Side Extension planning permission examples — what gets approved & refused
183,776 real decisions from 277 UK councils. See what actually gets approved, what gets refused, and why — so you don’t waste thousands on drawings for something your council will reject.
Last updated: September 2026
Category-level approval rates for these examples are currently withheld while we re-check how decisions are sorted into project types. Each decision below is a real record from the council’s own planning portal and links to it. Council-level approval rates are unaffected and remain on the council pages.
That means roughly 1 in 7 side extension applications are refused — often due to avoidable design issues.
183,776
Decisions
156,337
Approved
27,439
Refused
277
Councils
Side extensions make use of often-wasted space alongside the house. Side return extensions in terraced houses are particularly popular in urban areas.
What these results show
⚠️ These are national examples. Your council could be stricter — or more lenient. See what actually gets approved on your street →
Real side extension decisions
Real examples showing what works — and what gets refused. Use the filters to compare approved and refused applications.
Approved
Non-material amendment to planning permission 24/P/00345 approved 24/04/2024 for the 'Erection of single storey side and rear extensions together with habitable rooms in new roofspace, following demolition of existing garage and rear extension' to changes to the approved drawings for the installatio
09/00398/LBCCA
Approved
Remove existing asbestos roof from side extension and replace with new plywood boarding and Caithness Slate, refit existing rhones and downpipes fit new lead flashing at junction with main house, fit velux roof window
Approved
Prior Notification under Schedule 2 Part 11 Class B of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended) for demolition of existing former Medina Dairy site walls, including roller shutter doors, and roof of pitched roof, single storey frontage building,
25/00027/OBS
Approved
Consultation by London Borough of Southwark on a request for an EIA Screening Opinion for the redevelopment of the site including partial demolition, extension and renewal of the existing office building to provide additional high quality office space, the redevelopment of Keats House with the reten
Approved
Certificate of Lawful Use (Proposed): Erect a single-storey side extension to existing dwelling and replace existing garage roof (to enable conversion of garage to form additional living accommodation)
Approved
Demolition of the existing front uPVC porch and side timber sunroom and construction of a single-storey front and side extension with rear terrace, together with associated landscaping and alterations to external fenestration
22/01051/NMA
Approved
Non material amendment sought to approved two storey side extension under planning permission ref 21/01590/FUL for 2 additional windows and changing pitched roof to flat roof
Refused
NON MATERIAL AMENDMENT TO APPLICATION 2021/0496/HHA (TWO STOREY SIDE EXTENSION) - FOR REMOVAL OF REAR GARAGE PITCHED ROOF AND REPLACE WITH FLAT ROOF. CHANGE OF REAR BEDROOM WINDOW TO JULIET BALCONY. REMOVAL OF PROPOSED FLAT SECTION OF APPROVED SCHEME AND INSTALLATION OF PITCHED ROOF AND INCREASE IN
Approved
Single Storey Side Extension to Form Garage, En-suite Bedroom and Boot Room, Removal of Loadbearing Walls Between Kitchen/Dining/New Snug, Alterations at First Floor Level to Form Enlarged Master Bedroom/ En-suite/Dressing Room and Formation of Dormer to Rear
Approved
Application for prior approval for erection of two single storey rear extensions and one single storey side extension that projects more than 4m but less than 8m beyond the rear elevation
Approved
Prior notification for a single storey side and rear extension measuring 4.3m in
Approved
Certificate of Lawful Use for Single Storey Pitched Roof Side Extension
Approved
The construction of a single-storey rear side return extension, roof extension to the rear roof slope, installation of 2 roof lights to front roof slope, replacement of existing rear-facing shared roof light and a first-floor window and all associated works at 49b Merritt Road SE4.
Refused
Replacement of existing mono-pitch garage area to provide new 2-storey side extension with garage/utility/bedroom accommodation with additional single-storey extension to rear
Refused
Erection of two storey side and rear extensions to form porch, shower room, kitchen & utility on ground floor, and new bedroom, bathroom & study on first floor
Refused
Non-material amendment to planning approval 22/01541/PLF - amendments including external insulation and render to external walls, replacement roof to existing side extension, new rooflight to rear elevation and omission of rooflight to front elevation
Approved
Erect single storey side extension, increase height of roof to form habitable accommodation and erect dormer windows to side (amended proposal)
Approved
Erection of a single storey side extension, re-cladding/roofing of existing box dormer addition of porch and remodelling of rear bay, Byways, North Bovey.
