Ealing Extension Guide 2026: Planning Permission, Costs & Conservation Areas
Everything you need to know about extending your home in Ealing. SPD 4 design rules, which conservation areas have Article 4 directions, and realistic 2026 costs for west London.
Quick Answer
Ealing applies SPD 4 design guidance to all residential extensions. Most non-conservation areas qualify for permitted development, but Brentham Garden Estate has a comprehensive Article 4 direction removing virtually all PD rights. Costs run £58k–£92k for a typical rear extension or loft conversion inc VAT.
£58k–£88k
Rear extension 3m×5m
8–10 weeks
Planning time
Full PD removal
Brentham Article 4
Check your specific property constraints
Free Property CheckEaling: West London's Suburban Core
Ealing is one of the largest London boroughs by area, with a population approaching 360,000. Long marketed as the "Queen of the Suburbs," it sits in west London with strong transport links — the Elizabeth line from Ealing Broadway now puts central London under 15 minutes away. That connectivity has driven consistent demand for extensions over new-builds: homeowners are investing in their properties rather than moving.
The housing stock spans a wide range of eras and types. The southern and central areas around Ealing Broadway and West Ealing contain Victorian terraces and substantial Edwardian semi-detached and detached houses with large rear gardens — ideal for extensions. Hanwell and Southall have a high density of Edwardian terraces built from around 1900–1914. The interwar suburbs of Greenford, Northolt, and Perivale are dominated by 1930s semi-detached houses, many still with the original small rear kitchens and outbuildings that make rear extensions so appealing. Acton, in the east of the borough, has a mix of Victorian terraces and Edwardian streets.
High homeownership rates combined with this variety of extendable housing types means Ealing sees a high volume of planning applications for residential extensions each year. Understanding the borough's specific policies — particularly SPD 4, the Article 4 directions, and the conservation area framework — is essential before starting any project.
Ealing Local Plan and SPD 4
Ealing's planning framework for residential extensions is set out primarily in SPD 4 — Residential Extensions, a Supplementary Planning Document that provides detailed design guidance applied to all householder applications in the borough. SPD 4 does not override national permitted development rules, but it is a material consideration in all planning decisions and sets the council's expectations for design quality.
Ealing also adopted a new Local Plan covering 2024–2039, which sets the strategic planning policies for the borough including residential amenity standards and design expectations for extensions.
What SPD 4 Requires
SPD 4 covers the key design criteria that Ealing's planners assess on householder applications. The main requirements are:
Subordinate appearance
Extensions must appear subordinate to the original dwelling. For rear extensions, the roof ridge line should be set at least 0.5m below the ridge of the main house. A single-storey rear extension of up to 3m depth and 3m maximum height is the standard acceptable benchmark for most terraced houses.
Rear depth limits
For terraced and semi-detached houses, a 3m depth (from the original rear wall) is the standard acceptable depth for a single-storey extension without special justification. Larger extensions may be accepted on detached houses or where there is substantial separation from neighbouring properties, subject to the 45-degree daylight rule and amenity tests.
Side extensions
Side extensions must not project in front of the main building line and should be set back from the front elevation. In areas where properties have a uniform gap between houses, Ealing's planners are particularly attentive to side extensions that would erode the rhythm of the street. Side extensions should not exceed half the width of the original house.
Materials matching
Materials must match or be sympathetic to the existing house. For Edwardian and Victorian properties, this typically means matching brick (London stock or red facing brick depending on the original) and matching roof tiles or felt. Render extensions on brick houses will be assessed carefully and are not always acceptable outside conservation areas.
Conservation area compliance
In any of Ealing's 29 conservation areas, extensions must also comply with the relevant Conservation Area Character Appraisal and Management Plan. Extensions in conservation areas should not extend across the full width of the original dwelling.
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Ealing's Conservation Areas
Ealing has 29 designated conservation areas, covering a broad range of character including Victorian residential streets, Edwardian garden suburbs, village greens, and interwar development. If your property is in a conservation area, permitted development rights for rear and side extensions are removed — all extensions require full planning permission.
