House extensions in Hillingdon

Hillingdon received 496 householder applications in the last 12 months - about 10 a week. Rear extensions and dormers are the most common. Of the 44 decided so far, 43 were approved. If you're planning your own, the applications below show what people nearby applied for and how the council decided.

206 last 90 days
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50 last 30 days
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7 last 14 days

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Showing 50 of 206 applications
47583/APP/2026/1641 1 Jul 2026 Undecided

51 EXMOUTH ROAD RUISLIP

Erection of a single storey extension to the rear following the demolition of existing rear conservatory (Application for a Certificate of Lawful Dev...

Hillingdon 1 Jul 2026
13066/APP/2026/1622 30 Jun 2026 Undecided

104 NORTHWOOD ROAD HAREFIELD

Erection of a single storey rear extension, internal alterations, floor plan redesign and all other associated works

Hillingdon 30 Jun 2026
16329/APP/2026/1627 30 Jun 2026 Undecided

10 WESTFIELD WAY RUISLIP

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4.00 metres, for which the maximum height...

Hillingdon 30 Jun 2026
18399/APP/2026/1638 30 Jun 2026 Undecided

Prologis Distribution Park STOCKLEY ROAD WEST DRAYTON UB7 9FN

Internal alterations to an existing building to create a mezzanine and associated staircases (Application for a Certificate of Lawful Development for ...

Hillingdon 30 Jun 2026
80156/APP/2026/1636 30 Jun 2026 Undecided

73 WOODCROFT CRESCENT HILLINGDON UB10 9JD

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4.00 metres, for which the maximum height...

Hillingdon 30 Jun 2026
73204/APP/2026/1548 29 Jun 2026 Undecided

53 ACACIA AVENUE YIEWSLEY UB7 8LW

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4.00 metres, for which the maximum height...

Hillingdon 29 Jun 2026
5107/APP/2026/1612 29 Jun 2026 Undecided

BUSHY LODGE 5 PENNYROYAL DRIVE WEST DRAYTON

Replacement of existing combustible decking boards and decking joists with a non-combustible aluminium decking system (Application for a Certificate o...

Hillingdon 29 Jun 2026
35961/APP/2026/1601 27 Jun 2026 Undecided

11 WHITETHORN AVENUE YIEWSLEY

Erection of a single storey extension to the rear

Hillingdon 27 Jun 2026
73813/APP/2026/1598 26 Jun 2026 Undecided

26 FIR TREE AVENUE WEST DRAYTON UB7 9ET

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4.00 metres, for which the maximum height...

Hillingdon 26 Jun 2026
48861/APP/2026/1574 25 Jun 2026 Undecided

68 HARLYN DRIVE EASTCOTE

Erection of single storey side and rear extension

Hillingdon 25 Jun 2026
9890/APP/2026/1586 25 Jun 2026 Undecided

97 RALEIGH AVENUE HAYES

Erection of outbuilding to rear garden (Application for a Certificate of Lawful Development for a Proposed Development).

Hillingdon 25 Jun 2026
47455/APP/2026/1573 24 Jun 2026 Undecided

47 LADYGATE LANE RUISLIP

Conversion of roof space to habitable use to include hip to gable extension, side dormer and gable end juliette window (Application for a certificate ...

Hillingdon 24 Jun 2026
80149/APP/2026/1572 24 Jun 2026 Undecided

14 LADYGATE LANE RUISLIP HA4 7QU

Erection of single storey wrap around extension, front porch, patio to the rear, amendments to fenestrations and rooflights to the front, side and rea...

Hillingdon 24 Jun 2026
10846/APP/2026/1570 24 Jun 2026 Undecided

5 ASHBURTON ROAD RUISLIP

Amalgamation of two outbuildings to form a single ancillary outbuilding, removal of 5 Ashburton Road rear fencing, including alterations to the reside...

Hillingdon 24 Jun 2026
4996/APP/2026/1576 24 Jun 2026 Undecided

45 OAKLEIGH ROAD UXBRIDGE

Erection of a single storey rear extension, extending from the existing rear extension (Retrospective Application)

Hillingdon 24 Jun 2026
80142/APP/2026/1569 24 Jun 2026 Undecided

20 LAVENDER ROAD UXBRIDGE UB8 3PZ

Conversion of roof space to habitable use to include hip to gable end, rear dormer, 2x rooflights to the front, and extension of rear vent pipe (Appli...

Hillingdon 24 Jun 2026
80152/APP/2026/1581 24 Jun 2026 Undecided

72 BERKELEY CLOSE RUISLIP HA4 6LF

Installation of a dropped kerb

Hillingdon 24 Jun 2026
16823/APP/2026/1563 23 Jun 2026 Undecided

12 NORWICH ROAD NORTHWOOD

Erection of a single storey rear extension, a front porch, application of render to side elevation, and erection of side extension and new roof to out...

