Harrow applies standard suburban householder control across most of HA3, with conservation and green-belt interest toward Harrow Weald Common and Grimsdyke in the north.


If your property sits elsewhere in the borough, the borough-wide page for planning drawings in Harrow covers the same service across every ward.
Planning drawings for Harrow Weald start by establishing whether your scheme is Permitted Development, needs a Lawful Development Certificate, or full planning from Harrow Council. On HA3's inter-war semis and terraces around kenton, wealdstone, the recurring questions are roof additions, rear and side-return extensions, and alterations within Harrow Weald (Grimsdyke / Common fringe). We draw existing and proposed plans, elevations and a site location plan to the council's validation checklist for Kenton, Wealdstone, Harrow Weald, Belmont (Harrow).
Across Kenton, Wealdstone, Harrow Weald, Belmont (Harrow) in HA3, the dominant property is inter-war semis and terraces around kenton, wealdstone and harrow weald, with larger houses toward the green belt. That stock shapes what planning permission drawings looks like here: the right approach for a period terrace differs from a mansion-block flat or a new-build, and Harrow Council judges each on design quality and neighbour impact. We survey the specific Harrow Weald property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the HA3 streetscape.
Housing stock in HA3: Inter-war semis and terraces around Kenton, Wealdstone and Harrow Weald, with larger houses toward the green belt.
Within the district: Kenton, Wealdstone, Harrow Weald, Belmont (Harrow).
Streets we know in HA3: the Kenton estate roads, the streets around Wealdstone and the larger plots toward Harrow Weald Common. Each road has its own building line, boundary treatment and precedent that Harrow Council weighs when assessing a planning permission drawings scheme.
Conservation areas: Harrow Weald (Grimsdyke / Common fringe). Inside these, most external work needs full planning and a Heritage Statement.
Getting around HA3: Kenton, Harrow & Wealdstone and Headstone Lane on the Bakerloo line, Overground and Southern.
Regeneration: Harrow Weald falls within or beside the Wealdstone / Harrow town-centre fringe, which shapes local planning policy and design expectations.
Property values: detached houses are the scarce end of the Harrow market — 175 sold in 2025 at a median of £950,000, against 1,665 sales of all kinds borough-wide at £550,000. HA3's own midpoint, per the Land Registry, was £550,500.
Borough character: Outer north-west London suburban; Harrow on the Hill has exceptionally strict heritage controls; rest of borough permissive.
A chartered technologist visits and laser-measures every room. Typically 60–90 minutes on site.
Drafted in Revit or AutoCAD at 1:100 or 1:50. Fully annotated and council-ready.
Unlimited revisions until you approve. Shadow studies for committee-sensitive applications.
Site location plan, block plan, Design & Access Statement where required.
We lodge the application with Harrow Council and pay statutory fees directly.
Every officer query, consultation response and amendment handled through to determination.
Single planning or building-regs submission.
Planning + building regs + structural.
Listed, conservation or complex sites.

Because HA3 is a settled family market of inter-war semis and terraces around Kenton, Wealdstone and Harrow Weald — ideal for rear and side extensions and hip-to-gable loft conversions. Outside the northern conservation and green-belt fringe, much runs on the Permitted Development route, confirmed with a Lawful Development Certificate.
Toward Harrow Weald Common and Grimsdyke in the north, properties may sit in or near the metropolitan green belt, which tightly limits extending the footprint. We check whether your plot is washed over by green belt before designing; in the built-up area, normal householder and PD rules apply.
Usually yes on the inter-war semis — a hip-to-gable plus rear dormer within the volume allowance, confirmed by a Lawful Development Certificate. We check the head height and any northern conservation constraint, then draw the scheme for Building Control too.
With HA3 houses around £500,000-£825,000 and Bakerloo line and Overground links, a rear extension or loft adds family space worth above the build and drawing cost. HA3 offers strong value across Kenton and Wealdstone.
Harrow Council charges its own statutory application fee (currently £548 for a householder planning application, £610 for a full application). We quote the drawings as one fixed price and the free site survey covers every HA3 address.
For a HA3 project across Kenton, Wealdstone, Harrow Weald, Belmont (Harrow), expect roughly 3–4 weeks from instruction to submission: week 1 the measured survey, weeks 2–3 the drawings and your revisions, then validation and the statutory determination by Harrow Council (8 weeks for a householder application). We carry the Harrow Weald application through every officer query to the decision.
