Haringey Extensions 2026: Planning Guide, Costs & Permitted Development

Haringey: What Kind of Borough Is It?

Haringey is a north London borough stretching from the leafy slopes of Highgate and Muswell Hill in the west to the dense urban fabric of Tottenham and Wood Green in the east. The contrast between these two halves is pronounced and has a direct bearing on planning for home extensions.

Crouch End, Muswell Hill, Highgate, Hornsey, and Stroud Green are dominated by Victorian and Edwardian terraces and semis — bay-fronted properties with original stock brick, slate roofs, and typical London rear gardens. These areas are among the most sought-after in north London and carry a high density of conservation designations. The council has applied Article 4 directions across a significant portion of this western half of the borough, removing many permitted development rights and requiring planning permission for alterations that homeowners elsewhere might do without any application.

Tottenham and Wood Green, in the east, have a more mixed housing stock. Victorian terraces sit alongside inter-war council housing, 1930s semis, and post-war developments. Conservation area coverage is more selective here — focused on specific historic corridors such as Tottenham High Road and Noel Park — rather than blanketing whole neighbourhoods as it does in the west.

Haringey Local Plan and Extensions Policy

The Haringey Local Plan is the primary planning document setting out how development in the borough is assessed. Strategic Policies were adopted in 2013 and the Development Management Policies DPD in 2017. The council is progressing a new Local Plan, but in the meantime, the 2017 document and its associated guidance remain current. All householder planning applications are assessed against these policies.

Unlike some London boroughs, Haringey does not publish a single borough-wide Alterations and Extensions SPD. Design guidance is instead embedded within the Development Management Policies DPD and area-specific character appraisals for each conservation area. The Supplementary Planning Documents page lists available guidance, including the South Tottenham residential design guide, which supplements the general policies for that part of the borough.

Core design principles for extensions in Haringey

• Subordinate scale: Extensions should remain subordinate to the original building in height, width, and massing — this is particularly important for side extensions which could otherwise erode the character of a terrace
• Materials: In conservation areas, materials must respect the original building fabric — matching or complementary stock brick, appropriate roof coverings, and heritage-grade glazing details
• Neighbour amenity: Extensions must not cause unacceptable loss of daylight, outlook, or privacy to adjoining properties — the 45-degree rule and BRE daylighting guidelines are applied
• Street character: Side and front extensions visible from the street must respect the established building line, the pattern of gaps between buildings, and the overall rhythm of the streetscape

Conservation Areas and Article 4 Directions

Haringey has 29 designated conservation areas, designated over more than four decades. Several of these sit in the most popular residential parts of the borough — Crouch End, Muswell Hill, Highgate, Hornsey, Stroud Green, and Fortis Green — which means a large proportion of the borough's Victorian and Edwardian housing stock falls within a conservation area. In these locations, the council has applied Article 4 directions that remove permitted development rights for external alterations. This is one of the most important things to establish before starting any extension project in Haringey.

Crouch End Conservation Area

The Crouch End Conservation Area covers the core of this popular neighbourhood, including the Broadway area and the surrounding Victorian streets. The area is characterised by late-Victorian terraces and semis — typically bay-fronted two-storey properties in yellow London stock brick, with original sash windows, slate roofs, and front boundary walls. Article 4 directions apply here, targeting the removal of original architectural features that would otherwise be permitted development. Extensions in Crouch End require planning permission in most cases, and officers will expect proposals to respect the scale, materials, and character of the existing building.

Muswell Hill Conservation Area

Muswell Hill has a distinctive Edwardian character, with the shopping Broadway and surrounding residential streets developed largely between 1896 and 1914. The residential streets — Muswell Road, Queens Avenue, Alexandra Park Road — contain Edwardian terraces and semis with red brick and render facades, bay windows, and prominent rooflines. The conservation area character appraisal emphasises the importance of retaining the consistent street pattern and the rhythm of gable features and bay windows. Rear extensions are the most common project type here and can be approved where they are appropriately scaled and use sympathetic materials.

Highgate Conservation Area

Highgate is one of Haringey's most sensitive conservation areas, with a concentration of Georgian and early Victorian buildings around Highgate Village. The area straddles the boundary with Camden, and some properties fall within Camden's planning jurisdiction. For properties within Haringey's portion of Highgate, the design bar is high — extensions must be of the highest quality, demonstrating a clear understanding of the historic context. Pre-application engagement with Haringey officers is strongly recommended before any work in this area.

