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Croydon, London

Retrospective planning applications in Croydon

Croydon is a borough of suburban houses with long back gardens, and that is where unauthorised building usually happens: the extension that grew, the outbuilding that became a home. The council can still grant permission after the event. We survey what stands, draw it and prepare the application. Fixed quote after a free constraints check.

Fixed quote after a free constraints check

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We use it to check conservation areas and constraints.
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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 retrospective planning applications

    Seven 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.

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

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    Georgian brick terrace with sash windows, arched fanlight doorways, stone steps and iron railings in London

    What Croydon applies to work already built

    We found no rule from Croydon aimed only at retrospective applications. The council uses the Croydon Local Plan 2018, adopted in 2,018, and, where a conservation area is involved, the Conservation Areas General Guidance SPD. The approach is the same as for a new proposal: would this building have been acceptable here if you had asked first?

    Croydon also has long terraces and inter-war semis where side extensions were common. Where a side extension left a very narrow gap to the boundary, officers look at whether a terracing effect is created. We draw the gap carefully, since a few centimetres can be the difference.

    The test that decides most Croydon extension cases is the effect on neighbours and the character of the street. A rear extension that blocks light to a neighbour's kitchen window, or a roof extension that breaks a terrace, is judged on what it does now. Having built it already earns no credit, and a deliberate breach can count against the application under national policy.

    We therefore draw the as-built extension, show sight lines and distances to the neighbouring windows, and explain in plain terms why the harm is limited. Neighbours are consulted on retrospective applications too, so a short, honest account helps.

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

    Local figures for Croydon

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Domestic gardens share of land (GLUD 2005)32.8 % of land that is domestic garden (GLUD 2005)2005data.london.gov.uk
    Householder decisions786 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted86.6 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time94.4 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Minor applications granted57.6 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Lawful development certificate applications (PS1)494 certificates2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Larger home extension prior approvals granted17 decisions2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Larger home extension prior approvals refused34 decisions2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Conservation areas19 named conservation areas published by the council—planning.data.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 Croydon
    Which application your project needsLawful Development Certificate decision: 8 weeks. Prior approval decision: 42 days. Householder decision: 8 weeksYour projectWithin permitted development?Lawful Development CertificatePrior approvalHouseholder applicationYesLarger rear extensionNoABC

    Which application your project needs

    The usual route for a house; flats and listed buildings follow other rules.

    A · Lawful Development Certificate decision
    8 weeks
    B · Prior approval decision
    42 days
    C · Householder decision
    8 weeks

    Gardens, outbuildings and the beds-in-sheds problem

    Gardens make up 32.8 per cent of the land in the borough, so outbuildings are common. An outbuilding is permitted development only within limits on height, area and use, and one used as a separate dwelling needs planning permission in its own right.

    If a garden building has been let or lived in, a retrospective application for an ancillary outbuilding will not fix that. We say so frankly. If the building is truly ancillary, we draw it as built and show its use and size against the permitted development limits.

    The borough has an Article 4 direction on houses in multiple occupation, so a house converted for several unrelated sharers is a separate planning question that needs its own application.

    Large extensions and prior approval in Croydon

    Larger single-storey rear extensions go through a prior approval process. In the government return the council granted 17 and refused 34 such notifications, so refusals outnumber grants in the figures.

    When an owner builds before the process finishes, or builds beyond the size notified, the extension stands outside permitted development and needs a full retrospective application. Our prior approval drawings in Croydon page explains the process for new work, and a retrospective case starts from the as-built depth and height.

    We measure to the millimetre, because a few centimetres over the limit changes the route.

    Figures for householder applications

    Croydon decided 786 householder applications in its latest year, granted 86.6 per cent and decided 94.4 per cent in time. Minor applications were granted at 57.6 per cent, lower than householder cases, which suggests a flat conversion or new building is a harder case than an extension.

    The council also recorded 494 certificate of lawfulness applications, a high figure that reflects how many owners try to prove that older building work is lawful. If yours is more than 10 years old, lawful development certificates in Croydon are the first thing to check.

    The borough has 19 conservation areas and 25 per cent Green Belt, which affect the test in the south of the borough.

    Fee, timing and what we prepare

    A householder retrospective application costs £548 where the house qualifies, and the council has 8 weeks to decide. If the decision is a refusal, you have 12 weeks to appeal.

    If the council raises an objection from a neighbour, we answer it directly and with drawings, not with general comment. A neighbour who sees their concern addressed on paper is less likely to escalate.

    We prepare the survey, as-built drawings and a short statement, then submit through the planning portal after a second MCIAT chartered architectural technologist has checked the set. Other services in the borough are on the Croydon hub, and the national rules are on the retrospective planning hub.

    Send us the address, the dates of the work and any letters from the council. We confirm the route and a fixed quote after a free constraints check.

    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.
    Rear view of brick terraced houses in London with slate roofs and chimney stacks along the shared roofline
    The street around you
    Move across the plinth — the blocks rise around the pointer.

    Other services in Croydon

    Retrospective planning applications nearby

    Questions

    Can I keep a garden building I already built in Croydon?

    Possibly, if it is ancillary to the house and acceptable on size and effect. A building used as a separate home needs permission as a dwelling, which is a harder case.

    My extension is a few centimetres too deep. What now?

    Over the permitted limit it needs permission, so a retrospective application is the usual route. We measure the extension and draw it as it stands.

    Will neighbours be told?

    Yes. The council notifies neighbours of a retrospective application as it would for any other, and their comments are considered.

    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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