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Tower Hamlets, London

L-shaped dormer drawings in Tower Hamlets

Much of Tower Hamlets is flats, so a house with a roof to extend is rare, and the borough has many designations around the ones that remain. We draw L-shaped dormers in Tower Hamlets as MCIAT chartered architectural technologists, and each job starts with the conservation areas and Article 4 directions that cover your street.

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  • LABC Partnered
  • Fixed fees, VAT included

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    Architectural model of a four-storey London stucco townhouse in its terrace, with a portico, area railings, sash windows, a cornice and chimney stacks
    The house as it stands: four storeys over a lower ground floor.Existing Proposed worksAn illustrative model, built for this page.

    How we work on l-shaped dormer drawings

    Nine steps from first call to approval.

    The same model cut through the middle: every floor, the stair, the chimney breasts, the new mansard, rear extension and basement in section
    Section through the model: every floor on one datum.

    1. Enquiry and constraints check

      We check the property against conservation areas, listed status, Article 4 directions, tree preservation orders, flood zone and planning history. We choose the right route and send a fixed quote.

    2. Measured survey

      We survey the house on one datum: rooms, levels, boundaries, drains, trees and the neighbours' windows that the 45° and 25° tests depend on.

    3. Design options

      We model the house in Revit and show you options in 3D and plan, with the planning strategy and the precedents in your street.

    4. Design frozen

      You choose an option in writing. Nothing changes after this without your say.

    5. Independent check

      A second chartered technologist checks every sheet against the council's validation checklist and the policy. A senior review signs it off before anything is submitted.

    6. Submission

      We prepare the forms, certificates, fee and documents and submit through the Planning Portal.

    7. Officer liaison

      We answer the planning officer and make any amendments within five working days, at no charge until approval.

    8. Building regulations

      Technical drawings are coordinated with the structural engineer's calculations, the drainage and the planning conditions.

    9. Approval and hand-over

      Building control approval, then a next-steps pack covering the commencement notice, party wall timing and CIL.

    Free redraws until approval. Every drawing set is checked independently, and the checker is never the person who drew it.

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    Brick cottage with a tiled roof, chimneys and a front dormer window

    Where an L-shaped dormer fits in Tower Hamlets

    The borough's plan is the Tower Hamlets Local Plan 2031: Managing Growth and Sharing the Benefits, adopted in 2,020. Its supplementary guidance leans towards density: the Central Area Good Growth SPD and the High Density Living SPD concern large schemes, and neither is a householder document, so an officer reading a dormer application leans on the plan's design policies and on the character of the street.

    The houses that suit an L are the terraces of Bethnal Green, Bow, Stepney and Limehouse, many of them with a rear addition. Land is scarce here: domestic gardens cover only 7.4 per cent of the borough, so the roof is often the only place left to grow.

    If the permitted route is open, the roof volume ceiling is 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume. On a Tower Hamlets terrace with a deep outrigger the L can reach that quickly, which is why we model it before showing you options.

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

    Local figures for Tower Hamlets

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Conservation areas59 named conservation areas published by the council—planning.data.gov.uk
    Article 4 directions64 Article 4 directions published by the council—planning.data.gov.uk
    Article 4 direction areas63 Article 4 direction area polygons published by the council—planning.data.gov.uk
    Listed building entries916 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    worldHeritageSites2 World Heritage Sites intersecting the LPA boundary—planning.data.gov.uk
    Householder decisions191 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted92.7 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time95.8 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Domestic gardens share of land (GLUD 2005)7.4 % of land that is domestic garden (GLUD 2005)2005data.london.gov.uk
    GPDO 2015 Sch 2 Pt 1 Class B, para B.1(d)40 m³ (terrace house) / 50 m³ (any other house) additional roof volume—legislation.gov.uk

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

    Councils bordering Tower Hamlets
    Loft enlargement in section: the permitted development limitsExtra roof volume allowed: 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume. Set-back from the eaves: Original eaves maintained; enlargement set at least 0.2 m from the eaves measured up the roof slope, so far as practicable (not required for hip-to-gable or roofs joining a rear/side extension). Height limit: No part higher than the highest part of the existing roofABC

    Loft enlargement in section: the permitted development limits

    A dormer on the rear slope, with the limits that decide whether it needs planning permission.

