House extensions in Harrow

Harrow received 891 householder applications in the last 12 months - about 17 a week. Rear extensions and dormers are the most common. Of the 218 decided so far, 166 were approved. If you're planning your own, the applications below show what people nearby applied for and how the council decided.

519 last 90 days
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165 last 30 days
|
75 last 14 days

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Showing 50 of 519 applications
PL/1868/26 Yesterday Pending

62 Chandos Crescent, Edgware, Harrow, HA8 6HL

Single storey rear extension: 4.00 metres deep, 3.00 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow
PL/1855/26 Yesterday Pending

100 Camrose Avenue, Edgware, Harrow, HA8 6ET

Certificate of lawful development (proposed): Alterations to roof to form end gable and rear dormer; installation of two front rooflights; front porch

Certificate of Lawful Development Proposed Harrow
PL/1853/26 Yesterday Pending

1 Lansdowne Road, Stanmore, Harrow, HA7 2RX

Front porch; Single storey side to rear extension; Alterations to roof of front extension; External alterations 1m high boundary wall to front and sid...

Householder Harrow
PL/1842/26 Yesterday Pending

18 Winchester Road, Kenton, Harrow, HA3 9PE

Single storey side extension

Householder Harrow
PL/1836/26 Yesterday Pending

35 West Drive, Harrow Weald, Harrow, HA3 6TX

Single storey rear extension (Demolition of rear extension)

Householder Harrow
PL/1719/26 Yesterday Pending

7 Elm Grove, Rayners Lane, Harrow, HA2 7JE

Single storey rear extension; conversion of garage into habitable room with installation of window to front; front porch; external alterations (demoli...

Householder Harrow
PL/1715/26 Yesterday Pending

43 Hawthorn Drive, North Harrow, Harrow, HA2 7NU

Single storey rear extension; rear decking

Householder Harrow
PL/1712/26 Yesterday Pending

3 Headstone Gardens, Harrow, HA2 6PH

Single storey front extension incorporating front porch; conversion of garage to habitable room; external alteration

Householder Harrow
PL/1695/26 Yesterday Pending

346 Pinner Road, North Harrow, Harrow

Part change of use of studio flat (C3) to extend retail unit (Class E) on ground floor; single, two and three storey rear extensions to create three f...

Full Planning Application Harrow
PL/1692/26 Yesterday Pending

178 Camrose Avenue, Edgware, Harrow, HA8 6BU

Conversion of garage to habitable room; external alteration

Householder Harrow
PL/1689/26 Yesterday Pending

19 Argyle Road, North Harrow, Harrow, HA2 7AL

Certificate Of Lawful Development (Proposed): Alterations and extension to roof to form end gable; rear dormer; three rooflights in front roof slope

Certificate of Lawful Development Proposed Harrow
PL/1685/26 Yesterday Pending

OAKRIDGE Nugents Park, Hatch End, Pinner, Harrow, HA5 4RA

Single and two storey front extensions incorporating front porch; two storey rear extension; rear dormer; three rooflights in front roof slope; detach...

Householder Harrow
PL/1668/26 Yesterday Pending

112 Weald Lane, Harrow Weald, Harrow, HA3 5EZ

Single story rear extension with pitched roof (Part retrospective)

Householder Harrow
PL/1851/26 2 days ago Pending

100 Camrose Avenue, Edgware, Harrow, HA8 6ET

Single storey rear extension: 4.00 metres deep, 3.20 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow
PL/1781/26 2 days ago Pending

8 Northumberland Road, North Harrow, Harrow, HA2 7RD

Single storey rear extension: 6.00 metres deep, 3.00 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow
PL/1858/26 2 days ago Pending

24 Reynolds Drive, Edgware, Harrow, HA8 5PZ

Single storey rear extension: 6.00 metres deep, 3.20 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow
PL/1844/26 9 Jul 2026 Pending

21 Pinner Park Gardens, Harrow, HA2 6LQ

Single storey rear extension: 6.00 metres deep, 3.20 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow 9 Jul 2026
PL/1834/26 9 Jul 2026 Pending

40 Rusland Park Road, Harrow, HA1 1UT

Replacement of detached garage; boundary treatment including installation of 2m high timber fence and vehicle entrance gates

Householder Harrow 9 Jul 2026
PL/1287/26 9 Jul 2026 Pending

10 Beechen Grove, Pinner, Harrow, HA5 3AH

Single storey front extension; conversion of garage to habitable room; single and two storey rear extension

Householder Harrow 9 Jul 2026
PL/1219/26 9 Jul 2026 Pending

27 Mepham Gardens, Harrow Weald, Harrow, HA3 6QS

Three storey side extension to create new dwelling with private amenity space and associated landscaping; Cycle and refuse storage

Full Planning Application Harrow 9 Jul 2026
PL/1841/26 9 Jul 2026 Pending

7 Bridgewater Gardens, Edgware, Harrow, HA8 6AP

Certificate of Lawful Development (Proposed): Alterations and extension to roof to form end gable; rear dormer; two rooflights in front roof slope; wi...

