Region guide · Enfield · Barnet · Haringey

House extensions in North London, borough by borough

Our North London patch runs across five councils: Enfield, Barnet and Haringey, with Camden and Hackney along the southern edge. Each keeps its own conservation areas and its own local rules, and each has its own record of what it approves and refuses.

This page takes them one at a time: what Enfield, Barnet and Haringey decided over the last year, the local rules to check before anything is drawn, and the area guide for every North London town we cover.

Who builds it

Who builds your North London extension

North London projects are designed, managed and built by Pine Grove's own team. The Extension Company is the extensions studio of Pine Grove Design & Build Ltd (company number 13133967, registered in England & Wales), so the company that surveys your house, draws the scheme and takes it through planning is the company on site when it is built.

That counts most on the awkward jobs: a house on a council boundary, a conservation area where the brick and joinery have to match the drawings, or a loft where the planning route shapes the design. One team carries it from the first visit to handover, on one fixed, itemised price.

Enfield Council

Enfield: Southgate, Winchmore Hill and the EN postcodes

Which council decides where

Enfield decides Southgate, Oakwood, Winchmore Hill, Palmers Green, Edmonton, Enfield Town and Hadley Wood. Hadley Wood is the one to watch: it shares the EN4 postcode with East Barnet, but Enfield decides it. Cockfosters is split: Enfield decides the Trent Park side and the streets around the station, and Barnet the avenues further west, around Games Road and Mount Pleasant.

Local rules to check

  • Conservation areas: Southgate Green, Winchmore Hill Green, Grange Park, Bush Hill Park, Enfield Town, Hadley Wood and Trent Park are among them.
  • Article 4 directions: Enfield has directions that remove permitted development rights in several of its conservation areas, including Southgate Green, Winchmore Hill, Grange Park, Bush Hill Park and Hadley Wood. If your house is inside one, check which rights the direction covers before counting on permitted development.
  • Green belt: the north of the borough, Trent Park and Crews Hill included, is green belt. An extension there is judged by its size against the original house.

Enfield Council decisions

Extension and loft applications decided by Enfield Council, 23 September 2025 to 22 September 2026
DecidedApprovedRefused
1,4621,245217
Decided 23 September 2025 to 22 September 2026. Source: GLA Planning London Datahub, pulled 22 September 2026. Householder applications, lawful development certificates and larger-home prior approvals for extensions and lofts; withdrawn and undetermined applications are not counted. Search Enfield's planning register

Barnet Council

Barnet: from Finchley and Hendon out to the green belt

Which council decides where

Barnet decides Barnet itself, East and New Barnet, Arkley, Monken Hadley, Whetstone, Totteridge, the three Finchleys, Friern Barnet, Hendon, Golders Green, Mill Hill, Edgware and Hampstead Garden Suburb. At Edgware the High Street is the line: houses to the west of it go to Harrow. The western fringe of Muswell Hill is Barnet too, although most of Muswell Hill is Haringey.

Local rules to check

  • Hampstead Garden Suburb: two consents, one from the Hampstead Garden Suburb Trust and one from Barnet. The Hampstead Garden Suburb Trust guide explains how the two run side by side.
  • Conservation areas: Monken Hadley, Totteridge, Mill Hill, Wood Street, Finchley Church End, Finchley Garden Village, Moss Hall Crescent, Golders Green, Hendon Church End and Hendon The Burroughs are among them.
  • Article 4 directions: parts of Monken Hadley, Totteridge, Mill Hill, Wood Street, Finchley Church End, Finchley Garden Village, Moss Hall Crescent, Hendon The Burroughs and Hampstead Garden Suburb are covered. Each of these lists the right to enlarge the house (Part 1, Class A) among the rights it takes away, so check the direction for your address before relying on permitted development.
  • Green belt: it wraps around Arkley, Totteridge and the Mill Hill ridge, where the same test of proportion to the original house applies.

Barnet Council decisions

Extension and loft applications decided by Barnet Council, 23 September 2025 to 22 September 2026
DecidedApprovedRefused
1,7501,335415
Decided 23 September 2025 to 22 September 2026. Source: GLA Planning London Datahub, pulled 22 September 2026. Householder applications, lawful development certificates and larger-home prior approvals for extensions and lofts; withdrawn and undetermined applications are not counted. Search Barnet's planning register

Haringey Council

Haringey: Muswell Hill, Highgate, Crouch End and Tottenham

Which council decides where

Haringey decides Muswell Hill, Highgate, Crouch End, Hornsey, Wood Green and Tottenham. Two edges need checking. The west side of Highgate village falls to Camden, and the western fringe of Muswell Hill to Barnet.

