Hillingdon Planning Committee has approved a single-storey rear extension and loft conversion at 74 St George's Drive, Ickenham, despite objections from local residents. The decision, made on Thursday, June 4, 2026, allows for alterations to the garage roof, conversion of the main roof to habitable accommodation with dormers and a hip-to-gable extension, demolition of a chimney, and expansion of a raised patio area.
The application was called to committee due to a petition with 181 signatures, raising concerns about neighbour amenity, the character of the area, overdevelopment, flood risk, and the retrospective nature of some works.
Officers noted that materially similar extensions had previously been granted under Permitted Development rights. However, the current proposal includes several deviations that exceed the permitted development threshold and thus require planning permission. These alterations include the enlargement of the west-facing dormer to match the box design of the east-facing dormer, rear dormers that are no longer set in from the gable edge and include an additional window, and an increased height of the rear extension by approximately 0.25m. Furthermore, the proposed raised patio and garage roof alterations are new to this application. Despite these deviations, officers considered the current proposal's changes to be acceptable.
Residents raised concerns about neighbour amenity, specifically citing potential loss of privacy, loss of daylight/overshadowing, and non-compliance with the 45-degree test. The officer's report addressed these concerns by assessing the proposal against relevant policies and considering the fallback position of previously granted Permitted Development rights. The report concluded that while some change to neighbour amenity is acknowledged, the impacts are not considered to give rise to material harm that would justify a refusal when assessed against the development plan as a whole, especially when considering what could reasonably be implemented under existing permissions.
Regarding flood risk, the site is located in Flood Zone 1, where the risk of fluvial flooding is low and residential development is considered appropriate. The proposal, which involves the erection of two detached dwellings, results in an increase in hardstanding but is not considered to materially alter the existing surface-water runoff characteristics of the plot. A condition has been added requiring sustainable water management details for the site to be submitted and approved, ensuring appropriate drainage for the new dwellings.
Residents also raised concerns about 'overdevelopment of a constrained site and disproportionate to other houses in the Close'. While the officer's report addressed this by discussing the proposal in relation to planning policies and design, a specific definition of 'overdevelopment' and the precise criteria used to determine it did not constitute it for this application were not explicitly detailed beyond the general assessment against planning policies.
Conditions have been imposed to regularise existing unlawful works and ensure necessary alterations are completed within a six-month timeframe. Specifically, the rear patio, which exceeds the approved 0.3m height, and the west-facing dormer, which differs from what has been built and does not comply with permitted development rules, are identified as unlawful aspects. The property owner must either alter these elements to comply with the approved plans or demolish them within six months of the decision. The retrospective nature of the application, described as (Part Retrospective)
, is not a planning consideration in itself. Construction had commenced following previous approvals, but the development was not carried out in accordance with those plans. The planning system does not operate punitively, and the retrospective nature means the proposal is assessed on its planning merits, with a condition requiring rectification or demolition of non-compliant works.
The approval includes conditions for obscure glazing to flank elevation windows. The purpose of this condition, as stated in the reason for the condition, is To prevent overlooking to adjoining properties in accordance with policies DMHB 11 and DMHD 1-2 of the Hillingdon Local Plan Part 2 (2020).
For flank windows, these are to be obscure glazed and non-openable below 1.8m.
While the report mentions that the site has already had a Certificate of Lawfulness and prior approval for a rear hip-to-gable extension and side dormers, and a single-storey rear extension, exact dimensions and specifications of the approved dormers and hip-to-gable extension compared to the existing structure are not fully detailed in a comparative manner within the provided information. The report does, however, detail the amendments made to the application, which include the enlargement of the west-facing dormer, rear dormers no longer set in from the gable edge and including an additional window, and an increased height of the rear extension by approximately 0.25m.
Public reports pack 04th-Jun-2026 19.00 Hillingdon Planning Committee.pdf
