How to Submit a Planning Application in London: Step by Step

Not every home improvement project requires planning permission — many are permitted development (PD). But understanding the boundary between permitted development and works requiring planning permission is essential before committing to a design. Works that always require planning permission in London: any extension on a listed building (permitted development rights do not apply — all works affecting a listed building require listed building consent and may also require planning permission); any extension or alteration in a conservation area where an Article 4 Direction has removed the relevant Class A, B, C, or D permitted development rights; a double-storey rear extension (see the double-storey extension guide); any extension that exceeds the PD volume or projection limits; any new external alterations that change the character of a listed building; any change of use (from residential to commercial, or from one use class to another). Works that may be PD: single-storey rear extensions (up to 3m or 4m projection, or up to 6m/8m under Prior Approval); single-storey side extensions (up to half the original house width); loft conversions (Class B dormers within PD volume limits — see the dormer guide); minor alterations to the external fabric. Applying for a Certificate of Lawful Development (CLOPUD) is strongly recommended before starting any works that the homeowner believes to be PD — this is a formal written confirmation from the LPA that the proposed works are lawful without the need for a planning application. The CLOPUD fee is £258 (as of 2025) — the same as a householder planning application, but the determination standard is a factual assessment of legality rather than a planning merits assessment, and the LPA has a statutory duty to issue the certificate if the proposed works are lawful.

A householder planning application for a rear extension, loft conversion, or other home improvement works in London must include: Application form: the standard application form is submitted online via the Planning Portal (planningportal.co.uk). The form identifies the site (address and Ordnance Survey grid reference), the applicant and agent, the description of the proposed development, and the ownership certificate (confirming that the applicant is the owner of the land or that the owner has been notified). Site location plan (red line plan): an Ordnance Survey-based plan at a scale of 1:1250 or 1:2500, with the application site outlined in red and any other land owned by the applicant outlined in blue. The OS plan is available from the Planning Portal or from OS licensed retailers (typically £30-£60). Block plan (1:500): a plan showing the application site and its immediate surroundings, with the existing and proposed building footprints shown. Existing and proposed drawings: drawn by the architect or surveyor, typically to a scale of 1:100 for floor plans, sections, and elevations. The drawings must show: existing floor plans (ground floor, upper floors if relevant, loft); proposed floor plans showing the new extension or conversion; existing elevations (all four faces of the building) with the proposed changes shown; proposed elevations (showing the extension or conversion in context with the existing building); section drawings (cut through the existing and proposed building, showing roof heights, floor levels, and structural elements). Photographs and photo montages (optional but recommended): LPAs increasingly value photographs of the existing property from the garden, from the street, and from the neighbours' perspective, together with photo montages (Photoshop overlays showing how the extension will look when built). These help the case officer and planning committee understand the proposal in context. Heritage statement (for conservation area applications): where the application is for works in a conservation area or affecting a listed building, a Heritage Statement explaining how the design has been informed by the character and appearance of the conservation area is typically required. Design and access statement (for some applications): a Design and Access Statement is required for certain categories of application — check the specific LPA's requirements. Flood risk assessment (if in a flood risk area): where the site is in Flood Risk Zone 2 or 3 (check the Environment Agency flood map), a Flood Risk Assessment is required. Application fee: householder planning application: £258 (as of 2025, per the Town and Country Planning (Fees for Applications, Deemed Applications, Requests and Site Visits) (England) Regulations 2012, as amended).

The London LPA's decision is made by a planning case officer (for applications under delegated authority — the majority of householder applications) or by the Planning Committee (for applications called to committee by the case officer, a ward councillor, or the applicant). The case officer's assessment against the Development Plan: the case officer assesses the application against the relevant development plan policies, including: the London Plan (the Spatial Development Strategy for London, published by the Mayor of London — currently the 2021 London Plan); the LPA's Local Plan (the adopted local development plan for the borough, which sets out policies for housing, heritage, design, and development in the area); the LPA's Supplementary Planning Documents (SPDs), including Design Guides for householder extensions, Conservation Area Character Appraisals, and Biodiversity or Sustainability SPDs where relevant. The main material planning considerations for a London householder extension: design and character (does the proposed extension respect the character of the original house and the local area? — materials, scale, form, relationship to the street scene); impact on neighbouring amenity (loss of daylight or sunlight to neighbouring windows — 45-degree rule, BRE guidelines; overshadowing of neighbouring gardens; overlooking and loss of privacy from new windows; overbearing impact on neighbouring properties — the extension's scale relative to the neighbours' windows and garden space); impact on heritage significance (in a conservation area or affecting a listed building — does the proposal preserve or enhance the character and appearance of the area?); biodiversity net gain (new requirements under the Environment Act 2021 may apply to some householder applications in certain LPAs); impact on flooding, drainage, and sustainability. Consultation period: after the application is validated (typically 2-5 working days after submission), the LPA consults neighbours (typically within 21 metres of the site), statutory consultees, and relevant internal departments. The standard consultation period is 21 days, during which objections and comments can be submitted. An objection is a material consideration — it is considered by the case officer and must be addressed in the decision notice. An objection does not automatically result in refusal. Statutory determination period: 8 weeks for a householder planning application (56 calendar days from the date of validation). In practice, many London LPA planning departments exceed this target — determination times of 10-16 weeks are common for householder applications in busy London boroughs. The homeowner can agree to extend the statutory period if the case officer requests more time.

A planning refusal is not the end of the road — it is an opportunity to understand what the LPA's objections are and to redesign the proposal to address them. Options after a planning refusal: Review the decision notice carefully: the decision notice explains the specific reasons for refusal. Reasons for refusal are written in relation to the development plan policies that the proposal is considered to conflict with. The reasons must be specific and must relate to material planning considerations — a refusal based on a non-material consideration (the neighbour's personal objection that is not a planning matter) can be challenged at appeal. Request a pre-application meeting with the case officer: after a refusal, most London LPAs allow the applicant to meet with the case officer to understand exactly what design changes would resolve the refusal reasons. This is the most efficient route to a successful resubmission — it avoids the homeowner guessing what changes are required. Resubmit a revised application (free resubmission within 12 months): under the Planning (Listed Buildings and Conservation Areas) Act 1990 and associated regulations, a resubmission of a planning application for a householder extension within 12 months of a refusal is exempt from the planning fee — the second application is free. The resubmitted application must address the reasons for refusal. Lodge a planning appeal to the Planning Inspectorate: a planning appeal (under Section 78 of the Town and Country Planning Act 1990) must be lodged within 6 months of the refusal. The appeal is determined by an independent Planning Inspector appointed by the Planning Inspectorate. For a householder extension appeal, the written representations procedure is the standard route (written statements from the applicant, the LPA, and interested parties). An appeal typically takes 3-6 months to determine. The appeal is considered on the merits of the case — if the refusal reasons are not soundly based in planning policy, the Inspector may allow the appeal. Planning appeals have a success rate of approximately 30-35% nationally for all appeal types — for householder extension appeals, the success rate is broadly similar. Use a planning consultant to advise: if the refusal reasons appear to conflict with planning policy, or if the LPA appears to have applied its policies inconsistently, a planning consultant's assessment is valuable before deciding whether to resubmit or appeal.