Basement conversion in Surbiton

Investigate the structure and ground before design.

Start with the basement conversion brief

Distinguish an existing cellar conversion from excavation for a new basement. Record levels, drainage, access and the adjoining structures, and obtain project-specific ground and structural investigations before relying on a design or budget.

Plan temporary works, waterproofing, ventilation, escape and spoil removal as part of the same brief. Ask Hampstead Chartered Surveyors to assess party-wall matters and Hampstead Architecture & Planning to coordinate the design requirements. An area name alone does not establish ground conditions.

The local building context

Southborough Conservation Area was designated in January 1979 and extended in January 1989 and September 1991, according to the council’s page, and extended again in 2009 under the appraisal the Executive adopted that May. The council sums it up as large detached houses of the 1860s to 1930s around Southborough House, a Grade II building of 1808 by John Nash. The appraisal finds mainly detached houses on generous, well-treed plots, the larger ones mostly on Ashcombe Avenue, Corkran Road, Langley Avenue and Southborough Close, in red and yellow brick under natural red clay tiles.

Thomas Pooley conceived Surbiton’s New Town, and building began in 1838 around the landscaped Claremont Crescent Gardens. The Claremont Road area keeps stuccoed Regency-style semi-detached villas and terraces, with original examples on the north side of Victoria Road and the east sides of Claremont Road and St Philip’s Road, while Claremont Gardens has red-brick houses of 1890. St Andrew’s Square, a later phase, has three-storey Gothic brick terraces of 1876 to 1884, and the Cadogan Road area runs from short terraces in Cleveland Road to large Italianate villas on Cadogan Road and Grove Road.

The Victoria Avenue area, farmland until the early 1890s, has cohesive groups of two-storey red-brick houses built between 1893 and 1904. Surbiton Hill Park was built from 1864 to 1887 as a middle-class estate, its earliest houses Italianate. Oakhill follows the old turnpike of Ewell Road, with stock-brick terraces and villas with stucco dressings, and since 2009 has included 15–25 Langley Road, large houses of three storeys and semi-basement moved out of Southborough. Christchurch, in Berrylands, has houses of the 1860s to the 1880s around the Grade II Christ Church.

Local design and consent context

The council’s pages date the areas as follows: St Andrew’s Square, March 1971, extended October 1987 and June 1991; Southborough, January 1979, extended January 1989 and September 1991; Claremont Road, October 1987, extended July 1991; Surbiton Hill Park, January 1988; Oakhill, April 1988, extended September 2009; Victoria Avenue, July 1988, extended June 1991; Christchurch, September 1988; Cadogan Road, May 1989; Surbiton Town Centre, June 1991; Riverside South, February 2003; and Fishponds Park, November 2004. Southborough’s boundary also changed in 2009, when the Executive adopted the boundary its appraisal recommended and 15–25 Langley Road passed to Oakhill.

Southborough has an appraisal of May 2009, which the Executive adopted on 19 May 2009. Surbiton Town Centre has only a draft appraisal, of January 2008, which is not adopted policy. Riverside South’s linked appraisal is the 2002 study of Portsmouth Road and Queen’s Promenade, written before the area was designated; the area follows the Portsmouth Road and Queen’s Promenade riverside and reaches the Kingston end of Portsmouth Road, so not all of it is Surbiton. The Surbiton advisory committee covers all eleven areas.

Four documents make up the borough’s adopted Development Plan: the London Plan, the Core Strategy (adopted 17 April 2012), the Kingston Town Centre Area Action Plan (2008) and the South London Waste Plan (2022). In the Core Strategy, Policy DM 12 allows alterations that preserve or enhance a heritage asset’s established character, DM 10 names building line, set-back and front boundary among the elements to respect, and DM4 sets the flood-risk policy. Supplementary guidance comes from the Residential Design SPD of 9 July 2013 and the Conservation Area General Guidance adopted in June 2023, which the council weighs as a material consideration when it assesses applications.

Access and site planning

Settle the street arrangements before a start date is fixed. Skips on the public highway are licensed only to skip companies; on private land no licence is needed, and a licensed skip has to be kept at least 15 metres from any junction, bend or road hazard. Only scaffold companies holding the public liability insurance the council requires can apply for a highway scaffold licence, and the scaffold must leave a 1.2-metre route for pedestrians. Hoardings need a licence even on private property, as do materials stored on the highway. Bay suspensions are charged by the day for each five-metre space, and the suspended spaces can lie up to 75 metres from the address; red routes are managed by TfL.

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The Surbiton area guide · Basement conversion across London · Hampstead Architecture & Planning · Hampstead Chartered Surveyors

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