Hillingdon 23 Jun 2026
38054/APP/2026/1561 23 Jun 2026 Undecided

33 EAST AVENUE HAYES

Erection of two storey side/rear extension and single storey rear extension to allow conversion of single dwellinghouse into 2no. dwellinghouses with ...

Hillingdon 23 Jun 2026
9490/APP/2026/1564 23 Jun 2026 Undecided

10 MILTON ROAD ICKENHAM

Alterations to external appearance of property including replacement of flat roofs above the first floor side extension and front facing dormer with p...

Hillingdon 23 Jun 2026
47425/APP/2026/1543 22 Jun 2026 Undecided

44 ASH GROVE HAREFIELD

Change of use from Class C3 dwelling to a small House in Multiple Occupation (Class C4) incorporating single-storey rear extension and rear dormer

Hillingdon 22 Jun 2026
15607/APP/2026/1541 22 Jun 2026 Undecided

41 MIDHURST GARDENS UXBRIDGE

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 3.99 metres, for which the maximum height...

Hillingdon 22 Jun 2026
54228/APP/2026/1512 18 Jun 2026 Undecided

46 THE DRIVE ICKENHAM

Erection of part single part double storey front and rear extensions, front porch, windows to side elevation, and roof alterations to include 2 gable ...

Hillingdon 18 Jun 2026
16329/APP/2026/1523 18 Jun 2026 Undecided

10 WESTFIELD WAY RUISLIP

Conversion of roof space to habitable use to include hip to gable extension, rear dormer, gable end window, 2x front roof lights, and an outbuilding t...

Hillingdon 18 Jun 2026
223/APP/2026/1521 18 Jun 2026 Undecided

146 NORTHWOOD ROAD HAREFIELD

Conversion of roof space to habitable use to include rear dormer, enlargement, rear dormer, rooflights to front and top, and the conversion of the int...

Hillingdon 18 Jun 2026
31518/APP/2026/1513 18 Jun 2026 Undecided

3 ELGAR CLOSE ICKENHAM

Conversion of roof space to habitable use to include hip to gable extension, rear dormer, rear extension (Application for a certificate of lawful deve...

Hillingdon 18 Jun 2026
39294/APP/2026/1516 18 Jun 2026 Undecided

12 DAYMER GARDENS EASTCOTE

Erection of double storey rear extension, first storey side extension, front porch, conversion of an integral garage to habitable use, and the install...

Hillingdon 18 Jun 2026
7119/APP/2026/1517 18 Jun 2026 Undecided

31 LIME GROVE RUISLIP

Erection of side extension with a sloped roof, and a front porch, including amendments to fenestrations (Application for a certificate of lawful devel...

Hillingdon 18 Jun 2026
7119/APP/2026/1518 18 Jun 2026 Undecided

31 LIME GROVE RUISLIP

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4 metres, for which the maximum height wo...

Hillingdon 18 Jun 2026
26044/APP/2026/1502 17 Jun 2026 Undecided

8 BERWICK AVENUE HAYES

Conversion of roof space to habitable use to include a rear dormer, hip to gable extension, 2 front roof lights, and a gable end window. (Application ...

Hillingdon 17 Jun 2026
35893/APP/2026/1508 17 Jun 2026 Undecided

64 COPSE WOOD WAY NORTHWOOD

Installation of a dropped kerbs, front boundary wall and associated landscaping

Hillingdon 17 Jun 2026
46380/APP/2026/1493 17 Jun 2026 Undecided

1 WENTWORTH DRIVE EASTCOTE

Erection of a single storey rear extension and demolition of existing conservatory (Application for a Certificate of Lawful Development for a Proposed...

Hillingdon 17 Jun 2026
54228/APP/2026/1511 17 Jun 2026 Undecided

46 THE DRIVE ICKENHAM

Erection of single storey outbuilding to rear garden

Hillingdon 17 Jun 2026
56171/APP/2026/1499 17 Jun 2026 Undecided

10 HAMILTON ROAD HAYES

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4.00 metres, for which the maximum height...

Hillingdon 17 Jun 2026
80132/APP/2026/1491 17 Jun 2026 Undecided

90 WHITETHORN AVENUE YIEWSLEY UB7 8LA

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4.00 metres, for which the maximum height...

Hillingdon 17 Jun 2026
21088/APP/2026/1504 17 Jun 2026 Undecided

28 GROSVENOR AVENUE HAYES

Erection of outbuilding to rear garden (Application for a Certificate of Lawful Development for a Proposed Development).

