Planning Appeals for London Home Extensions 2025: What to Do When Planning Is Refused

The planning refusal notice: when a London Borough refuses a planning application, it issues a formal PLANNING REFUSAL NOTICE that states the reasons for refusal; each reason for refusal identifies: the policy (or policies) under which the application has been refused (for example: the Borough's Local Plan housing extension policy; the London Plan housing design standard; the NPPF guidance on residential amenity or heritage assets); the specific ground on which the application has been judged to conflict with that policy (for example: "the proposed rear extension would result in an unacceptable loss of daylight to the neighbouring property at 45 Anystreet due to the BRE 25° vertical sky component test not being met"); understanding the reasons for refusal is essential because the refusal reasons determine: whether the refusal is sound (the LPA applied the correct policy correctly to the specific facts) or weak (the LPA misapplied the policy, applied it too restrictively, or failed to weigh the benefits against the harm); whether the application can be improved by modification (for example: reducing the height of the extension to comply with the daylight test; reducing the depth of the extension to comply with the overlooking policy; adding a privacy screen to a proposed balcony); whether an appeal is appropriate (if the refusal is based on a weak planning ground that a Planning Inspector is likely to disagree with). Common grounds for refusal of a London home extension planning application: LOSS OF DAYLIGHT/SUNLIGHT TO NEIGHBOURING PROPERTY (the most common refusal reason in London): the BRE (Building Research Establishment) guidelines on daylight and sunlight to residential developments are widely used by London Borough planning officers to assess the impact of proposed extensions on the daylight received by the windows of neighbouring properties; the key tests: Vertical Sky Component (VSC) test: the VSC of the neighbouring window (the proportion of the sky visible from the centre of the window) should not be reduced by more than 20% of its existing level by the proposed extension; No Sky Line (NSL) test: the proportion of the floor area of the neighbouring room that can see the sky through any window should not be reduced to less than 0.8 of its existing value; where the proposed extension fails these tests in relation to a neighbouring window, the LPA may refuse on daylight grounds; LOSS OF OUTLOOK / OVERBEARING IMPACT: many London Borough Local Plans contain policies against development that would be "overbearing" to neighbouring properties — creating a sense of enclosure or significantly reducing the sense of open space for the occupants of the neighbouring property; this is particularly common where a proposed extension would be close to the neighbouring property's habitable room windows or garden; LOSS OF PRIVACY / OVERLOOKING: policies against new windows (particularly on side elevations or elevated rear areas) that overlook the private garden or habitable rooms of a neighbouring property; a proposed balcony or raised terrace that looks directly into the neighbouring garden is a common overlooking refusal ground in London; OUT OF CHARACTER WITH THE AREA / DESIGN GROUNDS: the proposed extension does not respect the character and appearance of the existing house or the wider street; this is particularly relevant in conservation areas where design guidance is more prescriptive; HARM TO A HERITAGE ASSET: in a conservation area or in relation to a listed building, the proposed extension is considered to cause harm to the significance of the heritage asset (the character and appearance of the conservation area, or the architectural or historic significance of the listed building); LOSS OF TREES / PROTECTED SPECIES: where the proposed development requires the removal of a protected tree (subject to a Tree Preservation Order — TPO) or would harm a protected species (for example, bats roosting in the roof space to be converted), the LPA may refuse on ecological grounds. Assessing whether to appeal, modify and resubmit, or redesign: THE FIRST STEP AFTER REFUSAL is to read the refusal notice carefully and (ideally with the help of a planning consultant or chartered architect who has experience with the relevant London Borough and planning policies) to assess: IS THE REFUSAL WELL-FOUNDED? (Is the LPA's assessment of the policy correct? Has the daylight test been applied correctly? Is the overlooking concern proportionate?) If the refusal appears to be based on weak grounds or an incorrect application of the policy, an appeal may be the appropriate route. IS THE DEVELOPMENT MODIFIABLE? (Can the extension be redesigned to overcome the refusal reason — for example, by reducing the height, depth, or width; by changing the roof profile; by adding obscure glazing on a side elevation; by omitting a proposed balcony?) If the development can be modified to overcome the refusal without significantly compromising the client's brief, a RESUBMISSION WITH MODIFICATIONS is typically faster and cheaper than an appeal. IS PRE-APPLICATION ENGAGEMENT APPROPRIATE? (Most London Boroughs offer a PRE-APPLICATION PLANNING ADVICE SERVICE where the planning officer provides informal advice on whether a proposed development is likely to be acceptable before a formal application is made; using pre-application advice before a resubmission can significantly increase the prospects of approval.) IS THE MATTER TIME-SENSITIVE? (If the development is time-critical, a resubmission may be faster than an appeal — a written representations appeal typically takes 6-9 months from submission to decision.)

