Basement conversion in Arkley

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

Planning data places Arkley Windmill, Arkley War Memorial and the mapped points of many Arkley tree preservation orders in the London Borough of Barnet and its High Barnet ward. Arkley sits on the county boundary with Hertsmere, in Hertfordshire. In 1959 it lay in the Urban District of Barnet, then part of Hertfordshire, and a boundary order made in 1992 moved land both ways from 1 April 1993: its explanatory note says part of Arkley Lane went to Hertsmere, while housing development north-west of Whalebone Park came into Barnet.

Historic England’s list, as planning data records it, includes Arkley Windmill at Grade II*, list entry 1359022, the barn in its grounds at Grade II, Arkley War Memorial at Grade II and the Grade II Church of St Peter, mapped beside the memorial. Elm Farmhouse and adjoining barn, Grade II, is mapped near Galley Lane, and Trinders Lodge and Hyver Hall, both Grade II, are mapped elsewhere in High Barnet ward, inside the Green Belt record. Listing is recorded entry by entry, so read the entry for the exact building.

Barnet’s tree preservation orders name many roads in and around Arkley. Two group orders made in October 2022 cover trees on Barnet Road with Arkley View, Arkley Lane and Arkley Drive, and on Barnet Road with Hedgerow Lane, Hazel Mead and Quinta Drive. Area orders cover land north of Barnet Road around Brickfield Lane and Rowley Lane, from 1976, and the south side of Barnet Road, from 1974. A 2011 order protects trees on the Galley Lane roadside verge, and Barnet now records orders that Hertsmere first made, of 1976 in Kings Road and 1986 in Grimsdyke Crescent.

Local design and consent context

Planning data lists 16 conservation areas in Barnet, among them Totteridge, Mill Hill, Monken Hadley and Wood Street; none is named Arkley or Barnet Gate, and none is mapped at the points of Arkley Windmill, Arkley War Memorial, the Church of St Peter or the many Arkley-area tree orders we checked. That does not rule out every Arkley address, so check the map for the property itself.

Barnet’s Wood Street Conservation Area Character Appraisal Statement, adopted in July 2007, describes that area running east to west from the top of Barnet Hill along the ridge towards Arkley and including Wood Street itself westward as far as The Whalebones; it was designated in 1969 and extended in 1979. The appraisal notes that the historic county boundary runs through this part of the borough, with Wood Street a peninsula of Hertfordshire cutting eastward into Middlesex. Wood Street is a neighbouring designation, not an Arkley one.

Barnet has 15 Article 4 directions on planning data. Apart from two, each is for a named conservation area, none of them Arkley, and none of those is mapped at the points of Arkley’s listed landmarks or of the many Arkley-area tree orders we checked. Barnet’s direction on small houses in multiple occupation, in planning data from 29 May 2016, does cover those points, but it withdraws only the permitted development right in Part 3 Class L, for changes between a house and a small house in multiple occupation, and does not concern building works.

Access and site planning

For a Barnet address, the council’s published construction working hours say noisy work should only be carried out Monday to Friday, 8am to 6pm, and Saturday, 8am to 1pm, and at no time on a Sunday or bank holiday. If the council lookup shows a Hertsmere address, ask Hertsmere which hours apply. In a flat, ask the landlord or managing agent about any building rules on noise, deliveries and shared parts. If you will live at home through the work, decide which rooms stay usable and when water or power will be off, and tell neighbours what is planned and when.

Continue planning

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

Discuss your project

Tell us what you are planning in Arkley

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.