Hillingdon 17 Jun 2026
26546/APP/2026/1509 17 Jun 2026 Undecided

94 BROADWOOD AVENUE RUISLIP

Conversion of integral garage to habitable use, part utility room to habitable use, erection of a front porch, rear extension and amendments to fenes...

Hillingdon 17 Jun 2026
79837/APP/2026/1490 17 Jun 2026 Undecided

60 BELMORE AVENUE HAYES UB4 0RD

Erection of a part single, part two storey wrap around extension to the front side and rear. Conversion of roof space to habitable use to include a re...

Hillingdon 17 Jun 2026
8029/APP/2026/1495 17 Jun 2026 Undecided

2 ST MARY'S ROAD HAYES

Erection of single storey rear extension

Hillingdon 17 Jun 2026
19954/APP/2026/1479 16 Jun 2026 Undecided

36 WARREN ROAD ICKENHAM

Erection of an outbuilding to the rear garden (Application for a Certificate of Lawful Development for a Proposed Development)

Hillingdon 16 Jun 2026
36674/APP/2026/1482 16 Jun 2026 Undecided

317 LONG DRIVE RUISLIP

Conversion of roof space to habitable use to include a rear dormer with Juliette balcony, roof lights, conversion of roof from hip to gable end with n...

Hillingdon 16 Jun 2026
36674/APP/2026/1485 16 Jun 2026 Undecided

317 LONG DRIVE RUISLIP

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4.00 metres, for which the maximum height...

Hillingdon 16 Jun 2026
50875/APP/2026/1475 16 Jun 2026 Undecided

27 HIGHLAND ROAD NORTHWOOD

Erection of a single storey extension to the rear, erection of porch to the side, following the demolition of existing rear extension (Application for...

Hillingdon 16 Jun 2026
55333/APP/2026/1472 16 Jun 2026 Undecided

30 STAFFORD ROAD RUISLIP MIDDLESEX HA4 6PJ

Conversion of roof space to habitable use to include a rear dormer (Application for a Certificate of Lawful Development for a Proposed Development)

Hillingdon 16 Jun 2026
12176/APP/2026/1474 16 Jun 2026 Undecided

36 KEWFERRY ROAD NORTHWOOD

Raising the existing garage roof in order to facilitate the creation of a shower room.

Hillingdon 16 Jun 2026
5600/APP/2026/1471 15 Jun 2026 Undecided

3 ROYAL LANE UXBRIDGE

Erection of a single storey extension to the side and rear

Hillingdon 15 Jun 2026
80128/APP/2026/1465 15 Jun 2026 Undecided

18 DIAMOND ROAD RUISLIP HA4 0PG

Conversion of roof space to habitable use to include a rear dormer with Juliette balcony, 1 front roof lights and conversion of roof from hip to gable...

Hillingdon 15 Jun 2026
8029/APP/2026/1481 15 Jun 2026 Undecided

2 ST MARY'S ROAD HAYES

Conversion of roof space to habitable use to include a rear dormer, 2 front roof lights, conversion of roof from hip to gable end with new gable end w...

Hillingdon 15 Jun 2026
12087/APP/2026/1461 12 Jun 2026 Pending

21 STANFORD CLOSE RUISLIP

Conversion of roof space to habitable use to include a rear dormer, 2 front roof lights and conversion of roof from hip to gable end with new gable en...

Hillingdon 12 Jun 2026
80129/APP/2026/1467 12 Jun 2026 Pending

2 HOPPNER ROAD HAYES

Erection of a single storey rear extension, which would extend beyond the rear wall of the original house by 4.00 metres, for which the maximum height...

Hillingdon 12 Jun 2026
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Frequently asked questions

When do you need planning permission for a house extension?
Single-storey rear extensions up to 4m (detached) or 3m (semi-detached / terraced) are usually permitted development. Two-storey extensions, anything in a conservation area, or larger projects almost always need a planning application.
What's the difference between planning permission and permitted development?
Permitted development rights let you build certain things without applying for planning permission, subject to specified limits. Anything outside those limits — taller, larger, in a protected area — needs full planning permission.
How long does a householder application take?
The statutory target is 8 weeks from validation. Most simple householder extensions are decided within that window; complex or contested cases (especially with objections) can take longer.
Can I get email alerts for new extensions applications in Hillingdon?
Yes. Click "Set up alerts" on this page and you'll get a daily or weekly email listing every new extensions application published by Hillingdon. You can also narrow the alert to a postcode, street, or drawn area.

We check Hillingdon's planning portal daily. New extensions applications appear here within a day of being published.