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Slate-clad roof extension on a yellow-brick London terraced house
Photograph: Daniel Sikpi

01Camden, London

Mansard roof drawings for Camden terraces

Camden's Home Improvements guidance describes the mansard it expects: a steep lower slope rising from behind the parapet, with the cornice, parapet and chimney stacks kept. We draw to that description and to your terrace's own roofline, from £845 including VAT.

From £845 (VAT included)

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    02The brief

    The mansard Camden describes

    The Home Improvements CPG (Camden Planning Guidance) says the lower slope, usually 60-70 degrees, should rise from behind the parapet with a substantial set back and a gutter, keeping the cornice, parapet and chimney stacks.

    It then sets a test on the terrace. A new roof level on a complete terrace with no extensions is likely to be acceptable in traditional form, unless the Conservation Area Appraisal identifies the roofline as significant, in which case the guidance treats it as unlikely to be acceptable in any form. We read the appraisal for your street before we draw a line.

    Upper floors of a large yellow-brick Victorian house in London with chimney pots
    Converted loft bedroom with roof windows and a Juliet balcony
    Photograph: Imad Clicks

    03The record

    Local figures for Camden

    Figures with their unit, period and source
    MeasureValuePeriodSource
    The mansard lower slope (usually 60-70 degrees) should rise from behind the parapet with a substantial set back and gutter, keeping the cornice, parapet and chimney stacks.60-70 degreesNo periodcamden.gov.uk, Home Improvements CPG, p.50, section 2.2.2
    Class B, condition B.2(b)(i)(aa)Class B requires the original eaves to be maintained or reinstated, which a parapet-fronted mansard normally removesNo periodlegislation.gov.uk
    Class AA, para AA.1(c)Class AA additional storeys exclude houses built before 1 Jul 1948 or after 28 Oct 2018No periodlegislation.gov.uk
    Class AA, para AA.1(b)Class AA is not available on article 2(3) landNo periodlegislation.gov.uk
    Householder: alterations/extensions to a single dwellinghouse, from 1 Apr 2026548 GBPNo periodribblevalley.gov.uk
    Party Wall etc. Act 1996 s3(2)(a)Party structure notice at least 2 months before workNo periodlegislation.gov.uk
    Conservation areas40 named conservation areas published by the councilNo periodplanning.data.gov.uk
    Article 4 directions21 Article 4 directions published by the councilNo periodplanning.data.gov.uk
    Listed building entries1,971 list entries (Historic England, within the LPA boundary)No periodplanning.data.gov.uk
    Households living in a house13.3 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Householder decisions (PS2)404 decisions2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Householder applications granted (PS2)88.4 % of householder decisions2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk

    A blank value means the figure has not been published, not that there are none. Check your own address with the council.

    Camden6 neighbouring councils
    Councils bordering Camden

    04The streets

    Householder applications by street in Camden

    Streets in Camden with the most householder applications, and the share approved
    StreetApplicationsApproved
    Crediton Hill2291%
    Belsize Lane1994%
    Elliott Square17100%
    Constantine Road16100%
    King Henry's Road1691%
    Camden Mews1490%
    Elsworthy Road1477%
    Solent Road1492%
    Sumatra Road1493%
    Goldhurst Terrace13100%
    Dartmouth Park Road1290%
    Hillfield Road1282%
    Hollycroft Avenue1280%
    Meadowbank1282%
    Patshull Road12100%

    Counts of householder applications by street; no individual applications are shown. Streets with fewer than five applications are left out.

    GLA Planning London Datahub, householder applications

    05The drawing

    A mansard roof in sectionA, Camden: lower slope: 60-70 degrees. B, Permitted development and the eaves: Class B requires the original eaves to be maintained or reinstated, which a parapet-fronted mansard normally removes. C, Additional storeys under permitted development: Class AA additional storeys exclude houses built before 1 Jul 1948 or after 28 Oct 2018. D, Fire protection to the stair: New storey above 4.5 m by loft conversion: protect the full escape route with fire-resisting doors (min E 20) and partitions (min REI 30)ABCD

    A mansard roof in section

    A London terrace with a mansard behind the parapet. The lettered marks show the limits the legend gives.