Local rules to check

  • Conservation areas: Muswell Hill, Fortis Green, Rookfield, Highgate, Crouch End, Stroud Green, Hornsey High Street, Noel Park, Wood Green Common and Bruce Castle are among them.
  • Article 4 directions: the only Haringey directions planning.data.gov.uk maps are on employment land, so check the council's own Article 4 list for your street before relying on permitted development.
  • Inside a conservation area: the national limits still bite. Side extensions and roof enlargements such as dormers fall outside permitted development, so a side return or a loft dormer on a conservation area terrace needs a planning application.

Haringey Council decisions

Extension and loft applications decided by Haringey Council, 23 September 2025 to 22 September 2026
DecidedApprovedRefused
71064367
Decided 23 September 2025 to 22 September 2026. Source: GLA Planning London Datahub, pulled 22 September 2026. Householder applications, lawful development certificates and larger-home prior approvals for extensions and lofts; withdrawn and undetermined applications are not counted. Search Haringey's planning register

The southern edge

The Camden and Hackney edges

North London's southern edge crosses into two more councils, each with rules of its own.

Camden: Hampstead and the west side of Highgate

Hampstead (NW3) and the west side of Highgate village are decided by Camden. Camden's Article 4 direction on basements, confirmed on 3 October 2016, restricts basement extensions under permitted development, and planning.data.gov.uk maps it across the whole borough. The Hampstead conservation area carries further Article 4 directions on particular houses, and Highgate Village, Holly Lodge Estate, South Hill Park and Redington Frognal are conservation areas too.

Hackney: Stoke Newington

Stoke Newington (N16) is decided by Hackney. The Stoke Newington, Clissold Park, Northwold & Cazenove and Lordship Park conservation areas all sit in and around N16. planning.data.gov.uk has no Article 4 data for Hackney, so check the council's own list before relying on permitted development.

Camden area guides

Hackney area guides

There is no decision table for Camden or Hackney. The datahub's Camden feed carried no lawful development certificates in this window, so a Camden table would not compare like for like with the boroughs above; Hackney is here for Stoke Newington only, so its figures are kept ward by ward rather than as a borough total.

The Hertfordshire border

For houses over the border in Hertfordshire, see the full list of areas.

Local knowledge

What North London houses take

Two kinds of house come up again and again in North London, and they want different things.

The 1930s semi. Oakwood, Cockfosters and large parts of Southgate, Winchmore Hill, Edgware, Mill Hill and outer Barnet were built out between the wars: bay-fronted semis with hipped roofs, a side passage or garage, and long gardens. The usual moves are a hip-to-gable loft with a rear dormer, a two-storey side extension along the old garage line, and a full-width kitchen extension across the back. Outside conservation areas the loft and the rear extension can often go through permitted development or a lawful development certificate. A two-storey side extension always needs planning permission.

The Victorian and Edwardian terrace. Muswell Hill, Crouch End, Hornsey, Wood Green, Palmers Green and Stoke Newington are mostly terraces and tall semis from before the First World War, with a narrow passage beside the back addition. Here the ground floor opens up with a side return extension or a wrap-around, and the loft goes into an L-shaped dormer over the main roof and the back addition.

The protected streets. The historic cores of Monken Hadley, Totteridge, Highgate and Hampstead are conservation areas, where the shortcuts fall away and design quality decides the application. The conservation area guide covers what changes. Hampstead Garden Suburb adds the Trust's own consent on top of Barnet's. And on the green belt around Arkley, Totteridge and Trent Park, extending in the green belt comes down to proportion against the original house.

Not sure which council, or which route?

A free site visit settles both for your house: who decides it, what applies on your street, and whether permitted development, a certificate or a full application suits the scheme.

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What we build

What we build across North London

Whatever the house, the brief usually comes down to one of five things. Kitchen extensions in North London open the back of the house to the garden, most often as a single-storey rear extension. On terraces, a side return extension fills the passage beside the back addition. A double-storey extension adds bedrooms and a bigger kitchen in one build. And loft conversions add a floor without touching the garden; the towns below each have a local loft guide.