The key conservation areas affecting homeowners planning extensions are:
Brentham Garden Estate
One of the most tightly controlled conservation areas in London. Brentham is an Edwardian garden suburb built between 1901 and 1915, designated as a conservation area in 1969. It has a comprehensive Article 4 direction (see below) that removes virtually all permitted development rights. All external alterations and extensions require full planning permission, and the council applies the detailed Brentham Garden Estate Conservation Area Policy and Design Guide to all applications.
Extensions must respect the Arts and Crafts character of the original houses: render and painted timber details, steeply pitched roofs, projecting bays. Pre-application advice from Ealing Council is strongly recommended before preparing drawings.
Haven Green
The Haven Green conservation area in Ealing Broadway was first designated in 1982 and extended in 1993. It covers Victorian and Edwardian properties around the green near Ealing Broadway station. Extensions require planning permission and must respect the late Victorian and Edwardian character of the area. Matching brick, sash window patterns where relevant, and avoiding over-dominant additions to front elevations are the key design tests.
Ealing Green
Ealing Green conservation area covers the historic core of Ealing town, running along St Mary's Road and Ealing Green from Bond Street to St Mary's Church. Properties here include substantial Victorian and Edwardian houses. Rear and side extensions require planning permission and must respect the established architectural character of the area.
Hanwell Village Green
The Hanwell Village Green conservation area was first designated in 1974 and extended to include Campbell Road, Golden Manor and Hanwell Station. It preserves the historic character of Hanwell village. Extensions in this area need to respect the character of older housing stock and the village setting.
Pitshanger Village and Surrounding Areas
Pitshanger Lane and the surrounding residential streets form a distinct area of Edwardian and early interwar development. While Pitshanger Lane itself is primarily commercial, the residential streets nearby contain properties in the Ealing conservation area network. Check the Ealing Council conservation area map to confirm whether your specific address is designated.
Article 4 Directions in Ealing
Article 4 directions are the mechanism by which a local authority can remove permitted development rights in a specific area, requiring planning permission for works that would normally proceed without an application. In Ealing, the most significant Article 4 direction is on the Brentham Garden Estate.
Brentham Garden Estate Article 4 Direction
The Brentham Garden Estate Article 4 direction was made in 1976, shortly after the conservation area designation. It is one of the most comprehensive Article 4 directions in London — covering not just extensions but virtually all external alterations. Specifically, the direction requires planning permission for:
- Any side or rear extension to a dwelling house
- Erection of outbuildings and garden structures
- Painting of previously unpainted surfaces on front elevations
- Provision of hardstandings on road frontage and paving over of front gardens
- Erection, alteration or removal of a chimney on a dwelling house
If you own a property on the Brentham Garden Estate, you should assume that any external alteration or extension requires planning permission. Pre-application advice from Ealing's planning team is the essential first step before commissioning drawings.
Outside Brentham: Most other conservation areas in Ealing rely on the standard restrictions that automatically apply when a property is in a conservation area — permitted development rights for side and rear extensions are removed, but there is no separate Article 4 direction removing additional rights.
Check Ealing Council's Article 4 directions download for the complete and current list of directions in the borough.
Permitted Development in Ealing
Outside conservation areas and Article 4 areas, the national permitted development rules apply in Ealing. These allow single-storey rear extensions without a planning application within certain limits:
| Extension type | PD limit (depth) | Prior approval limit |
|---|---|---|
| Single-storey rear (terraced / semi) | 3m | Up to 6m (prior approval) |
| Single-storey rear (detached) | 4m | Up to 8m (prior approval) |
| Side extension | Half the width of original house | N/A |
| Single-storey rear height | 4m (3m if within 2m of boundary) | Same height limits apply |
Note that SPD 4 identifies 3m depth and 3m height as the standard benchmark for most Ealing terraced houses even under permitted development. While national rules may technically allow 3m depth at up to 4m height, the council's planners will use the SPD 4 criteria if a Lawful Development Certificate is challenged or a planning application is needed.
