Loft conversions in Hillingdon
Hillingdon approved 786 of the 931 planning applications for loft conversions it decided in the last five years (84%), and the typical decision took 56 days.
London Borough of Hillingdon · planning applications received Oct 2021 to Oct 2026 · updated 25 Oct 2026
Approved
786 of 931
84% of decided applications; 37 withdrawn, 46 undecided
Typical time to a decision
56 days
median, from 931 decisions with both dates published
Decided within 8 weeks
588 of 931
8 weeks is the usual statutory period; councils can agree extensions
See what was approved near your own address
The The Signal Report shows approvals and refusals for loft conversions within 250 m, 500 m and 1 km of your home, the council's reasons for refusing similar schemes, your property's planning history and the constraints on the plot. Free preview for any address.
Recent decisions
- ApprovedUxbridge
Conversion of roof space to habitable use to include a rear dormer with Juliette balcony, erection of a two storey extension to the rear, a…
2727/APP/2026/1851 · decided 22 Oct 2026
- ApprovedNorthwood
Erection of a double storey rear and side extension, first floor front porch, conversion of roof space to habitable use to include rear dor…
49177/APP/2026/1775 · decided 22 Oct 2026
- Approved51, Uxbridge
Proposed conversion of roof space to habitable use to include a hip to gable extension, rear dormer, gable end window and 3 front roof ligh…
10951/APP/2026/2335 · decided 22 Oct 2026
- RefusedIckenham
Conversion of roof space to habitable use to include rear dormer, front and rear roof lights, conversion of roof from hip to gable end with…
234/APP/2026/1652 · decided 12 Oct 2026
- RefusedRuislip
Erection of part single part two storey side and rear extensions, conversion of garage to habitable use including replacement of the garage…
40031/APP/2026/1530 · decided 9 Oct 2026
Why Hillingdon refuses loft conversions
The council's own words, quoted from recent decision notices.
“1. The proposed ground and first floor front/side extension and hip-to-gable roof conversion, by reason of their overall size, scale, bulk and design, together with the lack of set in from the side boundary and limited setback from the front building line would result in an overly dominant and visually intrusive form of development. The proposal would fail to appear as a subordinate addition to the host dwelling and would be detrimental to its architectural composition and to the character and appearance of the street scene and surrounding area. The development would therefore fail to comply…”
“1. The proposed development, by virtue of its overall size, scale, bulk and design, would result in disproportionate and unsympathetic additions to the property which would fail to appropriately integrate with the existing dwelling. The resultant structure would dominate and unbalance the rear of the dwelling to a significant extent, appearing as visually incongruous and overly-enlarged; failing to integrate successfully with the host dwelling. Considered altogether, the proposal represents an overdevelopment of the site in which the proposed additions considered as a whole are neither subser…”
“1. The proposed extensions by reason of the excessive height and bulk of the roof extensions and siting in this plot would result in a dominant, excessive, visually intrusive, overbearing and incongruous form of overdevelopment that would harm the architectural composition of the plot/site, character and appearance of the Brentford Close as well as Glencoe Road streetscene and visual amenities of the surrounding streetscence. The proposal would therefore be contrary to Policy BE1 of the Hillingdon Local Plan: Part One - Strategic Policies (2012), Policies DMHB 11, DMHB 12 and DMHD 1 of the Hi…”
Other home extensions in Hillingdon
- Single-storey rear extensions
1,395 of 1,564 approved (89%)
- Single-storey side extensions
213 of 251 approved (85%)
- Two-storey and first-floor extensions
618 of 817 approved (76%)
How these figures are made
Planning applications London Borough of Hillingdon received Oct 2021 to Oct 2026, from the council's public planning register as collected by Planning Signal. An application counts as a loft conversion when its own description says so (rules-based classification, tested against blind labelled samples). Duplicate records of one application are counted once. The approval figure counts approved and refused planning applications only: withdrawn and undecided ones, lawful development certificates and prior approvals are left out. Decision times use the received (or validated) date and the decision date the council published.
Past decisions describe what happened to other applications. They are not a prediction for yours: every application is decided on its own design and the council's current policies.