Other Key Conservation Areas

Permitted Development in Haringey

Where Article 4 directions do not apply — primarily in the more suburban or post-war parts of the borough such as parts of Tottenham, Wood Green (outside conservation areas), and Bounds Green — the standard national permitted development rules for householders apply. Within conservation areas, even without a specific Article 4 direction, some permitted development rights are automatically restricted by the conservation area designation itself — notably cladding and certain roof alterations.

The Planning Process in Haringey

Standard householder planning applications in Haringey are decided within 8 weeks of validation. Major applications take longer. Most householder extension applications are decided by officers under delegated powers and do not go to committee. Haringey offers a fast-track service for householder and lawful development certificate applications, which can reduce the decision period for straightforward cases.

Pre-application advice

Haringey provides a pre-application advice service for householders. Fees in 2025–2026 are:

• Quick written advice (no meeting): £300
• Standard householder service (with meeting): £480
• Comprehensive householder service: £844
• On-site advice: £230

Pre-application advice is strongly recommended for extensions in the Crouch End, Muswell Hill, Highgate, and Noel Park conservation areas. Officers will indicate what scale, design, and materials they are likely to support, reducing the risk of refusal.

Application fees (2026)

• Householder application: £258 (England, from December 2023)
• Prior approval (large rear extension): £120
• Listed building consent: No charge (fee-exempt)

Design Requirements by Neighbourhood

Crouch End and Stroud Green (N4, N8)

The Victorian and Edwardian terraces of Crouch End and Stroud Green — centred on N8 postcodes and the fringes of N4 — are the most typical canvas for extensions in this part of Haringey. These are bay-fronted two- and three-storey properties in yellow or buff stock brick, with slate roofs, original sash windows, and front gardens that are increasingly paved over (though the council resists this). Rear extensions are by far the most common project type. A single-storey rear extension extending the kitchen-dining area into the garden typically 3–4m deep, with a lean-to or flat roof and large rear glazed opening, is the standard approach.

Officers in the Crouch End conservation area expect materials to either match the original building fabric — stock brick, matching mortar joints, appropriate roof tiles — or take a clearly contemporary approach using high-quality contrasting materials at the rear. Dark-framed glazing, charred timber cladding, or weathered steel that reads as a deliberate new addition, set against the original rear elevation, can be approved where it is evident the design is of good quality and the contrast is handled well.

Muswell Hill (N10)

Muswell Hill's Edwardian properties are broadly similar in form to Crouch End's Victorians but tend to have slightly larger footprints and more generous rear gardens. The conservation area character appraisal identifies the red brick and render facades, the prominent bay windows and gable features, and the consistent rooflines as the defining elements. Extensions should respect these proportions. Loft conversions are common here — the larger original roofspaces of Edwardian properties lend themselves to dormer conversions — but dormers visible from the street or from public viewpoints require planning permission within the conservation area.

Hornsey and Alexandra Park (N8, N22)

The streets around Hornsey and the slopes below Alexandra Palace mix Victorian terraces with Edwardian semis and some inter-war housing. Alexandra Palace and its parkland create a strong backdrop and contribute to the character of the surrounding conservation area. Extensions in these streets are assessed against the conservation area appraisal, which emphasises the views to and from the Palace as an important characteristic. Extensions that would be visible in these views are particularly sensitively assessed.

Tottenham and Wood Green (N15, N17, N22)

Outside the conservation areas, the Victorian terraces of Tottenham and the more mixed housing stock of Wood Green operate under standard permitted development rules in many streets. This means that for a semi-detached or terraced property in, say, Bruce Grove or West Green Road outside a conservation area, a single-storey rear extension of up to 3m depth may be possible without planning permission, subject to the usual height and materials conditions. The key is to verify whether your street falls within a conservation area or Article 4 zone — the Tottenham High Road and Noel Park conservation areas both have planning restrictions that catch homeowners by surprise.