For extensions between 3m and 6m depth on a terraced or semi-detached house (or 4m to 8m on a detached house), the Neighbour Consultation Scheme (prior approval) applies — a simplified application to the council costing £120, with a 42-day decision period.
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Check now — it's free →Ealing Planning Application Process
All planning applications in Ealing are submitted through the Planning Portal (the national portal used by all English councils) or directly via Ealing's planning pages. The statutory decision period for a householder application is 8 weeks. In practice, straightforward extensions in non-conservation areas are typically determined within 8–10 weeks. Conservation area applications and more complex householder applications may take 10–13 weeks.
Pre-Application Advice
Ealing operates a pre-application advice service for householders and developers. For a householder extension in a conservation area or Article 4 area — particularly the Brentham Garden Estate — pre-application advice is strongly recommended and may save significant time and cost by identifying design issues before a full application is submitted. The service is chargeable; check the council's fees schedule for current rates.
What you'll need to submit
- Existing and proposed floor plans
- Existing and proposed elevations (all sides affected)
- Existing and proposed sections
- Location plan (1:1250) and site plan (1:500)
- Design and Access Statement addressing character appraisal requirements
- Materials schedule specifying brick type, mortar colour, roof finish
- Photographs of existing property and streetscene
Householder planning application: £528 (national fee for extensions to existing dwellings, as of 2025). Prior approval application: £120.
Design Guidance for Ealing's Housing Types
Ealing's SPD 4 expects extensions to respect the character of the original building and the street. The specific design approach varies significantly by housing type.
Edwardian terraces (Hanwell, Southall, Acton)
Edwardian terraced houses in Ealing typically have red or buff brick facades, projecting bay windows to the ground floor front, and slate or plain clay tile roofs. Many have original outriggers (single-storey rear additions) with their own shallow pitched roofs.
For rear extensions: match the brick (often a red or orange facing brick rather than London stock), use a flat roof with roof lantern or skylights for light, and keep the height to 3m to meet SPD 4 standards. Where the extension joins the original outrigger, the junction detailing is critical — careful weatherproofing and consistent eaves heights give a cleaner result.
1930s semi-detached houses (Greenford, Northolt, Perivale)
The 1930s semis that dominate Greenford, Northolt, and Perivale are typically constructed in light buff or sandy brick with pebble-dash or render upper sections, steel casement windows, and a side garage or passageway. The loft space is often large with a hip-to-gable conversion potential.
Rear extensions: brick-and-render combinations work well on 1930s semis. A flat roof extension with bi-fold doors opening onto the garden is the most popular configuration. For side extensions that incorporate or replace the garage, matching the original brick is important — 1930s sand-lime brick can be hard to source but reclaimed brick is a good alternative. Councils are generally supportive of side extensions on these plots where there is a clear garage or gap to infill.
Victorian terraces (Ealing Broadway, West Ealing)
Victorian terraces in the central Ealing area often have London stock brick facades, elaborate decorative brickwork to the front elevation, sash windows, and side returns. The side return — the narrow gap between the house and the boundary — is one of the most common extension opportunities in these streets.
Side return extensions that fill the gap and create a wider ground-floor kitchen are popular and generally well-received by Ealing planners where the original character is respected. Use London stock or similar yellow-grey brick, and consider a structural glass or polycarbonate roof panel over the kitchen-diner to bring light into what was previously a dark area.
Brentham Garden Estate (Arts and Crafts)
The Brentham houses are the most design-sensitive in the borough. They use render with exposed timber framing, clay or plain tile roofs with generous overhangs, and cottage-style proportions. Any extension must follow the Brentham Design Guide precisely: rendered walls, matching tile roofs, and traditional window proportions. Flat roofs, large areas of aluminium glazing, and modern minimalist detailing are rarely acceptable. Engage an architect experienced with Brentham before starting any project.