Harrow Weald (HA3) sits primarily in Harrow, so applications are decided by Harrow Council. Conservation areas within HA3 include Harrow Weald (Grimsdyke / Common fringe), where full planning and a Heritage Statement are required. We confirm the planning route for your exact address before quoting.
Almost always. Any structural work behind planning permission drawings in Harrow Weald — new openings, steel beams, loft floors, foundations — needs Building Regulations approval covering structure (Part A), fire escape (Part B) and insulation (Part L), submitted to Harrow Council Building Control or an approved inspector. On HA3's typically terraced and semi-detached stock, a Party Wall notice to adjoining neighbours is normally required before the steelwork. We coordinate both as part of the Complete package.
In value terms, yes. The bigger risk is an unapproved or non-compliant scheme — which is why council-ready drawings and a clean Building Control sign-off matter on HA3 homes.
Planning history and precedent stop at the borough line, so the comparable approvals nearby may sit elsewhere. See all services in HA1, HA2, HA5 and HA7.
Pick a slot that suits you. No obligation and no sales pressure, just straight answers on your planning route.
Every HA3 postcode district we draw in, the stock that dominates it and the authority that validates a planning drawing set there. HA3 fees below are the statutory England rates for 2026, not planning drawing set estimates.
| Postcode | Area | Dominant stock | What it means for a planning drawing set |
|---|---|---|---|
| HA3 | Harrow Weald / Kenton / Wealdstone | 1930s semi-detached | HA3 covers Harrow Weald / Kenton / Wealdstone only; Harrow Council handles the planning drawing set. |
| HA3 | Harrow Weald | 1930s semi-detached | Harrow Weald sits inside HA3; planning drawing set proposals here are determined by Harrow Council. |
| HA3 | Kenton | 1930s semi-detached | Kenton sits inside HA3; planning drawing set proposals here are determined by Harrow Council. |
| HA3 | Wealdstone | 1930s semi-detached, post-war flats | Wealdstone sits inside HA3; planning drawing set proposals here are determined by Harrow Council. |
| HA1 | Harrow / Harrow on the Hill | Georgian and Victorian houses, listed buildings | Adjoining district to HA3, also inside Harrow for planning drawing set purposes. |
| HA2 | North Harrow / South Harrow | 1930s semi-detached | Adjoining district to HA3, also inside Harrow for planning drawing set purposes. |
| HA7 | Stanmore | 1930s semi-detached, Edwardian villas | Adjoining district to HA3, also inside Harrow for planning drawing set purposes. |
Roof pitch, wall build-up and plot depth change every few HA3 streets, and each one changes what a planning drawing set can achieve at that address.
How designation changes a HA3 (Harrow Weald / Kenton / Wealdstone) planning drawing set: Harrow Council maintains 29 conservation areas, including Stanmore, Harrow Weald, Harrow on the Hill. Inside any of them a HA3 (Harrow Weald / Kenton / Wealdstone) planning drawing set cannot rely on permitted development, and the route becomes a £548 householder application determined in 8 weeks rather than a £249 prior approval in 6 weeks. Stanmore sets the tone for HA3 (Harrow Weald / Kenton / Wealdstone) casework.
No blanket Article 4 over HA3 (Harrow Weald / Kenton / Wealdstone): Harrow Council has not withdrawn permitted development across HA3 (Harrow Weald / Kenton / Wealdstone), so a planning drawing set outside a HA3 (Harrow Weald / Kenton / Wealdstone) conservation area usually keeps it. The £274 Lawful Development Certificate is still the document a HA3 owner wants on file.
What HA3 (Harrow Weald / Kenton / Wealdstone) is built from: 1930s semi-detached dominates; Edwardian villas in Harrow on the Hill and Pinner; Metropolitan Green Belt in Stanmore and Harrow Weald; post-war flats around Harrow Central. Outer north-west London suburban; Harrow on the Hill has exceptionally strict heritage controls; rest of borough permissive. That mix decides the planning drawing set route in HA3 (Harrow Weald / Kenton / Wealdstone) more than the postcode does, and it is what a Harrow Council case officer reads first. A householder application costs £548 paid to Harrow Council direct, with 8 weeks to a decision once validated.
Sources for this HA3 planning drawing set page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.
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