Builders in Harrow

Kenton, Harrow Weald, Rayners Lane and North Harrow are almost entirely 1930s semis and detached houses with bay fronts, hipped roofs and side passages. Harrow on the Hill is different: Georgian and Victorian houses around the school and the church in one of the borough's most protected conservation areas. Pinner has a medieval High Street conservation area with Tudor and Georgian houses and generous 1930s streets around it. Harrow has 30 conservation areas in all.

Harrow is its own planning authority, the London Borough of Harrow, and publishes a residential design guide that sets out what it expects of extensions: single-storey rear extensions are generally accepted within permitted development or on application; side extensions should be set back and subordinate; two-storey side extensions should keep a gap to the boundary; and rear dormers are acceptable where they sit within the roof slope and below the ridge. On Harrow on the Hill, Pinner High Street and the other conservation areas, Article 4 directions remove permitted development for many changes and applications are judged on the character appraisals. Harrow's householder applications are usually decided within the statutory eight weeks.

Rear kitchen extensions and wraparounds on 1930s semis, often with a hip-to-gable loft in the same contract; double-storey side extensions adding a fourth bedroom; and whole-house renovations of inherited houses. On the Hill and in Pinner village, period-sensitive renovation and rear extensions designed for the conservation area.

Harrow's 1930s streets have driveways and reasonable access; Harrow on the Hill's narrow lanes need deliveries scheduled and scaffold licences arranged with the council. The London clay and many street trees mean deep foundations, and Harrow's building control is consistent about foundation-depth tables. Semis mean party wall notices for most projects.