House extension in Grange Park

Connect the added space to the existing home.

Start with the house extension brief

Begin with how the new space will meet the old rooms, garden and circulation. A measured brief should record boundaries, levels, existing drains, neighbouring windows and the parts of the building you intend to keep.

Develop daylight, structure and services alongside the floor plan. Agree which openings and finishes are included, how the existing home will be protected during construction and which decisions need surveys or approval before a quotation.

The local building context

The appraisal, approved in June 2015, places the conservation area south-west of Enfield Town, midway between the town and Winchmore Hill, in the valley between the railway embankment and Bush Hill, with golf courses and open space along both long sides. The estate took its name from Old Park Grange, or Pike’s Farm, demolished in 1913. The builder Richard Metherall, who had built in Muswell Hill, bought the land, and Grange Park station was built in return for his deal with the railway company: an exchange of land and an agreement to build a certain number of houses for commuters.

In the conservation area, houses are closely built and, except at the northern end of The Chine, stand on narrow plots; towards its top, nos. 99–127 (odd) and 90–98 (even) are substantial detached houses on more spacious plots. In the southern part of The Chine, windows are sashes, or casements in horizontal ranges with stone mullions, sometimes with leaded lights. The appraisal finds the houses’ character largely intact apart from uPVC replacement windows, mostly fitted before designation, and records front gardens paved for parking and walls, fences and hedges lost, with Old Park Ridings suffering particularly.

Neither the name Grange Park nor an N21 postcode tells you which council decides, whether a home is inside the conservation area, whether the Article 4 direction covers it, whether a building is listed or locally listed, or which consent route the work takes. The Grange Park ward also takes in EN1 and EN2 addresses, and the direction covers only scheduled house numbers. Confirm the council with the official lookup, then read Enfield’s conservation area documents, the Article 4 schedule and map, the Local Heritage List, the title or lease and the planning history of the property itself.

Local design and consent context

Planning Data records the Grange Park Conservation Area, reference CA19, as a London Borough of Enfield conservation area, and the appraisal says it was designated on 5 November 2008 and that its boundary has remained unchanged. Enfield, which has 22 conservation areas, links four documents for it: the character appraisal, the management proposals, the 2008 Article 4 directions, which also cover the Meadway and The Crescent conservation areas, and an Article 4 map.

The management proposals name side and rear extensions as the main pressure and say the Article 4 direction lets the council manage their size, form and materials. They add that the council will resist the loss of traditional details such as windows, doors, chimneys, decorative external timber, plasterwork, brickwork and boundary walls; uPVC and concrete roof tiles will not normally be appropriate; new front-garden parking will be resisted; and side extensions should not obscure the views of trees between houses. Any application affecting a property in the conservation area should include a Heritage Statement.

For house projects, DMD 11 says a single-storey rear extension should not exceed 3 metres beyond the original rear wall of a terraced or semi-detached house, or 4 metres for a detached one; DMD 13 generally permits front roof dormers only where they do not materially affect the character of the area; and DMD 14 asks side extensions to keep at least 1 metre from the boundary. The adopted Policies Map shades the open land along both long sides of the conservation area as Metropolitan Open Land, which the Development Management Document gives the same protection and status as the Green Belt.

Access and site planning

The two long roads rise steeply from The Grangeway and most front gardens are shallow, so plan where deliveries stop and waste waits. To place a skip on the road, the skip company must register with Enfield and hold a licence for that specific site, valid for 14 days unless extended. Scaffolding or hoarding on a road or pavement needs a licence, processed within 5 working days and valid for 30 days, and if Enfield decides the road should be closed, the temporary traffic order needs at least six weeks’ notice. For building works Enfield offers a temporary parking dispensation, though it does not reserve a space.

Continue planning

The Grange Park area guide · House extension across London · Hampstead Architecture & Planning · Hampstead Chartered Surveyors

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