The planning appeal process for a London home extension — how it works: the right of appeal: a homeowner whose planning application has been refused (or who has not received a decision within the statutory 8-week determination period) has a RIGHT OF APPEAL to the Planning Inspectorate under Section 78 of the Town and Country Planning Act 1990; the appeal must be submitted within 6 MONTHS of the date of the refusal notice (for householder appeals — extensions and alterations to a dwellinghouse); the planning appeal is heard and decided by a PLANNING INSPECTOR (appointed by the Planning Inspectorate on behalf of the Secretary of State) — NOT by the Local Planning Authority; the Inspector is independent and will make their own assessment of whether the development is consistent with the development plan (the local authority's Local Plan and the London Plan) and any other material considerations (including the NPPF); TYPES OF PLANNING APPEAL PROCEDURE: WRITTEN REPRESENTATIONS (the fastest and most common procedure for householder appeals in London): the appellant (the homeowner) and the LPA both submit written statements explaining their case; there is no hearing or oral evidence; the Planning Inspector visits the site and considers the written statements; decision: typically 6-9 months from appeal submission; cost: no hearing costs (but planning consultant's fees for preparing the appeal statement); SUCCESS RATE: the national success rate for householder planning appeals (written representations) is approximately 37% (2024/25 — MHCLG statistical release); this varies significantly by London Borough and by the nature of the refusal reasons; an appeal against a refusal on daylight/sunlight grounds where a detailed BRE assessment supports the proposal has a significantly higher success rate than an appeal against a refusal on design/character grounds in a sensitive conservation area; HEARINGS AND PUBLIC INQUIRIES: for more complex cases, the Planning Inspector may hold a HEARING (an informal session where all parties present their evidence in person — more commonly used for commercial or larger residential developments rather than a simple householder extension); a full PUBLIC INQUIRY is rarely used for a single householder extension appeal; COSTS AWARDS: the Planning Inspectorate can award costs against either party to an appeal if the party has behaved unreasonably in the appeal process (for example, if the LPA has refused an application on a ground that is manifestly weak and has then failed to justify the refusal in the appeal process, the Inspectorate may award costs against the LPA; conversely, if the appellant has submitted an appeal that is manifestly without merit, costs may be awarded against the appellant). The appeal statement — what it should contain: a planning appeal statement for a London householder extension should: ADDRESS EACH REASON FOR REFUSAL IN TURN — explain why the proposed development does not conflict with the relevant policy, or why the LPA has misapplied or over-restrictively interpreted the policy; CITE THE RELEVANT PLANNING POLICIES — the development plan (Local Plan policies for residential extensions, conservation area policies, the London Plan housing standards); national policy (the NPPF — particularly the presumption in favour of sustainable development and the balance between housing needs and amenity impacts); WHERE DAYLIGHT/SUNLIGHT IS AT ISSUE: commission a formal BRE daylight and sunlight assessment (to VSC and NSL standards) from a qualified daylight consultant; this provides objective evidence to counter the LPA's daylight assessment; SUBMIT PLANS, PHOTOGRAPHS, AND CONTEXTUAL ANALYSIS — to support the argument that the proposed extension is proportionate and appropriate; PRE-APPLICATION ADVICE (if any was obtained) — if the planning officer gave any pre-application advice that was positive about the proposed development (and then refused it on the same or similar grounds), this inconsistency is highly relevant to the appeal. Improving the prospects of success: the most common reasons why planning appeals for London home extensions fail: THE APPEAL ARGUMENTS DO NOT DIRECTLY ADDRESS THE REFUSAL REASONS (restating the application rather than specifically refuting the LPA's policy analysis); THE EVIDENCE BASE IS WEAK (particularly for daylight/sunlight grounds — a formal BRE assessment is strongly recommended where daylight is at issue); THE DEVELOPMENT IS GENUINELY HARMFUL (some planning refusals are well-founded — the development is too large, too close to the neighbour's windows, or genuinely out of character with the area; where this is the case, a redesign and resubmission may be more appropriate than an appeal); NOT INSTRUCTING A PLANNING CONSULTANT: a planning consultant who has experience with the relevant London Borough's policies and with the Planning Inspectorate's approach to householder appeals can significantly increase the prospects of appeal success; the consultant's fee (typically £2,000-£6,000 for a written representations appeal) is usually worthwhile if the proposed development is significant.

