Basement conversion in Stamford Brook

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

According to Hounslow’s appraisal, in 1898 the architect and surveyor J A Gill Knight took a lease of about 12 acres south of the common to build mansion flats and semi-detached houses for comfortably-off middle-class families and tenants. After the two listed houses came the mansion blocks of 1901 to 1905 and then the houses of 1907 to 1933. Stamford Brook station did not open until 1912, the appraisal adds, so building was not finished until after the First World War, and the railway and station border the conservation area to the south.

Street by street, the appraisal is specific. On Pleydell Avenue the houses on the western side are larger, with prominent decorative gables, decorative roof tiles and original windows. Vaughan Avenue’s houses vary considerably in design and rise to three storeys at the eastern end. Prebend Gardens has two-storey terraces of four houses on its western side and mostly two-storey semis on the eastern. West of the Pleydell Avenue junction, the houses of Stamford Brook Common South Side have prominent half-timbered gables and decorated timber porches, each built of brick with a rendered first floor.

The appraisal credits the area’s elegant Edwardian character to the relationship between the common, the listed buildings, the mansion blocks and the family housing, and says scale and character have survived because the buildings have not had obtrusive extensions, alterations have been kept to a minimum and most front gardens remain. Among the further protections it lists are registration as Common Land and Local Open Space status, and it names Stamford Brook Common as a designated Local Open Space.

Hounslow: Stamford Brook Conservation Area Appraisal, adopted January 2021

Local design and consent context

Hounslow designated the Stamford Brook Conservation Area on 13 January 1998, and its appraisal, consulted on in autumn 2019 and adopted by the council in January 2021, says the area had not been altered or extended since. The appraisal places it in the north-east part of Chiswick and explains that its eastern boundary is irregular because it partly follows an old ditch along the former parish boundary between Chiswick and Hammersmith. To the east lies Hammersmith and Fulham’s Ravenscourt and Starch Green Conservation Area.

On the Hammersmith and Fulham side, the council’s summary of Ravenscourt and Starch Green Direction No. 1 lists 2–10 (even), 5 and 7, and 9–25 (odd) Stamford Brook Road for alterations to the front roof, gables and dormers, coverings included, changes to rear roof coverings and the painting of unpainted brickwork. Direction No. 4 lists 2–10 (even) and 9–25 (odd) for alterations to the front elevation. Both summaries describe themselves as outside the legal documentation, so it is the wording of each direction that governs. Hammersmith and Fulham also has a borough-wide basement direction, in force from 26 April 2018.

Hammersmith and Fulham adopted its current Local Plan on 28 February 2018, and that plan is the basis for planning decisions at its Stamford Brook Road addresses. Its Policy DC4 expects an extension to be subservient and never to dominate the parent building, and Policy DC11 stops a basement reaching under more than half the depth of the garden. A Regulation 18 draft of a replacement plan has been out to consultation, but it remains an emerging document, not adopted policy.

Access and site planning

Check which council manages the street before booking a skip or scaffold. In Hounslow, licences from Hounslow Highways are needed for scaffolding, hoarding, building materials, crane operations and skips, and a parking suspension must be applied for at least ten working days before the space is needed. On the Hammersmith and Fulham side, the skip firm, not the householder, applies for the skip licence, with 14 days as the shortest period; the scaffolding firm applies for the scaffold licence, which lasts at least a month; and parking bays can be suspended, up to six of them for up to three days, on eight days’ notice, counting Saturdays and Sundays.

Continue planning

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

Discuss your project

Tell us what you are planning in Stamford Brook

Share the property location, the work you have in mind and any drawings or permissions you already have.

£5M public liability, £10M employers’ liability and contractors’ all risks cover.

Design support: Hampstead Architecture & Planning.
Surveying support: Hampstead Chartered Surveyors.