, and August’s figure is only about 0.7% below it. First-time buyers paid £493,727 on average, and buyers who had owned before paid £748,036.

The split is striking. Every kind of house in Ealing rose by between 3.6% and 3.8% over the year, while flats didn’t move at all. Houses here average more than the London figure for the same type, by roughly £259,000 for a detached house, £164,000 for a semi and £70,000 for a terrace, but the average Ealing flat is about £17,000 cheaper than the London average flat. The August release describes the same pattern across the capital, with houses rising and flats falling 5.0%. These are borough-wide averages from the HPI full data file. Monthly local figures can swing on a small number of sales (Land Registry recorded 145 Ealing sales for June 2026), they will be revised, and they can’t tell you what any one house is worth.

Is it cheaper to move or to extend?

On August’s averages, trading a terraced house for a semi in Ealing meant finding about £176,000 more, and moving from a semi to a detached house about £529,000 more. Stepping from a flat up to a terrace added roughly £309,000. Stamp duty, legal fees, a survey and removals would come on top, and because house prices here have been rising while flats stood still, those gaps have been widening rather than narrowing.

Nobody publishes building costs for Ealing alone, so the figures below are national ballparks. Checkatrade’s house extension cost guide, last updated in June 2026 and checked by estimators who are members of RICS and the CIOB, gives these UK ranges excluding VAT:

• £1,800–£3,000 per m² for a finished single-storey extension, which works out at £40,000–£56,000 for 20m² or £60,000–£84,000 for 30m²
• £45,000–£75,000 for a 25m² first-floor extension, such as over a garage
• £108,000–£180,000 for a 60m² two-storey extension
• £50,000–£95,000 for a 30m² loft conversion
• £100,000–£160,000 for a 40m² basement
• £8,500–£20,000 for a 15m² garage conversion

Checkatrade is clear that its costs aren’t location-based and that London and South East builders usually charge more, so expect Ealing quotes to land above these ranges, and add VAT. Even so, the comparison is lopsided. A loft or a good-sized rear extension sits well inside the £176,000 terrace-to-semi gap, and the half-million-pound step from a semi to a detached house is several times the top of the two-storey range. Building doesn’t turn a semi into a detached house, of course, and nobody can promise what an extension will add when you sell. Use these numbers to test your budget, not to forecast a profit.

What you can build without planning permission

The national permitted development rules, explained on the Planning Portal, usually allow a single-storey rear extension of 3 metres beyond the original back wall of a semi or terrace, or 4 metres for a detached house, without a planning application. Through the prior approval route, where neighbours are notified and can comment, those limits rise to 6 and 8 metres. A single-storey side extension can be up to 4 metres high and no wider than half the original house, and an extension of more than one storey can go back 3 metres if it stays at least 7 metres from the rear boundary. The loft conversion guidance allows up to 50 cubic metres of extra roof space on a detached or semi-detached house and 40 cubic metres on a terrace, with nothing projecting beyond the front roof slope.

None of this applies to flats or maisonettes, which rules out a lot of Ealing’s converted houses, and the rights are narrower in conservation areas. When you think a project qualifies, a Lawful Development Certificate gives you proof for a future buyer. Either way, the work needs building regulations approval, and the council’s planning and building control pages explain how to apply.

How Ealing judges extensions that need permission

Applications are decided against the London Plan and Ealing’s current development plan, which includes the Development (Core Strategy) document of 2012, the Development Management and Development Sites documents of 2013, and neighbourhood plans for Central Ealing (2017) and West Ealing (2018). The older Residential Extensions SPD is kept as interim guidance.

A more recent document is worth reading before you brief a designer. The Ealing Character Study design guidance (November 2022) presents itself as principles rather than fixed rules, but it is specific about extensions. It says that, as a general guide, a rear extension of 3.5 metres in depth is likely to be acceptable, and anything deeper needs a sound design justification showing that neighbours are protected. Side extensions should be stepped back from the front, with about half the depth of the house generally acceptable. On semis with hipped roofs it advises against a hip-to-gable loft where the neighbour’s hip remains, and it prefers rear dormers to new windows on the front roof. It also asks extensions to keep the front building line and to pass the 25° and 45° tests for neighbours’ light.

A new Local Plan for 2024–2039 was submitted for examination on 18 November 2024. In a letter of 18 June 2026 the inspectors said it isn’t sound as submitted but could be made sound with main modifications, which the council has to consult on. It has not been adopted, so check which policies apply when you apply.

