Builders in Harrow

Harrow is classic Metro-land. Apart from historic centres such as Harrow on the Hill, Pinner village and Stanmore, most of the borough was built up between the wars along the railway lines, with estates of semi-detached and detached houses at Rayners Lane, North Harrow, Hatch End, Kenton, Harrow Weald and Stanmore.

That shows in the 2021 Census: 65% of Harrow's 89,600 households lived in a house, a higher share than in Brent, Barnet or Ealing. 37% lived in semi-detached houses, 17% in terraced houses and 11% in detached houses, while a third lived in flats.

Because so many houses share the same interwar designs, the same improvements come up again and again: hip-to-gable loft conversions with rear dormers, single-storey rear kitchen extensions, two-storey side extensions over the old garage, and refurbishments that open up the ground floor. The details still vary from street to street, especially in the borough's conservation areas.

Harrow Council judges householder applications against its Residential Design Guide SPD (2010), which includes Harrow's long-standing 45-degree code for protecting neighbours' windows. Its preferred loft conversion for semi-detached and terraced houses is a hip-to-gable with a rear dormer, and it says there is generally no scope for first-floor or two-storey rear extensions on mid-terraced houses. We summarise the detail on our Harrow loft conversions and Harrow extensions pages.

Harrow has 30 conservation areas, grouped into Harrow on the Hill, Pinner, Stanmore and Edgware, and Harrow Weald. Each group has its own supplementary planning document with appraisals, management strategies and maps showing any Article 4 directions, published on the council's conservation pages. Open land in the north of the borough is Green Belt, where extensions face stricter limits.