Extension Costs in Haringey 2026

All costs below are inclusive of VAT at 20% and reflect 2026 market rates for north London contractors. Haringey sits in the mid-to-upper range of London borough pricing — comparable to Islington and Hackney, somewhat above outer south-east suburbs, but below the most expensive central and west London boroughs. The western, more affluent half of the borough (Crouch End, Muswell Hill, Highgate) tends to see slightly higher contractor rates than the eastern half (Tottenham, Wood Green). Conservation area work typically adds 10–15% to accommodate premium materials and additional detailing.

Additional professional and statutory costs

• Architect or architectural designer: £4,500–£14,000 (typically 8–12% of build cost)
• Structural engineer: £1,500–£3,500
• Planning application fee: £258 (householder)
• Party wall surveyor: £1,500–£3,000 per adjoining owner (common with Haringey terraces)
• Building Control: £800–£2,000 depending on project scale
• Pre-application advice (Haringey): £300–£844 depending on service level

Common Extension Types by Neighbourhood

Crouch End and Stroud Green: side returns and rear extensions

The narrow Victorian terraces of Crouch End and Stroud Green have a side passage alongside the ground floor that is one of the most valuable spaces available for extension. Infilling this side return — typically 1.2–1.8m wide and running the full depth of the ground floor — creates an L-shaped footprint that dramatically improves the kitchen and dining layout. Combined with a rear extension, this wraparound approach is the most sought-after project type in these streets. Expect to budget £90,000–£138,000 for a full wraparound including planning, professional fees, and construction.

Muswell Hill: loft conversions and rear extensions

The larger Edwardian properties in Muswell Hill lend themselves particularly well to loft conversions. The roof spaces are generous, and dormer loft conversions adding a master bedroom with en-suite — or a bedroom and bathroom — are very common projects. These require planning permission within the conservation area but are generally supported where the dormer is positioned to the rear and does not disrupt the roofline when viewed from the street. Single-storey rear extensions remain popular too, typically extending the kitchen-dining room by 3–4m with a full-width glazed rear opening.

Noel Park: careful interventions in a model estate

The Noel Park Conservation Area in Wood Green presents particular constraints. The planned estate layout, consistent brick detailing, and uniform terrace character mean that extensions need to be very carefully designed. Rear extensions that are invisible from the public realm can be approved, but any alteration visible from the street or from within the estate requires a high standard of design justification. Homeowners in Noel Park are strongly advised to seek pre-application advice before investing in detailed drawings.

Tottenham and Wood Green: more flexibility outside conservation areas

In the parts of Tottenham and Wood Green that sit outside the conservation area and Article 4 zone, homeowners have significantly more flexibility. Victorian terraces in these streets can often extend under permitted development — a 3m deep single-storey rear extension may proceed without any planning application for semi-detached and terraced properties. For properties with larger rear gardens, the prior approval route extends this to 6m (semi/terrace) or 8m (detached). This makes Tottenham and Wood Green among the more straightforward parts of Haringey for carrying out extensions without formal planning applications.

Planning Tips for Haringey Extensions

• Verify your conservation area and Article 4 status first. With 29 conservation areas in the borough, there is a high chance your property is affected. Use Haringey's Article 4 map or our free property checker to confirm before investing in any design work.
• Highgate properties: check your borough. The Highgate Conservation Area straddles Haringey and Camden. If your property falls within Camden's boundary, your planning application goes to Camden Council, not Haringey. The design expectations are similar but the officer teams, policies, and pre-application services differ.
• Use pre-application advice in sensitive locations. For Crouch End, Muswell Hill, Noel Park, and Highgate conservation areas, a £300–£480 pre-application advice service is well worth the cost. Officers will indicate likely approval, flag any concerns about materials or scale, and reduce the risk of a refusal that delays your project by months.
• Allow time for party wall notices. The majority of Victorian and Edwardian terraces in Haringey have shared party walls. You must serve notice on adjoining owners at least two months before starting structural work. If neighbours appoint their own surveyor, the award process can take 2–4 months. Build this into your programme from the start.
• Check for trees before any groundworks. Haringey has significant tree coverage, particularly in Highgate, Muswell Hill, and the grounds around Alexandra Palace. TPOs are common and trees within a conservation area are automatically protected. Any groundworks that might affect tree roots — including foundation excavation — require checking against the council's TPO register and, if necessary, an arboricultural impact assessment.