Alternatives to a planning appeal for a refused London home extension: the planning appeal is not always the best response to a planning refusal — in many cases, a resubmission with modifications or a redesign is faster, cheaper, and more likely to result in a successful outcome: RESUBMISSION WITH MODIFICATIONS: if the development can be redesigned to overcome the specific refusal reasons (for example: reducing the rear extension depth by 0.5m to pass the BRE daylight test; omitting a proposed balcony that overlooked the neighbour's garden; reducing the height of a side extension to below the eaves of the existing house; using a pitched roof instead of a flat roof to reduce massing), a RESUBMISSION is typically the right route; the resubmission does NOT need to be a completely new application — it can be submitted as a revised application addressing the specific refusal reasons; RESUBMISSION FEE EXEMPTION: a resubmission of a householder application (that was previously refused or withdrawn) is FREE within 12 months of the original application being determined or withdrawn (one free resubmission only); the free resubmission allows the homeowner to submit a revised application addressing the refusal reasons without paying the standard planning application fee (£258 for a householder application); the free resubmission must be to the same LPA, for the same site, for substantially the same development (with modifications to address the refusal). PRE-APPLICATION PLANNING ADVICE: most London Boroughs offer a PRE-APPLICATION PLANNING ADVICE SERVICE where a planning officer will provide written or meeting-based advice on whether a proposed development is likely to be acceptable in principle — BEFORE a formal application is made; pre-application advice is particularly valuable: before a resubmission (to confirm that the proposed modifications are likely to overcome the refusal reasons); before a first application (to avoid a foreseeable refusal on well-established grounds); for development in a conservation area or relating to a listed building (where the design guidance is more prescriptive and the planning risk is higher); PRE-APPLICATION ADVICE FEES: London Boroughs charge for pre-application advice (unlike planning applications themselves, which are nationally set); typical fees for a householder pre-application meeting in London: £100-£600 depending on the Borough and the type of meeting (written advice vs officer meeting vs design review panel); Camden, Kensington and Chelsea, Westminster, and Southwark typically have higher pre-application fees than outer London Boroughs; SECTION 73 APPLICATION (VARYING A CONDITION ON A PLANNING PERMISSION): where a planning permission has already been granted for the development (subject to conditions) and the applicant wants to vary one of the conditions (for example: varying a condition requiring the use of specific materials, or varying the approved drawings to increase the size of a window), a SECTION 73 APPLICATION (under Section 73 of the TCPA 1990) can be made; a Section 73 application is processed as a new planning application and has a standard fee of £258; the LPA must consider whether the variation is acceptable — but the starting point is that the principle of development has already been established by the original permission; PERMITTED DEVELOPMENT (LDC ROUTE): where the refused planning application was for an extension that could have been redesigned to fall within the permitted development rights (for example: the refused application was for a 5.5m rear extension, but a 6m rear extension is achievable as permitted development with the NCP procedure), the homeowner should consider abandoning the planning application and instead proceeding with a design that falls within the PDR envelope and applying for a Lawful Development Certificate; CONTACTING THE WARD COUNCILLORS: for applications that are supported by the Ward Councillors (the elected local councillors for the area in which the property is located), the planning officer's DELEGATED REFUSAL can sometimes be "called in" to the Planning Committee for determination; at the Planning Committee, Ward Councillors can speak in support of the application and the Planning Committee members can override the planning officer's recommendation to refuse — granting the permission despite the officer's recommendation; this route is most appropriate where the application is borderline (i.e., the refusal reasons are not clear-cut) and where the Ward Councillors are sympathetic to the applicant's case.