TL;DR — Key Facts
- Planning authority: Hillingdon Council
- Conservation areas: 29 designated areas
- Article 4 Directions: None currently in force
- Postcodes covered: HA4, HA5, HA6, UB3, UB4, UB7, UB8, UB9, UB10, UB11
- Typical housing: 1930s semi-detached dominates
- Householder application fee: £258 (2026 rate)
Planning in Hillingdon — what you need to know
If you are planning a home improvement project in Hillingdon, understanding the local planning landscape is essential before you begin. Hillingdon is managed by London Borough of Hillingdon, which handles all planning applications, enforcement, and local plan policy for the borough.
Largest outer west London borough; significant Green Belt; Heathrow noise contours affect planning decisions in Harmondsworth and Sipson. The borough has a population of approximately 306,000 residents and covers postcodes HA4, HA5, HA6, UB3, UB4, UB7, UB8, UB9, UB10, UB11.
The housing stock in Hillingdon is predominantly 1930s semi-detached dominates; Metropolitan Green Belt covers much of north Hillingdon; Victorian cottages in Uxbridge and Ruislip villages; post-war housing near Heathrow. This mix of property types means that Hillingdon Council deals with a wide range of applications, from rear extensions on terraced houses to loft conversions on semi-detached properties and full refurbishments of period homes in conservation areas.
With 29 designated conservation areas and no current Article 4 Directions, Hillingdon has a planning environment that balances heritage protection in conservation areas with generally permissive policies elsewhere.
At Architectural Drawings London, we prepare planning drawings and building regulations drawings for properties across all Hillingdon postcodes. Our MCIAT chartered architectural technologists have experience with Hillingdon Council and understand the specific policies, design guides, and precedents that apply in Hillingdon. Our fixed fees start from £840 for our Essentials package and £1,750 for our Complete package — 30% below typical London architect rates.
Article 4 Directions in Hillingdon
Hillingdon does not currently have any borough-wide Article 4 Directions that restrict Permitted Development rights for standard householder developments such as loft conversions, rear extensions, or outbuildings.
This means that most common home improvements in Hillingdon can proceed under Permitted Development without needing to apply for planning permission, provided they meet the national criteria for size, height, and position. We recommend applying for a Lawful Development Certificate (£129) to formally confirm that your project qualifies as Permitted Development. This provides legal certainty and is valuable when selling the property.
Even without Article 4 Directions, properties in Hillingdon's 29 conservation areas have additional restrictions on permitted development. We check the specific restrictions affecting your property as part of our initial assessment.
Conservation areas in Hillingdon
Hillingdon has 29 designated conservation areas. Notable conservation areas include:
- Uxbridge
- Ruislip Village
- Northwood
- Harefield
- Ickenham
In conservation areas, Permitted Development rights are more restricted than in non-designated areas. Key restrictions include:
- No cladding, stone, artificial stone, pebble dash, render, timber, plastic, or tile to any external wall without planning permission
- No side extensions under Permitted Development
- Rear extensions are limited and may require planning permission
- Dormer loft conversions facing the highway require planning permission
- Satellite dishes on front elevations or chimneys are not permitted
- Demolition of gates, walls, fences, or other boundary treatment requires planning permission
If your property is in a Hillingdon conservation area, we can advise on what is achievable and prepare a planning application that addresses the conservation officer's requirements. Our 98% first-time approval rate includes a strong record in conservation area applications.
Popular projects in Hillingdon
The types of planning applications most commonly submitted in Hillingdon are shaped by the borough's housing stock. 1930s semi-detached dominates; Metropolitan Green Belt covers much of north Hillingdon; Victorian cottages in Uxbridge and Ruislip villages; post-war housing near Heathrow, which drives demand for specific types of extensions and conversions.
Two-storey extensions
The semi-detached and detached housing stock in Hillingdon is well suited to two-storey rear extensions, which almost always require planning permission. A two-storey extension can add a larger kitchen-diner at ground floor and an additional bedroom and bathroom above. Hillingdon Council generally supports two-storey extensions that are subordinate to the original dwelling, set in from the boundary, and do not result in unacceptable loss of light or privacy to neighbours. Our Complete package from £1,750 covers full planning and building regulations drawings.
How much do planning drawings cost in Hillingdon?
The cost of a planning application in Hillingdon has two components: the council application fee and the professional drawing fees.
Planning costs in Hillingdon
Our fixed-fee pricing means you know the cost upfront with no hourly billing surprises. We include a measured survey, existing and proposed plans, elevations, and a site plan — everything required for a valid planning submission to Hillingdon Council. Our fees are 30% below typical London architect rates for the same scope of work.
For Permitted Development projects that do not require a planning application, we recommend obtaining a Lawful Development Certificate (£129 council fee). This provides formal legal confirmation that your project is lawful and prevents problems when selling the property. We prepare the LDC drawings and application on your behalf.
Our experience in Hillingdon
We cover all Hillingdon postcodes: HA4, HA5, HA6, UB3, UB4, UB7, UB8, UB9, UB10, UB11. Whether your property is in a conservation area, affected by an Article 4 Direction, or in an unrestricted residential street, we have experience with Hillingdon Council and understand the borough's planning policies.
Our MCIAT chartered architectural technologists prepare planning drawings and building regulations drawings for residential projects across Hillingdon. We handle the full process from initial measured survey through to planning submission, and we liaise with Hillingdon Council on your behalf.
We also work in Hillingdon's neighbouring boroughs:
Frequently asked questions
Do I need planning permission in Hillingdon?
Many home improvements in Hillingdon fall under Permitted Development (PD) rights and do not need planning permission. This includes single-storey rear extensions up to 6 metres, most rear dormer loft conversions, and internal alterations. However, if your property is in one of Hillingdon's 29 conservation areas, PD rights may be restricted and full planning permission may be required. We recommend checking with Hillingdon Council or applying for a Lawful Development Certificate.
Does Hillingdon have Article 4 Directions?
No. Hillingdon does not currently have any borough-wide Article 4 Directions that remove Permitted Development rights for residential householder developments. However, individual properties may still have conditions or restrictions, and conservation area rules apply separately.
How many conservation areas are in Hillingdon?
Hillingdon has 29 designated conservation areas, including Uxbridge, Ruislip Village, Northwood, Harefield, Ickenham. In conservation areas, Permitted Development rights are more restricted. For example, you cannot add cladding, build side extensions, or install satellite dishes without planning permission. Rear extensions and loft conversions may also be restricted. Always check whether your property falls within a conservation area before starting work.
How much does a London Borough of Hillingdon planning application cost?
A householder planning application to London Borough of Hillingdon costs £258 (2026 rate). On top of the council fee, you need professional architectural drawings. At Architectural Drawings London, our Essentials package starts from £840 and our Complete package from £1,750, making a typical total cost between £1,098 and £2,008. A Lawful Development Certificate (for Permitted Development confirmation) costs £129.
How long does London Borough of Hillingdon take to decide a planning application?
The statutory target for a householder planning application is 8 weeks. In practice, Hillingdon Council may take longer during busy periods. Pre-application advice typically takes 4-6 weeks. From initial instruction to final decision, expect 12-16 weeks for a straightforward householder application in Hillingdon. Major applications have a 13-week determination period.