Planning Permission in Hillingdon

The London Borough of Hillingdon is one of West London’s most suburban, spacious, and diverse boroughs. With its generous plots, leafy neighbourhoods, and distinctive architectural character, Hillingdon offers homeowners excellent opportunities to extend, modernise, and reconfigure their homes. From the conservation areas of Ruislip, Harefield, and Uxbridge to the suburban communities of Hayes, Ickenham, Hillingdon Village, West Drayton, and Northwood, the borough blends heritage charm with modern suburban living. However, Hillingdon also has a clear and structured planning framework, meaning proposals must be carefully prepared to meet the council’s expectations around design, neighbour amenity, and character preservation.
Whether you’re planning a rear extension, loft conversion, garage conversion, outbuilding, or internal reconfiguration, Hillingdon requires proposals to be well designed, policy aligned, and sensitive to the borough’s suburban and heritage context.
Understanding Hillingdon’s Planning Environment
Hillingdon is known for its strong emphasis on suburban character, neighbour amenity, and high quality design. The borough contains several conservation areas, including Ruislip Village, Harefield Village, Uxbridge Common, and parts of Northwood. These areas are protected for their architectural and historic significance, meaning external alterations must preserve or enhance local character. Proposals affecting listed buildings or heritage streetscapes require careful justification and may need heritage statements.
Neighbour amenity is a major consideration in Hillingdon. Extensions must be designed to avoid harming daylight, sunlight, privacy, or the sense of openness enjoyed by neighbouring properties. The council uses clear amenity tests, including the 45 degree and 25 degree rules, to assess the impact of extensions on neighbouring windows and gardens. Even modest proposals may require detailed analysis, especially in semi detached or terraced streets.
Hillingdon is particularly known for its structured approach to rear extensions, loft conversions, and outbuildings. Rear extensions — including wrap arounds and side returns — are common but must respect scale, materials, and the character of the host property. Loft conversions are widely accepted when designed sensitively, with dormers kept subordinate to the main roof. Roof terraces are especially sensitive due to privacy concerns.
Large parts of Hillingdon fall within the Metropolitan Green Belt, especially around Harefield, Ruislip, and Northwood. Properties in these areas face stricter controls on extensions, outbuildings, and changes of use. Demonstrating that proposals do not harm openness is essential.
Flood risk is a consideration in areas near the River Colne, Frays River, and parts of West Drayton and Yiewsley. Properties in these zones may require flood risk assessments or resilient design measures.
Sustainability is another key priority. Hillingdon encourages energy efficient design, sustainable materials, and proposals that reduce carbon impact. This can influence glazing choices, insulation, and the overall design approach.

What SMARTePLANS Provides

SMARTePLANS offers a comprehensive planning service tailored to Hillingdon’s clear but detail oriented planning environment. Our expertise ensures your proposal is robust, policy aligned, and positioned for approval.
• Detailed Planning Drawings
We produce precise architectural drawings for extensions, loft conversions, internal alterations, and façade changes. Our designs respect Hillingdon’s character while maximising your space.
• 3D Laser Surveys & Modelling
Accurate measurement is essential for high quality design. Our 3D surveys capture every detail, enabling us to produce highly accurate plans and visualisations.
• Design & Access Statements
We prepare clear, persuasive statements that explain the design rationale, demonstrate policy compliance, and address Hillingdon’s key concerns.
• Heritage & Conservation Expertise
For properties in conservation areas or listed buildings, we prepare sensitive, policy compliant designs supported by heritage statements where necessary.
• Green Belt Guidance
For properties in protected land, we provide strategic advice to maximise approval potential.
• Daylight/Sunlight Analysis
Where required, we arrange specialist assessments to support your application and address neighbour amenity considerations.
• Flood Risk & Environmental Documentation
For properties near rivers or low lying areas, we coordinate flood risk assessments and resilient design measures.
• Planning Agent Representation
We manage the entire process — liaising with planning officers, responding to queries, and ensuring your application is complete and professionally presented.

Key Local Planning Considerations in Hillingdon

1. Conservation Areas
Proposals must preserve or enhance local character, affecting:
• Rooflines
• Windows and doors
• Materials
• Extensions
• Boundary treatments
2. Green Belt Controls
Properties in the Green Belt face stricter controls on:
• Extensions
• Outbuildings
• Height and massing
• Changes of use
3. Neighbour Amenity
Extensions must demonstrate minimal impact on:
• Daylight
• Sunlight
• Privacy
• Sense of enclosure
4. Loft Conversions & Roof Alterations
Dormers must be modest, well integrated, and subordinate to the main roof.
5. Flood Risk
Properties near rivers or low lying areas may require flood risk assessments.

Why Choose SMARTePLANS for Hillingdon Applications

SMARTePLANS has extensive experience working within Hillingdon’s planning framework. Our 99% approval rate reflects our commitment to policy led design, meticulous preparation, and proactive communication with planning officers.

Homeowners choose us because:

• We understand Hillingdon’s unique suburban and heritage constraints
• We produce high quality, policy aligned designs
• We manage the entire process from survey to submission
• We specialise in extensions, loft conversions, and Green Belt proposals
• We deliver fast turnaround times without compromising quality
Whether you’re planning an extension, loft conversion, internal reconfiguration, or a more complex redevelopment, we ensure your application is robust, compliant, and positioned for approval.

Start Your Hillingdon Planning Application Today

SMARTePLANS offers a free, no obligation quote and expert guidance tailored to your property. Our team handles everything — from surveys to submission — so you can move forward with confidence.