Planning Permission in Harrow
Fixed-fee, MCIAT-chartered planning permission for Harrow homeowners — London Borough of Harrow validation and local constraints handled from the start.
Harrow is Metro-land in built form: rows of interwar semi-detached and detached houses across Rayners Lane, Kenton, Stanmore and Wealdstone that lend themselves to hip-to-gable and dormer loft conversions and rear extensions. On these homes such work frequently qualifies as permitted development within the volume limits, so a full application is not always needed. The London Borough of Harrow pays close attention to preserving the rhythm and consistent 1930s building line of these suburban streets, and expects extensions to respect the established line and roof form of the neighbouring houses.
The picture changes in the borough's heritage cores. Harrow on the Hill carries a protected heritage setting and long views, and Pinner's medieval high street and Pinner Hill, along with Roxeth and Harrow Weald, are conservation areas where permitted development is often restricted and a full, context-led application is required. Harrow also applies Article 4 directions to HMO conversions in designated wards and to front-boundary and hardstanding works in some areas, so the right route depends on your exact address rather than the house type alone.
We prepare Harrow planning drawings that respect the building line and roof form the borough expects, checking permitted development eligibility for semi-detached and detached homes first and confirming it with a Lawful Development Certificate where the work qualifies. In the conservation areas we design to the character of the area — materials, proportions and rooflines — and evidence the heritage considerations so the submission stands up. The fee is fixed and agreed up front, usually around 30% below an architect's charge for the same council-accepted drawings, with free redraws until Harrow approves. Drawing to the council's validation checklist, and turning drawings around in roughly seven days, keeps most applications inside the statutory eight-week determination without a validation query.
Planning in Harrow: what to know before you apply
Harrow applies Article 4 directions to HMO conversions in designated wards and controls development within Harrow on the Hill and Pinner conservation areas. For the borough's abundant 1930s semis, hip-to-gable lofts and rear extensions frequently qualify as permitted development.
Typical Harrow housing stock
Classic Metro-land interwar semi-detached and detached houses, with the historic hilltop core of Harrow on the Hill and Pinner's medieval high street.
Areas we regularly draw for in Harrow
Harrow · Pinner · Stanmore · Wealdstone · Rayners Lane · Kenton · Hatch End
What the numbers say about Harrow planning decisions
These are London Borough of Harrow’s own reported figures, published by government rather than estimated by us. They are what we design against — a borough that refuses one householder application in five needs a different drawing package from one that refuses one in twenty.
Householder decisions in Harrow
Every householder application London Borough of Harrow decided over the four quarters to 2026 Q1.
| Householder applications decided | 894 |
|---|---|
| Granted | 739 |
| Refused | 155 |
| GrantedEngland average 90% | 83% |
| Of which prior approvalsPrior approvals are granted far more often than full applications, so this share moves the rate above | 24% |
| Decided within 8 weeksExcludes prior approvals. England average 93% | 94% |
Source: Ministry of Housing, Communities and Local Government (PS2 district planning application statistics). Open Government Licence v3.0 Extracted 2026-08-16.
Permitted development in Harrow
Larger householder extensions put to London Borough of Harrow under the prior-approval route, and lawful-development certificates decided, over eight quarters.
| Prior approval not requiredWent ahead without a full application | 617 |
|---|---|
| Prior approval granted | 47 |
| Prior approval refused | 171 |
| Granted where a decision was neededFrom 218 determinations | 22% |
| Building upwards, prior approval refused | 0 |
| Certificates of lawful development decided | 584 |
Source: Ministry of Housing, Communities and Local Government (PS1 district planning application statistics). Open Government Licence v3.0 Extracted 2026-08-16.
Designated areas in Harrow
Conservation areas London Borough of Harrow has published to the national register, and when it designated them. Where a borough has supplied no Article 4 data the row is omitted rather than shown as zero.
| Conservation areas on the register | 27 |
|---|
Source: MHCLG Planning Data Platform. Open Government Licence v3.0 Extracted 2026-08-16.