Certificate of Lawful Development Proposed Harrow 9 Jul 2026
PL/1817/26 8 Jul 2026 Pending

3 Dennis Lane, Stanmore, Harrow, HA7 4JR

Replace fencing with wire netting and angled supports over with new low rendered block wall and fence panels

Householder Harrow 8 Jul 2026
PL/1720/26 8 Jul 2026 Pending

26 Tonbridge Crescent, Kenton, Harrow, HA3 9LA

Two storey side extension; single and two storey rear extension; attached single-storey outbuilding at side for use as a boiler room (part retrospecti...

Householder Harrow 8 Jul 2026
PL/1805/26 8 Jul 2026 Pending

44 Warrington Road, Harrow, HA1 1SY

Single storey side extension (demolition of lean to)

Householder Harrow 8 Jul 2026
PL/1820/26 7 Jul 2026 Pending

121 Carmelite Road, Harrow Weald, Harrow, HA3 5LU

First floor rear extension; Juliette balcony; external alterations

Householder Harrow 7 Jul 2026
PL/1815/26 7 Jul 2026 Pending

56 Silverston Way, Stanmore, Harrow, HA7 4HR

Single storey rear extension: 6.00 metres deep, 3.60 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow 7 Jul 2026
PL/1808/26 7 Jul 2026 Pending

6 Old Lodge Way, Stanmore, Harrow, HA7 3AR

Conversion of garage to habitable room; Installation of window in front elevation; External alterations (Partial demolition of garage)

Householder Harrow 7 Jul 2026
PL/1803/26 7 Jul 2026 Pending

23 Warden Avenue, Rayners Lane, Harrow, HA2 9LP

Certificate of Lawful Existing Development: Single storey rear extension, Steps to rear (Demolition of patio and steps to rear)

Certificate of Lawful Development Existing Harrow 7 Jul 2026
PL/1796/26 7 Jul 2026 Pending

17 Somervell Road, South Harrow, Harrow, HA2 8TY

Certificate of Lawful Proposed Development: Alterations to roof to form end gable and rear dormer; Installation of two roof lights in front roof slope...

Certificate of Lawful Development Proposed Harrow 7 Jul 2026
PL/1790/26 7 Jul 2026 Pending

16 Hawthorne Avenue, Kenton, Harrow, HA3 8AG

Certificate of Lawful Proposed Development: Alterations to roof to form end gable and rear dormer; Installation of three roof lights in front roof slo...

Certificate of Lawful Development Proposed Harrow 7 Jul 2026
PL/1814/26 7 Jul 2026 Pending

111 Mollison Way, Edgware, Harrow, HA8 5QU

Single storey rear extension: 6.00 metres deep, 3.85 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow 7 Jul 2026
PL/1809/26 7 Jul 2026 Pending

28 Elmwood Avenue, Kenton, Harrow, HA3 8AH

Single storey rear extension with external steps; alterations to roof; rear dormer; external alterations

Householder Harrow 7 Jul 2026
PL/1798/26 7 Jul 2026 Pending

22 Eastern Avenue, Rayners Lane, Pinner, Harrow, HA5 1NP

Single and two storey side to rear extension; single storey rear extension; change of use: dwelling (C3) to a six room, six person HMO (C4)

Full Planning Application Harrow 7 Jul 2026
PL/1783/26 7 Jul 2026 Pending

Rear Of 380 Northolt Road Rear Of 380 Northolt Road, Harrow, HA2 8ES

Installation of window on frank wall; removal of roller shutter; external alterations (retrospective)

Full Planning Application Harrow 7 Jul 2026
PL/1804/26 7 Jul 2026 Pending

28 Grange Gardens, Pinner, Harrow, HA5 5QE

Single and two storey side to rear extension; single storey rear extension; external alterations extension of raised deck area by 1.2m into the garden...

