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Islington, London

Side return extension drawings in Islington

Victorian terraces with a side return are common in Islington, and the council has a stated view on them. Our side return extension drawings for Islington start at £745 including VAT, and they are drawn around two tests in the borough's design guide: how much garden is left, and what happens to the gap at the corner of the return.

From £745 (VAT included)

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  • 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 side return extension 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 house being extended, with a wide new opening supported over the ground floor

    What the Urban Design Guide says about a side return in Islington

    The borough's Islington Urban Design Guide SPD deals with side returns directly. It treats ground and lower-ground extensions into the lightwell, the narrow side space beside the rear addition, or beyond the back addition as normally acceptable, so long as enough usable garden is kept.

    It is more guarded about the corner. The gap at the corner of the return on Victorian and Edwardian terraces should normally be kept. Infill is considered only for an especially long gap, or to replace an incongruous structure, and the guide limits that to land outside conservation areas.

    In practice that gives you two drawings to get right. The first is the garden: we measure what remains after the extension and show it. The second is the corner: if the gap is short and the street is uniform, we tell you early that the council may resist a full infill and show what a stepped or part-width scheme can achieve.

    Finished white-rendered rear house extension with large glazed doors

    Local figures for Islington

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Supplementary planning documentIslington Urban Design Guide SPD2017islington.gov.uk
    Conservation areas41 named conservation areas published by the council—planning.data.gov.uk
    Listed building entries1,050 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Households living in a house16.3 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Owner-occupied households26.7 % of households owner-occupied (owned outright or with mortgage/loan)Census 2021nomisweb.co.uk
    Average price, terraced1,151,398 GBP2026-07publicdata.landregistry.gov.uk
    Householder decisions337 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted92.6 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time98.8 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Borough CIL residential rate£300/m² (Zone A); £250/m² (Zone B) — residential dwellings, Use Classes C3 and C4schedule rate (approved 26 June 2014, effective 1 September 2014)islington.gov.uk
    Householder: alterations/extensions to a single dwellinghouse, from 1 Apr 2026548 GBP—ribblevalley.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 Islington

    Householder applications by street in Islington

    Streets in Islington with the most householder applications, and the share approved
    StreetApplicationsApproved
    Corbyn Street3585%
    Plimsoll Road2893%
    Aberdeen Park2491%
    Thorpedale Road2190%
    Highbury Hill2094%
    Hungerford Road2088%
    Sussex Way18100%
    Avenell Road1585%
    Hemingford Road1579%
    Huddleston Road15100%
    Romilly Road1592%
    Harberton Road14100%
    Offord Road1486%
    St George's Avenue14100%
    Thornhill Road1479%
    Counts of householder applications by street; no individual applications are shown. Streets with fewer than five applications are left out.Source: GLA Planning London Datahub, householder applications, all years held. Contains public sector information licensed under the Open Government Licence v3.0. Contains OS data © Crown copyright and database right 2026.
    The 45-degree test in planTest used in daylight assessments: 45 degrees (plan and elevation). Islington guidance: 45 degrees (plan and elevation)AB

    The 45-degree test in plan

    A line from the middle of the neighbour's nearest window: the extension should stay behind it.

    A · Test used in daylight assessments
    45 degrees (plan and elevation)
    B · Islington guidance
    45 degrees (plan and elevation)

    Conservation areas and listed buildings in Islington

    The council publishes 41 conservation areas. National permitted development gives no side extensions in them: No side extensions under PD on article 2(3) land (conservation areas etc.). A side return in one of them is a householder application, and the officer reads the drawings against the area's character.

    Historic England lists 1,050 entries inside the boundary. If yours is listed, listed building consent is a separate application and the extension is judged much more narrowly.

    On an Islington house outside every designation, the national limit is: Side extension: single storey, max 4 m high, max half the width of the original house.

    Housing and decisions in Islington

    Only 16.3 per cent of households live in a house, as the borough is mostly flats, and 26.7 per cent own their home. That makes each terrace owner's side return a small, high-value project: the average terraced house sold for £1,151,398 in the latest figures and the average semi for £1,406,430.

    Islington decided 337 householder applications in the latest twelve months, granted 92.6 per cent and decided 98.8 per cent within eight weeks or an agreed extension. Those are borough-wide figures for every kind of householder scheme, not a forecast for yours.

    A side return in Islington is rarely a standalone job. It is often combined with a rear addition or a lower-ground kitchen, and each move changes how the officer reads the garden test. We therefore draw the proposed garden at a scale that shows its remaining depth and the planting, and we mark the line of the corner gap on the plan, so the whole composition is judged at once.

    Party walls, glazing and cost for an Islington side return

    A terrace side return rests on the neighbour's flank wall, often a shared historic one. Where a new wall is built on the line, the Act requires: Line-of-junction (new wall) notice at least 1 month before work. Cutting into the shared structure needs: Party structure notice at least 2 months before work. Our party wall notices service prepares them to match the drawings.

    Approved Document L caps the glass in the new room: Windows, roof windows, rooflights and doors in an extension should not exceed 25% of the extension floor area plus the area of openings removed or covered. Islington's planning fee for householder work is £548. The borough levy is shown as £300/m² (Zone A); £250/m² (Zone B) — residential dwellings, Use Classes C3 and C4.

    Taking out the old flank wall needs a beam, and the engineer's sizes go on our sheets. The structural side is covered by structural calculations in Islington.

    What the Islington set includes

    Existing and proposed plans, elevations and sections, with location and block plans, at a fixed £745. Each sheet is checked by a second chartered technologist, and if Islington's officer asks for amendments we make them free of charge.

    If the back of the house is changing too, see rear extension drawings in Islington, or the overview at architectural drawings in Islington.

    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.
    Two-storey rear extension under construction on a semi-detached house
    Every side considered
    Flick across the turntable to spin it.

    Other services in Islington

    Side return extension drawings nearby

    Questions

    Will Islington let me fill the whole side return?

    It depends on the corner gap. The design guide normally keeps the gap at the corner of the return on Victorian and Edwardian terraces, and considers infill only for an especially long gap or to replace an incongruous structure.

    Is a lightwell extension acceptable?

    Usually, if enough usable garden is kept, according to the Urban Design Guide.

    Do I need permission in an Islington conservation area?

    Yes for a side extension. The borough has 41, and No side extensions under PD on article 2(3) land (conservation areas etc.).

    How much is the Islington planning fee?

    £548 for householder work, payable to Islington.

    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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