020 7864 7245Request a fixed quote

Barnet, London

Retrospective planning application in Barnet

A retrospective planning application in Barnet asks the council to grant permission for work already built. Barnet is a borough where refusals are often challenged: of 413 householder appeals decided over five years, 50.6 per cent were allowed. We survey the building, draw it as it stands, and tell you plainly whether to apply, amend or appeal.

Fixed quote after a free constraints check

  • MCIAT chartered
  • £2m PI insured
  • LABC Partnered
  • Fixed fees, VAT included

Request a fixed quote

We use it to check conservation areas and constraints.
Pick the council that decides your application.
A few lines: what you want to build, and anything the council has already said.
Add photos or drawings

Drop files here or choose from your device

PDF, JPG, PNG, DWG · up to 10 files, 90 MB in total

    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.

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

    The Barnet guidance that governs finished work

    The council writes no separate test for retrospective cases. The same documents apply as to new proposals: the Barnet Local Plan 2021-2036, adopted in 2,025, and the guidance on residential extensions and alterations, which is Sustainable Design and Development Guidance SPD, Part 4: Guidance on residential extensions and alterations, together with the design principles in Sustainable Design and Development Guidance SPD, Part 2: The seven features of good design.

    Both guidance parts are recent, so work built some years ago is judged against rules that may be stricter or looser than those in force when it went up. That tells you nothing about lawfulness. We read the current guidance on depth, height and roof form, then compare the building with it measurement by measurement.

    The outcome of that comparison tells us the route, and it is the first thing we report back to you, in writing, before you commit to a quote for the full set of drawings. A building inside the guidance needs a straightforward application. One that exceeds it by a little may be defended on its merits. One that exceeds it by a lot probably needs amendment before you apply.

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

    Local figures for Barnet

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Householder appeals decided by the Planning Inspectorate413 householder appeals decideddecision dates 1 Jul 2021 to 30 Jun 2026assets.publishing.service.gov.uk
    Householder appeals allowed50.6 % of householder appeals alloweddecision dates 1 Jul 2021 to 30 Jun 2026assets.publishing.service.gov.uk
    Householder decisions1,361 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted80.2 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Lawful development certificate applications (PS1)785 certificates2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Green Belt share of the council area28 % of council area covered by green-belt polygons—planning.data.gov.uk
    Tree preservation orders718 tree preservation orders published by the council—planning.data.gov.uk
    TCPA 1990 s171B(1)-(3) as substituted by LURA 2023 s115, in force 25 Apr 202410 years—legislation.gov.uk
    Householder: alterations/extensions to a single dwellinghouse, from 1 Apr 2026548 GBP—ribblevalley.gov.uk
    DMPO 2015 art 37(2)(a): householder appeal, from the date of the decision notice12 weeks—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 Barnet
    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

    Appeal outcomes in Barnet, and why they matter here

    Planning Inspectorate casework shows that Barnet decided 413 householder appeals over a five year period, and that 50.6 per cent were allowed. That is the share of appealed refusals which an independent inspector overturned.

    It is a fact about past appeals, not a forecast for yours. But it tells us the council's refusals are tested in practice, so a retrospective refusal is worth examining rather than accepting. If the council turns you down, the householder appeal limit is 12 weeks, and our planning appeals service in Barnet can take over.

    In its latest year the council also decided 1,361 householder applications, granted 80.2 per cent and decided 95.1 per cent in time.

    Green Belt and protected trees in Barnet

    About 28 per cent of Barnet is Green Belt, and the council has published 718 tree preservation orders covering 3,219 mapped zones. Both matter more for finished work than for a proposal, because they cannot be designed around after the event.

    In Green Belt, an extension that is disproportionate to the original house is hard to defend, however well drawn. For trees, a rear extension built over roots, or with a canopy cut back without notice, can bring a separate enforcement problem, so we ask for dated photographs and for any tree-works notices in your files. Aerial images from different years, which are freely available online, can also help fix when a structure appeared, and they often settle questions that the owner cannot answer from memory.

    Elsewhere the borough has 16 conservation areas, 15 Article 4 directions and 651 listed entries to check.

    Enforcement limits and the lawful alternative

    The time limit for enforcement against most unauthorised building works is 10 years. After it, a lawful development certificate in Barnet may be a better answer than a planning application. Barnet received 785 lawful development certificate cases in its latest annual returns, so the route is well used.

    Before the limit, the council may decline to determine an application that overlaps an enforcement notice served earlier. The sensible time to act is before a notice arrives. If one has already been served, tell us at once, because its date and wording decide which routes remain open and how little time you have left to appeal against it.

    Drawings, fee and what we charge

    We start from a measured building survey and draw the building as built, with a schedule of differences against any earlier approval. The council's householder fee is £548, and it decides within 8 weeks unless you agree longer.

    Our price is fixed after the free constraints check. For the wider borough see architectural drawings in Barnet, or compare retrospective applications in Brent and Harrow.

    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.
    Pencil resting on a dimensioned technical drawing beside a scale rule
    The street around you
    Move across the plinth — the blocks rise around the pointer.

    Other services in Barnet

    Retrospective planning applications nearby

    Questions

    Does a high appeal success rate mean my retrospective application succeeds?

    No. It shows that refusals taken to appeal in Barnet are often overturned, not that any particular application will be granted. We assess your building on its own facts.

    My extension is in the Green Belt. Is there any point applying?

    Possibly, if the extension is modest against the original house. If it is large we say so frankly, and may suggest reducing it first.

    How long does the council take?

    8 weeks for a householder application, unless you agree an extension.

    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.

    Request a fixed quoteCall 020 7864 7245WhatsApp