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Extension Costs in Ealing 2026
Ealing sits in the mid-range for London extension costs — above the outer east and south-east London boroughs but below the central premium zones (Camden, Islington, Kensington). As a west London borough with strong demand for quality residential work, expect experienced contractors to price at the higher end of the London mid-range. All figures below include VAT at 20%.
| Extension type | Size | All-in cost (inc VAT) |
|---|---|---|
| Rear extension (small) | 3m × 4m (12m²) | £48k–£72k |
| Rear extension (popular) | 3m × 5m (15m²) | £58k–£88k |
| Rear extension (large) | 4m × 5m (20m²) | £78k–£118k |
| Side extension (garage conversion / infill) | 3m × 5m–6m | £48k–£78k |
| Side return extension (Victorian terrace) | 1.5m × 7m–9m | £45k–£72k |
| Loft conversion (dormer or hip-to-gable) | 25–35m² | £58k–£92k |
All-in cost includes construction contract, architect, structural engineer, building regulations, and 10% contingency. Add £528 planning fee where a full application is needed. Conservation area premium: add 5–10% for brick matching, materials sourcing, and additional design work.
Additional costs to budget
Most Common Extension Types in Ealing
The most frequently built extensions in Ealing reflect the borough's housing stock:
Rear extension on Edwardian terrace
The most common project in Hanwell, Southall, and Acton. Edwardian terraces in these areas typically have an existing single-storey outrigger at the rear and a small garden. A full-width rear extension — absorbing the outrigger and extending to 3m from its rear wall — creates a large open-plan kitchen-diner. Under permitted development for most non-conservation properties. Budget £58k–£88k inc VAT for a 3m × 5m extension.
Hip-to-gable loft conversion on 1930s semi
The 1930s semis in Greenford and Perivale were built with hipped roofs that waste substantial loft space. A hip-to-gable conversion — squaring off the hip end and adding a rear dormer — is the standard configuration and can create a large master bedroom with en-suite. Under permitted development for most properties (the hip-to-gable conversion is treated as a roof alteration within PD limits). Budget £58k–£92k inc VAT.
Side return extension on Victorian terrace
Victorian terraces in Ealing Broadway and West Ealing frequently have narrow side returns — the L-shaped gap between the house and the rear boundary. Filling this gap extends the ground-floor kitchen into a wider, brighter room. A glass or polycarbonate roof panel over the new section brings light to what was previously a dark internal space. Typically requires planning permission if in a conservation area, or a Lawful Development Certificate in other areas. Budget £45k–£72k inc VAT.
Side extension incorporating garage (1930s plots)
Many 1930s semi-detached houses in Ealing have a garage to the side of the house on a wider plot. Converting or replacing the garage with a habitable extension creates a utility room, fourth bedroom, or home office without touching the rear garden. Within permitted development limits for most non-conservation properties. Budget £48k–£78k inc VAT depending on whether the garage is demolished and rebuilt or converted.
Practical Tips for Ealing Planning
Check Article 4 status before any design work
If you live on the Brentham Garden Estate, confirming the Article 4 direction applies to your property is step one. Engaging Ealing Council's pre-application service before commissioning an architect will save you from designing to PD standards and then discovering you need full planning permission with conservation-area-compliant drawings.
SPD 4 applies even under permitted development
While SPD 4 does not restrict what you can build under permitted development, if you apply for a Lawful Development Certificate (to confirm PD status) or if your extension falls just over PD limits and needs a planning application, SPD 4 criteria will be applied. Designing to meet SPD 4 standards from the outset — particularly the 0.5m ridge setback and materials matching — reduces risk of refusal.
Budget for brick matching on older properties
Ealing's Edwardian and Victorian housing stock uses a wide variety of brick types. The borough's planning officers are experienced at identifying poor brick matches. Sourcing reclaimed or closely matched new brick adds to the materials cost but is a requirement for conservation area work and good practice on any visible extension in older properties.
Start the party wall process early
Rear extensions on Ealing terraces and semis almost always excavate within 3m of a neighbouring boundary, triggering the Party Wall Act 1996. Serve notice at least 2 months before construction starts. If neighbours dissent or do not respond, the party wall process can add 2–3 months to your pre-construction timeline. Budget £800–£1,400 per neighbour.
