House extension in Hatch End

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

Harrow’s 2021 character study counts the Victorian semi-detached villas at Woodridings among Hatch End’s oldest development, and the 2011 assessment says initial suburban development there was dominated by Woodridings, an estate of Italianate villas along Uxbridge Road, Devonshire Road and Wellington Road. Around Wellington, Devonshire and Cornwall Roads it records a mix: one three-storey Italianate pair surviving on Wellington Road, Edwardian and inter-war detached houses, a 1930s mansion block, 1960s and 1970s flats and 1950s maisonettes in two-storey pairs, with some front gardens lost to hard surfacing and forecourt parking.

Inter-war growth brought the garden suburb of Pinnerwood Park, the Tudorbethan estate at Sherrington Avenue and Royston Park. Around The Avenue, Royston Park Road and Royston Grove, the 2011 assessment records mainly Edwardian, 1930s and post-war houses, usually two storeys plus rooms in the roof, many Arts and Crafts in style with tall chimneys and complex hipped and gabled roofs in brick, tile and render, set well back on wide streets with very large mature trees. Along Uxbridge Road it records mainly 1930s detached and some semi-detached houses, some with Tudorbethan bays and gables.

The name Hatch End and an HA5 postcode do not settle the council, a conservation area boundary, a listing, Article 4 coverage or the consent route. The station was originally named Pinner and kept a Pinner reference until 1956, an official Hatch End address can still read Pinner, HA5, and Hatch End ward includes an HA3 address on Headstone Lane. Another council’s area lies not far beyond the northern edge, so confirm the council for the address, then check Harrow’s conservation area pages and Article 4 schedules, the listing and local list entries, the title or lease and the planning history.

Local design and consent context

Harrow designated Pinnerwood Park Estate as a conservation area on 31 August 1989. Its current appraisal and management strategy, adopted in December 2009 as Appendix 8 to the Pinner Conservation Areas SPD, replaced a February 1990 appraisal and carries weight as a material planning consideration. Harrow lists the area on its Pinner page, its 2021 character study names it among Hatch End’s garden suburb estates, and the Pinner SPD says the Hatch End local centre lies outside the conservation area but forms part of its setting.

The conservation area is in two parts, and the appraisal lists its roads, several only in part, among them Uxbridge Road, Grimsdyke Road, Altham Road, Woodhall Drive and Pinner Hill Road, so check the house number as well as the street. It records hipped roofs turned into gables, large dormers and third front gables as eroding the area’s appearance, says new front dormers would be out of character and hip-to-gable conversion is unlikely to be permitted, finds conservation rooflights only likely to be acceptable at the rear, and asks extensions not to overpower the house or offset the symmetry of paired houses.

To its north, on the borough boundary with Hertfordshire, Pinnerwood Farm is a separate conservation area; its 2009 appraisal records it as first designated in 1980, with its boundary unchanged since, and characterised by very low-density housing in spacious gardens.

Access and site planning

Plan deliveries, waste and protection for any shared hall or drive before work starts. In Harrow, a skip on the public highway needs a licence, obtained by the skip company, and must be lit in the dark; scaffolding on the highway needs a licence issued to the scaffolding company; and building materials on the highway need a licence even briefly, placed on the carriageway rather than the footway. Bay suspensions are granted only in marked bays and can take up to 10 working days. Harrow’s 2011 assessment describes Uxbridge Road as heavily trafficked; check whether the road outside is one of TfL’s red routes, where TfL issues the highway licences for skips, scaffolds and building materials.

Continue planning

The Hatch End area guide · House extension across London · Hampstead Architecture & Planning · Hampstead Chartered Surveyors

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