Basement conversion in Finchley

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

Barnet’s appraisal of the Finchley Church End Conservation Area, dated 31 August 2011, describes Edwardian shopping parades at the junction of Regents Park Road and Hendon Lane and modest Victorian cottages on Gravel Hill, Hendon Lane and College Terrace, where terraces such as College Terrace have slate roofs, canted bays, recessed doorways and white-painted sashes. It also records two Italianate villas in stucco and slate, Avenue House of 1859 and Hertford Lodge, which was restored and converted to apartments after a fire, and modern flats and small houses at Rectory Close and Spencer Close.

Finchley Garden Village, centred on Village Road, is described in its 2013 appraisal as entirely residential, with 51 properties on about 3.6 hectares. Frank E. Stratton was the principal architect, the first 13 houses were occupied by the end of 1909 and the rest were completed by 1914, apart from Nos. 39 and 40. The houses are in the Arts and Crafts style, mostly roughcast render under tiled roofs, with front gables, leaded-light timber casements and hooded entrance canopies, generally behind picket fences, and the appraisal notes that many have lost their original leaded lights.

In North Finchley, the twelve Victorian villas of Moss Hall Crescent stand south of Tally Ho Corner on the western side of Ballards Lane: five semi-detached pairs and a detached house at each end, in cream stock brick under shallow slate roofs. Their 2015 appraisal found most converted into flats, with only Nos. 7 and 12 still single houses. Glenhill Close, due south of Finchley Central station, is described in its appraisal statement as 66 flats built in 1936 and from 1961, the 1936 blocks with steep concrete-tiled roofs and curved Crittall steel suntrap windows.

Local design and consent context

Barnet’s conservation areas in and around Finchley include Moss Hall Crescent, designated on 19 July 1974; Finchley Garden Village, on 22 November 1978; Finchley Church End, in 1979; and Glenhill Close, on 27 March 2001. Barnet’s open data calls its appraisals and boundary maps the authoritative source, so read the map for the address.

The character appraisals are dated 31 August 2011 for Finchley Church End, 26 September 2013 for Finchley Garden Village (after a 21-day consultation in July 2013, with Design Guidance of the same date) and 26 August 2015 for Moss Hall Crescent; Glenhill Close has an undated appraisal statement. Each describes its area as it was then, and the Finchley Church End boundary map was last amended on 31 August 2011.

Barnet publishes the legal orders for its Article 4 directions as open data. In Finchley Church End, the 2011 direction, sealed on 30 September 2011, applies only to the properties it names: 9 and 10 College Terrace; 1 to 4 Park Cottages, Morningside Cottage and 28 Hendon Lane; 1 and 2 Hendon Avenue; and Flora and Gothic Cottages on Gravel Hill. It controls listed classes of work that would front a highway, waterway or open space, such as enlarging or altering a house, and, without that frontage limit, the erection, alteration or removal of a chimney.

Access and site planning

Barnet’s published construction working hours for noisy work are Monday to Friday, 8am to 6pm, and Saturday, 8am to 1pm, with none on a Sunday or bank holiday. A lease or building manager may set tighter rules on noise, deliveries and shared parts. If you will live at home during the work, decide which rooms stay usable, give notice before water or power is switched off, and tell neighbours, including anyone sharing the stairs or front garden, what is planned and when.

Continue planning

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

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