If London Borough of Harrow refuses: appeal outcomes
Planning appeals against London Borough of Harrow determined by the Planning Inspectorate, 2021–2026. Enforcement notices and withdrawn cases are excluded.
| Appeals determined | 609 |
|---|---|
| Allowed | 214 |
| Dismissed | 395 |
| Householder appeals allowedFrom 319 householder appeals. England average 36% | 42% |
Source: Planning Inspectorate appeals casework. Open Government Licence v3.0 Extracted 2026-08-16.
Planning Permission for Harrow homes: the package and the process
A householder application is refused validation far more often than it is refused permission, and almost always for the same reasons: a location plan at the wrong scale, no red line around the application site, a missing ownership certificate, or elevations that do not show every face of the building affected. We prepare the full submission set — location plan, block plan, existing and proposed floor plans, elevations and sections — so the case officer receives a complete case on day one.
Once the application is live we stay on it. Officers routinely come back with questions about materials, boundary treatment or a dimension they cannot read off the drawings, and a fast, drawn answer is usually the difference between a decision inside the statutory period and a request to withdraw and resubmit.
Which route applies is decided by the building before it is decided by policy. A house that has never been extended usually has allowances left to use; a flat, a listed building or a home in a conservation area often has none, and the same drawing set then has to make a design case rather than a compliance one.
Do I need planning permission for an extension in London?
Many single-storey rear extensions, loft conversions and outbuildings fall under permitted development rights and do not need a full planning application — but London's dense housing stock, conservation areas and Article 4 directions frequently withdraw those rights. Before you pay for a full application, we check your property against the current permitted development thresholds and your borough's local constraints.
Where permitted development applies, we recommend a Lawful Development Certificate instead of full planning — it is faster, cheaper and gives you a legal document confirming the work was lawful. Where a full application is genuinely required, we prepare it properly the first time.
Permitted development vs a full planning application
Permitted development lets you build within defined volumetric limits without committee review. A full householder application is assessed against the borough's local plan for scale, daylight, neighbour impact and design. We advise which route your project qualifies for and why.
Article 4 directions and conservation areas
If your home sits in a conservation area or under an Article 4 direction, permitted development rights are often removed — meaning even modest changes need consent. Each borough page lists the local directions and conservation areas we routinely design around.
How do you apply for planning permission through the London Planning Portal?
We manage the full lifecycle of your submission — survey, drawings, supporting documents and officer liaison — so you never have to decode a validation checklist yourself.
Phase 1 — existing and proposed site surveys
A laser-measured survey captures your property exactly, so existing and proposed drawings match reality millimetre for millimetre.
Phase 2 — technical drawing package
Site location plan, block plan, floor plans, elevations and sections drawn to your borough's scale and formatting requirements, with a design and access statement where needed.
Phase 3 — liaison with the planning officer
We answer the council's queries, negotiate amendments, and redraw free until the decision lands.
How long does planning permission take, and what does it cost?
Drawings are typically ready within 7 days of survey. Your council then has a statutory 8 weeks to decide a householder application. Our drawing fees are fixed and quoted upfront — the table below shows typical packages.
| Package | Production window | Compliance layer | Typical fee |
|---|---|---|---|
| Permitted Development pack | 7–10 working days | Lawful Development Certificate submission | £950–£1,450 |
| Full Planning pack | 10–14 working days | Council liaison & design statement | £1,600–£2,400 |
| Planning + Building Regs pack | 14–21 working days | Structural calculations included | £2,200–£3,850 |
Planning Permission across Harrow
Planning Permission in Harrow — FAQs
How long does it take to get planning permission from a London council?+
What happens if the council refuses?+
Do you cover my borough?+
Is the fee really fixed?+
Do I need planning permission for a loft conversion in Harrow?+
What does Harrow expect for a rear extension on a 1930s semi?+
Can I extend a home in Harrow on the Hill or Pinner?+
How long does Harrow Council take to decide?+
How much do planning drawings cost in Harrow?+
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