Use a local architect familiar with Ealing planning
An architect who has submitted applications to Ealing Council before will know the officers, understand which design approaches are accepted, and can interpret the SPD 4 and conservation area appraisals accurately. This is especially valuable for Brentham Garden Estate applications, where detailed knowledge of the Design Guide is essential.
Frequently Asked Questions
Do I need planning permission for a rear extension in Ealing?
In most non-conservation parts of Ealing, a single-storey rear extension up to 3m deep (terraced/semi) or 4m deep (detached) qualifies as permitted development — no application needed. For depths of 3–6m (terraced/semi) or 4–8m (detached), a prior approval application is needed (£120, 42-day process). Any extension in a conservation area or on the Brentham Garden Estate requires full planning permission regardless of size.
What is SPD 4 and how does it affect my Ealing extension?
SPD 4 is Ealing Council's Supplementary Planning Document on Residential Extensions. It sets the design criteria planners apply to all householder applications: extensions must appear subordinate to the original house (ridge at least 0.5m below the main ridge), materials must match the existing building, and side extensions must not project forward of the building line. SPD 4 is a material consideration in planning decisions. For extensions under 3m depth on terraced houses, a flat roof with 3m maximum height meets the standard benchmark.
What does the Article 4 direction mean for Brentham Garden Estate?
The Brentham Garden Estate Article 4 direction (made in 1976) removes virtually all permitted development rights. Any side or rear extension, outbuilding, chimney alteration, or front garden hardstanding requires full planning permission. Applications must comply with the Brentham Garden Estate Conservation Area Policy and Design Guide, which specifies render walls, clay or plain tile roofs, and Arts and Crafts detailing. Pre-application advice from Ealing Council is strongly recommended before commissioning drawings.
How much does a rear extension cost in Ealing in 2026?
All figures inc VAT: a 3m × 5m rear extension (15m²) costs £58k–£88k all-in. A 4m × 5m (20m²) costs £78k–£118k. A side return extension on a Victorian terrace costs £45k–£72k. A hip-to-gable loft conversion on a 1930s semi costs £58k–£92k. Conservation area projects add 5–10% for materials sourcing and additional design work. These all-in figures include architect, structural engineer, building regulations, and a 10% contingency.
Which conservation areas in Ealing restrict extensions?
Ealing has 29 conservation areas. In all of them, permitted development rights for rear and side extensions are removed — planning permission is required. Key areas affecting homeowners include Brentham Garden Estate (also has Article 4), Haven Green (Ealing Broadway), Ealing Green, Hanwell Village Green, and areas around Pitshanger Lane. Check Ealing Council's conservation area map to confirm your property's status.
How long does planning permission take in Ealing?
The statutory period for a householder planning application is 8 weeks. In Ealing, straightforward extensions in non-conservation areas are typically decided within 8–10 weeks of validation. Conservation area applications, particularly in the Brentham Garden Estate, may take 10–13 weeks. A prior approval application (for 3–6m depth extensions) typically takes 6–8 weeks. Pre-application advice is recommended for conservation area projects to reduce the risk of delay.
What are the most popular extension types in Ealing?
The most common extensions in Ealing are: rear extensions on Edwardian terraces (Hanwell, Southall, Acton), hip-to-gable loft conversions on 1930s semis (Greenford, Northolt, Perivale), side return extensions on Victorian terraces (Ealing Broadway, West Ealing), and side extensions incorporating or replacing garages on 1930s plots. Each housing type has specific design requirements under SPD 4.
Summary
Ealing is a borough where most homeowners outside the conservation areas have good permitted development rights for standard rear extensions. The key check is whether you are in one of the 29 conservation areas or — specifically — on the Brentham Garden Estate, which has one of London's most comprehensive Article 4 directions.
SPD 4 provides clear design guidance that, if followed from the start of a project, makes planning applications more predictable. The 3m depth and 3m height benchmark for terraced houses, materials matching, and the 0.5m ridge setback rule are the three most important criteria to design to.
Costs are mid-range for London. Budget £58k–£88k all-in for a 3m × 5m rear extension, or £58k–£92k for a loft conversion. Add professional fees, party wall costs, and planning fees where needed, and allow 5–10% extra for conservation area projects.
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