Costs

What extensions cost in North London

The price turns on size, structure and finish, so this page does not put one figure on it. Our guide to what extensions cost in North London sets out costs by extension type, by size and by area, and a free site visit turns that into a fixed, itemised quote for your house.

Across London

Beyond North London

North London comes first, but we take on projects across London. Every area we cover has its own guide, from Walthamstow and Chingford in the east to Richmond and Wimbledon Village in the south-west.

Questions, answered

North London extension FAQs

Which council decides my extension?

The one whose boundary your house sits inside, which is not always the one your postcode suggests. Hadley Wood is EN4 but decided by Enfield. In Cockfosters the avenues west of the station, around Games Road and Mount Pleasant, are Barnet's, the west side of Highgate village is Camden, and in Edgware the houses west of the High Street are Harrow. The council for your exact address is confirmed before anything is drawn.

Do I need planning permission for a rear extension?

Not always. Outside conservation areas and Article 4 areas, a single-storey rear extension of up to 3m on an attached house, or 4m on a detached one, is usually permitted development, and the larger-home prior approval route stretches that to 6m and 8m. In a conservation area the larger-home route does not apply, and where an Article 4 direction removes the right to extend, even a modest rear extension needs a planning application.

Is a lawful development certificate worth getting?

Yes, when the work is permitted development. The certificate is the council's written confirmation that the scheme is lawful, and a buyer's solicitor will usually ask for it when you sell. Our decision tables count certificates alongside planning applications and prior approvals, because that is how many loft and rear extension schemes get approved.

Who builds North London projects?

Pine Grove's own team. The Extension Company is the extensions studio of Pine Grove Design & Build Ltd, so the company that draws your scheme and handles the planning is the company that builds it.

Where do the decision figures come from?

From the GLA Planning London Datahub, which gathers planning decisions from London's councils. We count householder applications, lawful development certificates for proposed works and prior approvals for larger home extensions whose description mentions an extension, loft, dormer, hip to gable, mansard, basement, wraparound, side return or infill. Withdrawn and undetermined applications are left out. Every application counts on its own, so a scheme refused and then approved after changes appears in both columns when both decisions fall inside the window. The datahub can lag a council's own register by a few weeks, so each table links to the council register too.

How long does a householder application take?

The council's target for a householder application is eight weeks from the date it is validated. Most of the time goes into preparation before that: the survey, the drawings and, in a conservation area, a heritage statement.

What clients say

Rated 5.0 on Google

5.0 from 16 Google reviews
The Extension Company built a 5m single storey rear extension on our Victorian terrace in Crouch End. Went down the permitted development route so no planning application needed, which they explained up front and saved us months. Kitchen-diner now opens onto the garden with sliding doors. £87k all in, matched the quote.
Harry PopeSingle-storey rear extension, Crouch End · Google review
From the initial site visit onwards to my property in Barnet, we felt that the team actually listened to what we wanted. They suggested a few changes to the layout that we hadn't considered, and those changes have made a huge difference. Would definitely use again and recommend
Ceri JenkinsBarnet · Google review
Used The Extension Company for a loft conversion on our semi detached in Barnet and couldn't be happier. They explained what was possible at the first visit, sorted the planning side, and gave a fixed price with no surprises at the end.…” read the full review
Billie CampbellLoft conversion, Barnet · Google review
We spoke to a few companies before deciding to go with The Extension Company and they just seemed the easiest to deal with. No pushy sales, just honest advice. They kept us updated and the whole process was a lot less stressful than we expected
Annabelle CorpuzGoogle review
Really impressed with the entire project. The side extension and conservatory have been finished to a very high standard and the team made the process straight forward and stress-free. It’s transformed the space and added so much value, would definitely recommend.
ARASide extension & conservatory · Google review
Brilliant experience with the extension company, transparent from the word go. Completed a double story extension for me and I couldn’t be more pleased. Thank you
Sarah JDouble-storey extension · Google review
Couldn't be happier with our loft conversion. We were expecting the build to be stressful, but it was actually a lot easier than we'd imagined. The lads were friendly, worked hard, and the quality of the finish is spot on.…” read the full review
VergeLoft conversion · Google review
I got the extension company to do a bathroom refurb for us a January they done a great job they managed to fit in a large shower as well as a bath
BezBathroom refurbishment · Google review

Reviews shown word for word from our Google profile. Read all 16 reviews on Google

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