    A Camden: lower slope
    60-70 degrees
    B Permitted development and the eaves
    Class B requires the original eaves to be maintained or reinstated, which a parapet-fronted mansard normally removes
    C Additional storeys under permitted development
    Class AA additional storeys exclude houses built before 1 Jul 1948 or after 28 Oct 2018
    D Fire protection to the stair
    New storey above 4.5 m by loft conversion: protect the full escape route with fire-resisting doors (min E 20) and partitions (min REI 30)
    The mansard in three dimensions3D
    Scroll the page: the model turns with it.

    06The detail

    Conservation areas, Article 4 and the permitted routes

    Camden publishes 40 conservation areas and 21 Article 4 directions covering 21 areas. Class B rarely fits a mansard: Class B requires the original eaves to be maintained or reinstated, which a parapet-fronted mansard normally removes.

    Class AA is closed to older terraces. Class AA additional storeys exclude houses built before 1 Jul 1948 or after 28 Oct 2018, and Class AA is not available on article 2(3) land. Householder planning permission is the route.

    Roofs shared between flats

    Only 13.3% of Camden households live in a house, so a roof can be shared by several flats. A mansard then depends on the freeholder and the other owners as well as the council.

    Where the work touches a party structure, Party structure notice at least 2 months before work. The survey records each shared wall so the notices can be served on time.

    Householder decisions and fees

    In the four most recent quarterly returns Camden decided 404 householder applications and granted 88.4%. At appeal, 35.5% of the 76 householder appeals decided were allowed. These are past decisions, not a forecast for your roof. Camden's own charge for a householder application is £548, which sits on top of our drawing fee.

    Listed houses and neighbourhood guides

    Camden holds 1,971 list entries, so a roof change can need consent as well. See listed building consent drawings in Camden, and basement conversion drawings in Camden for a lower floor.

    For period terraces in particular streets, start with architectural drawings in Belsize Park or Primrose Hill, and for other councils' roof rules read the mansard roof drawings hub.

    Planning sheet for a single-storey rear extension: proposed ground floor plan and rear elevation, with the Property Architecture title block
    Sample drawing. Proposed plan and rear elevation from a planning application set, sheet 03 at 1:50.

    07The papers

    What the drawings rest on

    Brick cottage with a tiled roof, chimneys and a front dormer windowLawful development certificates
    Photograph: Tanya Barrow
    Loft floor plan marked up in an independent review, with three critical issues clouded and explained
    Sample drawing. A loft plan with the reviewer’s mark-up: stair pitch, dormer cheeks and roof ventilation.

    08Correspondence

    Questions

    Does Camden allow a mansard on any terrace?

    Not automatically. The test turns on the terrace and on the Conservation Area Appraisal for the street, which can mark the roofline as significant.

    What happens to the parapet and chimney stacks?

    Camden's guidance asks for the cornice, parapet and chimney stacks to be kept and for the lower slope to rise from behind the parapet. Our elevations show each one.

    Can I use permitted development for a mansard in Camden?

    Rarely. Class B requires the original eaves to be maintained or reinstated, which a parapet-fronted mansard normally removes, and Class AA is not available on article 2(3) land. We confirm the route in a free constraints check before quoting.

    Rear view of brick terraced houses in London with slate roofs and chimney stacks along the shared roofline

    13.3%

    of households living in a house or bungalow (detached, semi-detached or terraced)

    Households living in a house, Camden, Census 2021. Source: nomisweb.co.uk

    Photograph: Ben Hadfield

    09Further reading

    Other services in Camden

    Mansard roof drawings nearby

    10Sources

    Sources and dates

    Licences

    Kensington street lined with brick townhouses and lit streetlamps beneath an orange dusk sky

    Send us the address of your house.

    We look up the conservation area, listing and Article 4 position, then reply with a fixed fee. A message before 3pm is answered the same working day.

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    Mansard roof drawings in Camden