Conservation areas and Article 4 directions

Ealing Council’s conservation areas page says there are 30 conservation areas in the borough, and its conservation area map lets you check an address. Within them the council identifies “positive contributors”, buildings that add to an area’s character, and treats changes to them with extra care.

According to the council’s guide to conservation areas, six of them have Article 4 directions that take away some permitted development rights:

• Bedford Park, where extensions, roof alterations, porches, outbuildings and pools, hard surfaces and aerials need permission.
• Brentham Garden Estate and Hanger Hill Garden Estate, where controls cover windows and doors, porches, roof materials, chimneys, garages, hardstanding, front boundaries and painting.
• Hanger Hill (Haymills) Estate, covering front elevations, roof slopes and rooflights, porches, front hardstanding, painting, chimneys and side or rear outbuildings.
• Churchfields, where the direction on Half Acre Road covers roof additions.
• Ealing Town Centre, where it applies on The Grove.

Separately, HMO Article 4 directions mean that turning a family home into a small house in multiple occupation has needed planning permission in Perivale ward since 30 October 2024, and across the rest of the borough (outside the Old Oak and Park Royal area) since 14 November 2025. If you plan to extend a house in order to let it by the room, that is a planning question as well as a building one.

Garden rooms and the outbuilding trap

Ealing has a long-running problem with sheds and garages being turned into homes. The council’s illegal outhouses page explains that outbuildings under a certain size may not need permission as long as nobody lives in them, and asks residents to report suspected illegal dwellings. A garden office, gym or studio can be a sensible alternative to an extension. But be wary of any builder who suggests fitting one out with a bedroom, shower and kitchen and letting it, because that is exactly what the council investigates.

Basements, rivers and flood risk

The Planning Portal says a new basement is likely to need planning permission, and digging near a neighbour’s foundations brings in the party wall process. The River Brent runs through the borough, so check your address on the government flood map for planning and ask your designer about ground conditions and surface water before committing to any work below ground.

Party walls

With nearly half of Ealing households in a semi or a terrace, most projects involve a shared wall. Cutting steels into a party wall, building a new wall on the boundary or digging foundations close to next door can all need notice under the Party Wall etc. Act 1996, and the excavation rules can apply to detached houses too. GOV.UK’s guidance explains each type of notice and includes example letters. If a neighbour dissents, surveyors draw up an award setting out how the work will be done. Talking to them before the notice arrives usually saves time and money.

Checking a builder

Treat cold callers, requests for a large cash deposit and single round-number prices with suspicion. A reputable firm will give you a written, itemised quote and contract, link payments to completed stages, show proof of insurance and recent work you can visit, and tell you who will sign off the building regulations, whether that is the council or a registered building control approver.

You can look for registered tradespeople on TrustMark, work through Citizens Advice’s checklist before building work, and report a rogue trader to your local Trading Standards office.

Figures change: get quotes before you decide

House prices here are UK HPI averages for August 2026. They are provisional and will be revised, and the September 2026 figures are due on 18 November 2026. Building costs are Checkatrade’s national figures, last updated in June 2026, not Ealing quotes, and London work often costs more. Household figures come from Census 2021 (census day was 21 March 2021). Planning details are from Ealing Council’s pages and documents as they stood when we checked them, and the new Local Plan could change some policies once it is adopted. Check the rules for your own address, and get at least three itemised quotes based on proper drawings before you decide whether to build or move.

Sources: UK House Price Index England: August 2026 (GOV.UK); UK HPI data downloads, August 2026 (full file, Ealing E09000009); ONS local house prices: Ealing; Census 2021 TS044 accommodation type (Nomis); Checkatrade: house extension costs; Planning Portal: extensions; Planning Portal: loft conversions; Planning Portal: basements; Ealing Council: development plan; Ealing Council: interim guidance (Residential Extensions SPD); Ealing Character Study: design guidance, November 2022; Ealing Council: new Local Plan; Ealing Council: Local Plan examination news; Inspectors’ letter on main modifications; Ealing Council: conservation areas; Ealing Council: about conservation areas (Article 4); Ealing conservation area map; Ealing Council: HMO Article 4 directions; Ealing Council: illegal outhouses; Ealing Council: building control; GOV.UK flood map for planning; GOV.UK: Party Wall etc. Act guidance; TrustMark; Citizens Advice: before building work; GOV.UK: find local Trading Standards. Data checked 23 October 2026.