Householder Harrow 7 Jul 2026
PL/1802/26 7 Jul 2026 Pending

82 Abercorn Crescent, South Harrow, Harrow, HA2 0PU

Single storey rear extension: 6.00 metres deep, 3.49 metres maximum height and 2.62 metres high to the eaves

Prior Notification - Larger Home Extension Harrow 7 Jul 2026
PL/1794/26 4 Jul 2026 Pending

65 Dean Drive, Edgware, Stanmore, Harrow, HA7 1HB

Single storey rear extension: 5.00 metres deep, 3.00 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow 4 Jul 2026
PL/1797/26 4 Jul 2026 Pending

61 Uppingham Avenue, Stanmore, Harrow, HA7 2JB

Single storey rear extension: 6.00 metres deep, 3.40 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow 4 Jul 2026
PL/1793/26 4 Jul 2026 Pending

36 Hinkler Road, Kenton, Harrow, HA3 9AU

Single storey rear extension: 6.00 metres deep, 3.38 metres maximum height and 2.75 metres high to the eaves

Prior Notification - Larger Home Extension Harrow 4 Jul 2026
PL/1248/26 4 Jul 2026 Pending

1 Astwood Drive, Harrow, Stanmore, HA7 3FR

Creation of first floor within roof of detached garage for use as gym; window to front; two side dormers; roof light to side roof slope (Demolition of...

Householder Harrow 4 Jul 2026
PL/1537/26 4 Jul 2026 Pending

37 Moorhouse Road, Kenton, Harrow, HA3 9JD

Single and two storey side to rear extension; roof light in front roof slope; external alterations

Householder Harrow 4 Jul 2026
PL/1661/26 4 Jul 2026 Pending

18 Carmelite Road, Harrow Weald, Harrow, HA3 5LR

Conversion of dwellinghouse into two flats (1 x 3 bed and 1 x 1 bed); single storey front extension incorporating front porch; single storey side to r...

Full Planning Application Harrow 4 Jul 2026
PL/1625/26 4 Jul 2026 Pending

99 Axholme Avenue, Edgware, Harrow, HA8 5BD

Alterations and extension to roof to form end gable; rear dormer with Juliet balcony; window in end gable; two rooflights in front roof slope

Householder Harrow 4 Jul 2026
PL/1613/26 4 Jul 2026 Pending

4 North Way, Pinner, Harrow, HA5 3NY

Front porch; single and two storey rear extension; rear dormer; roof lights in roof slopes

Householder Harrow 4 Jul 2026
PL/1786/26 3 Jul 2026 Pending

23 Stuart Road, Wealdstone, Harrow, HA3 7RB

Conversion of detached garage at rear to provide a single storey dwelling house ( 1 x 1 bed); Replace garage doors with door and window in front eleva...

Full Planning Application Harrow 3 Jul 2026
PL/1766/26 3 Jul 2026 Pending

17 Sandymount Avenue, Stanmore, Harrow, HA7 4UA

Vehicle access

Householder Harrow 3 Jul 2026
PL/1680/26 3 Jul 2026 Pending

232 Northolt Road, South Harrow, Harrow, HA2 8DU

Demolition of existing rear timber structure and erection of a single-storey rear extension; subdivision of the rear extension to form three additiona...

Full Planning Application Harrow 3 Jul 2026
PL/1395/26 3 Jul 2026 Pending

WOODLAND HALL NURSING HOME Clamp Hill, Harrow Weald, Stanmore, Harrow, HA7 3BG

Installation of 1.5m high boundary railings to front and side

Full Planning Application Harrow 3 Jul 2026
PL/1792/26 3 Jul 2026 Pending

3 Monro Gardens, Harrow Weald, Harrow, HA3 6HH

Single storey rear extension: 6.50 metres deep, 3.20 metres maximum height and 3.00 metres high to the eaves

Prior Notification - Larger Home Extension Harrow 3 Jul 2026
PL/1791/26 3 Jul 2026 Pending

MELTON HOUSE Sudbury Hill, Sudbury, Harrow, HA1 3ND

Single storey rear glazed extension; single storey side extension; installation of additional windows to front elevation at first floor level; externa...

Householder Harrow 3 Jul 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 Harrow?
Yes. Click "Set up alerts" on this page and you'll get a daily or weekly email listing every new extensions application published by Harrow. You can also narrow the alert to a postcode, street, or drawn area.

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