Loft conversion in Herne Hill

Test the roof space before settling on a layout.

Start with the loft conversion brief

A measured roof survey should establish headroom, structural spans and where a staircase could meet the floor below. Plan the stair, escape route, insulation and building services together before treating the loft as another room.

Compare the proposed roof shape with the address-specific design guidance below. Record chimneys, shared walls and neighbouring rooflines, then ask the appointed designers to identify the structural work and consents the proposal needs.

The local building context

On the west side, Lambeth’s Herne Hill Conservation Area, first designated in December 2007, covers commercial and residential buildings of around 1900 near the road’s junctions with Half Moon Lane and Milkwood Road, in red or yellow stock brick under tile or slate. The 2012 statement finds commercial premises on the ground floor of the vast majority, often with storage or homes above; the one exception is Herne Hill Mansions, a wholly residential mansion block with a mature front garden. It notes that building east of the railway tended to be later, with detached and semi-detached houses in bigger gardens.

Opposite, most of the adjoining properties on the Southwark side fall in the Stradella Road Conservation Area, designated on 26 September 2000, which covers Stradella and Winterbrook Roads and bordering properties on Burbage Road and Half Moon Lane. Its appraisal describes mostly single-family houses with a small number of flats: principally semi-detached, on two floors with attic rooms, in plain red brick laid in Flemish bond, originally roofed mainly in natural Welsh slate, with mostly double-hung timber sash windows. A pocket of post-war houses replaced war-damaged ones in Stradella Road.

SE24 appears on both sides of the line: Southwark’s 1987 direction refers to the Sunray Estate, Herne Hill, London SE24, and Lambeth gives the Peabody Estate on Rosendale Road an SE24 address. Lambeth’s statement splits the road by side, but it does not say every address follows that rule, so do not infer the council from which side of the road a house stands on. A ward name such as Lambeth’s Herne Hill & Loughborough Junction says nothing about conservation areas, and the Dulwich Estate’s Scheme, which reaches Stradella Road and the Sunray Estate, is defined across Southwark, Lambeth and Lewisham, so ask the Estate whether it covers your address. Even Lambeth’s skip licence page tells applicants to check, with GOV.UK’s Find your local council service, that a location really is in Lambeth. Once the council is known, its conservation area map, the statutory list and its Article 4 pages come next, and after them the deeds or lease and earlier consents for the property.

Local design and consent context

Neither appraisal carries an adoption date; the Stradella Road one cites national guidance of March 2010, so it is no older than that. Given an unaltered roofscape, it treats roof extensions and changes to the basic roof form as generally unacceptable, full-width rear extensions as normally unacceptable and side extensions or link blocks that close the gaps between houses as unlikely to be acceptable. Aluminium or uPVC replacements should always be avoided, and further losses of front gardens, walls and planting will be resisted wherever possible. It also records a tree preservation order at 25 Burbage Road.

The Sunray appraisal finds dormers and roof extensions unlikely to be acceptable on the estate’s repetitive roofscape, and two-storey rear extensions or ones not set back from side boundaries unlikely too. As a general guide it expects rear extensions to stay within the line of the flank walls and no deeper than 3.5 metres from the house, while noting that a particular site may justify exceeding some criteria. It prefers secondary glazing behind original windows to replacement double glazing, calls aluminium, uPVC and picture windows without glazing bars unsuitable, and finds front-garden hardstanding out of character.

For a Lambeth address, the Lambeth Local Plan 2021 has been the adopted plan since 22 September 2021, with a replacement now in preparation. Lambeth’s Design Guide, an SPD since 8 August 2023, generally supports dormers on a back roof slope; on a front slope it resists any that are not a feature of the building type or group (Part 4). It also expects most basement schemes to need planning permission (Part 5).

Access and site planning

Check the council before booking anything for the street, since Southwark and Lambeth follow different rules. In Southwark, the skip company applies for the licence at least 7 days before delivery, a scaffolding or hoarding licence is applied for at least 15 working days ahead, and a parking bay suspension needs seven days’ notice. In Lambeth, only the skip company can obtain a skip licence, a highways licence covers scaffolding, hoarding, fencing, gantries and stored materials, and a standard suspension, including one for a skip, needs 10 or more working days’ notice.

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The Herne Hill area guide · Loft conversion across London · Hampstead Architecture & Planning · Hampstead Chartered Surveyors

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