    A · Extra roof volume allowed
    40 m³ (terrace house) / 50 m³ (any other house) additional roof volume
    B · Set-back from the eaves
    Original eaves maintained; enlargement set at least 0.2 m from the eaves measured up the roof slope, so far as practicable (not required for hip-to-gable or roofs joining a rear/side extension)
    C · Height limit
    No part higher than the highest part of the existing roof

    Conservation areas, directions and listed houses

    The council publishes 59 conservation areas, and the borough also holds 64 Article 4 directions covering 63 mapped areas. Add 916 listed buildings and the practical result is that many roof alterations need a planning application, even for the same dormer that would be allowed elsewhere.

    The national rule for conservation areas is: Class B roof enlargements are not permitted development on article 2(3) land. Two World Heritage Sites fall within the boundary, and their setting can matter for tall or visible changes: the count is 2.

    There are also 72 tree preservation orders. A protected garden tree can restrict where the scaffold goes.

    Reading the Tower Hamlets decision figures

    The council decided 191 householder applications in the latest year and granted 92.7 per cent, deciding 95.8 per cent within eight weeks or an agreed extension. The sample is small, because a borough of flats receives far fewer house extensions than a suburban one.

    A small sample moves a lot from year to year, so we treat the grant rate as a pointer, not a measure. Read a handful of decisions on your own street and the picture sharpens: look for dormers on the same terrace and note the materials and the set-back.

    We bring those examples into the covering statement, because a local precedent is easier for an officer to weigh than a policy citation.

    Because so many terraces sit inside designated areas, we also prepare a short heritage note for each application. It describes the street, the roof forms around you and what the proposed dormer changes, using photographs taken during the survey. Officers can then judge the effect on the conservation area without a site visit, which helps the application stay on programme.

    Junction, stairs and party walls on Tower Hamlets terraces

    At the join between the main roof and a rear wing the usual set-back rules relax: Eaves-retention and 0.2 m set-back do not apply where the enlargement joins the original roof to the roof of a rear or side extension. That gives the L its single face. The roof can never rise above its original ridge: No part higher than the highest part of the existing roof.

    Terraces here are often party-wall-heavy, and the notice rule is: Party structure notice at least 2 months before work. Stairs are the other tight spot. Where full headroom cannot be reached the guidance is: Loft conversions where 2.0 m cannot be achieved: 1.9 m at the centre of the stair, 1.8 m at the side (half width).

    A new upper level also changes the escape route: 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). We draw the protected route from the loft landing to the front door so building control can follow it.

    Fees and levies

    A fixed quote follows a free constraints check, VAT included. L-shaped dormers have no list price because the roof drives the work. If officers ask for changes we redraw at no charge.

    Tower Hamlets applies its own levy by zone: £335.33/m² (Zone 1); £179.64/m² (Zone 2); £59.88/m² (Zone 3). The Mayoral charge sits in band 2 at £72.73 per square metre this year. Whether a charge reaches your dormer depends on the floor area it creates, and our next-steps pack explains it.

    Related services and neighbouring boroughs

    A simpler roof can be enough: see dormer loft conversion drawings in Tower Hamlets. If your house is a flat-fronted terrace, loft conversion drawings in Tower Hamlets compares the shapes. The wider offer is architectural drawings in Tower Hamlets.

    We also draw L-shaped dormers in Newham, Hackney and Greenwich. The service explainer is L-shaped dormer drawings.

    What you receive

    Planning drawing sheet for a rear extension with plans, elevations and sections
    Sample drawing. Planning drawings for a rear extension: plans, elevations and sections on one sheet set.
    Slate-clad roof extension on a yellow-brick London terraced house
    Storey by storey
    Move up and down — the car travels between floors.

    Other services in Tower Hamlets

    L-shaped dormer drawings nearby

    Questions

    Can I build an L-shaped dormer in a Tower Hamlets conservation area?

    Only with planning permission. Class B roof enlargements are not permitted development on article 2(3) land, and the borough has 59 conservation areas.

    How many Article 4 directions does Tower Hamlets have?

    The council publishes 64. We check whether any removes roof rights on your road.

    What share of householder applications does Tower Hamlets grant?

    92.7 per cent of 191 decisions in the latest figures, a small sample that varies year to year.

    Sources and dates

    City of London skyline glowing at dusk across the Thames under a dramatic orange sky

    Tell us about your property.

    We check the constraints, then send a fixed fee. Messages before 3pm get a reply the same working day.

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