Approved
Details of condition 2 (external materials) of existing application 2023/1426 (Demolition of existing garages and erection of new, side extension and addition of dormer windows in existing roof) dated 26/07/2023
Approved
Demolition of rear single storey buildings and erection of single storey side/rear extension, widening of existing front access with provision of new ramp and new glazed doors, creation of new accesses off Cecil Street including works to existing pillars and railings. Installation of polycarbonate p
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Approved
Details of condition 2 (external materials) of existing application 2023/1426 (Demolition of existing garages and erection of new, side extension and addition of dormer windows in existing roof) dated 26/07/2023
Approved
Double storey side extension, single storey rear extension and rear roof dormer extension.
Approved
Certificate Of Lawful Development For The Erection Of Single Storey Side Extension And Detached Triple Garage, Workshop And Stores.
Approved
Erect extension to rear of property. Demolish existing adjoining side garage and replace with full height side extension. Erect one and half storey garage for campervan, storage and upper workshop.
Approved
Erection of a single storey side and rear extension with attached single storey garage following demolition of the existing detached garage.
Approved
Erection of single storey rear extension, two storey side extension and alteration to existing garage roof to facilitate additional utility space.
Approved
Erection of a single storey side extension to a Grade II listed building
Approved
Demolish existing side and rear extensions. Construct new 1.5 storey side extension and single storey porch extensions to front and rear.
Approved
Non material amendment of planning application P/25/0076 to include a roof light in the front roof slope of the two storey side extension
Approved
Application for Lawful Development Certificate for Proposed Use or Development for Proposed single storey side extension to existing dwelling.
Refused
Single storey side infill extension and demolition of existing conservatory. Enlargement of an existing first floor rear window.
Refused
Change of use from single family dwelling to a house of multiple occuption and proposed 2 storey rear and side extension to provide 6 bedrooms overall for proposed HMO (Amended Description)
Refused
Two Storey Side Extension To Provide Garage, WC & Dining Room On Ground Floor With 2No. Bedrooms Above
Refused
Householder permission for 2 storey side extension projecting to a gable front and rear with single storey rear living room extension. Ground floor lean-to extension to front elevation.
Refused
Demolition of existing garage and new two storey side extension, front porch and extended drive
Approved
Non-material amendment to planning permission FUL/2024/0467 to increase the height of the external bi-fold gate and side infill fence panel from 1800mm to 2400mm to match the height of the boundary fencing.
Approved
ARTICLE 10 CONSULTATION - PART SINGLE PART TWO STOREY SIDE EXTENSION
Approved
Single storey side extension and single storey rear extension
Approved
Convert garage to habitual room and side extension to existing dwelling at
2025/1113/AGP
Approved
A side extension to existing building to be used as a spray shed.
Approved
Certificate of Lawfulness of Proposed Development for the erection of a single storey rear extension, erection of a single storey side extension to create a garage, and addition of a dormer window to first floor side elevation
Approved
Lawful Development Certificate for proposed demolition of existing conservatory and erection of single story side extension
Approved
Single storey side extension (Retrospective) and proposed extraction flue.
Approved
Variation of condition 2 attached to permission P24/02531/F to amend the approved plans and to remove condition 4 (Land Contamination). Erection of a single storey side extension to facilitate change of use of holiday let to 1no. self build dwelling (Class C3) with associated works.
10/00408/FULL
Refused
Main Proposal is to Extend the Rear of Property (South) Providing Additional Floor Space and Rooms to both Ground Floor (Kitchen, Study and Family Room) and First Floors (2 x Bedrooms and 1 x Ensuite), Partial Side Extension to the West to Accommodate a Utility Room (Ground) and Ensuite (First) (Re-
17/1935/FUL
Refused
ALTERATIONS TO DERELICT DWELLINGHOUSE TO FORM HABITABLE DWELLINGHOUSE INCLUDING DEMOLITION OF EXISTING SIDE EXTENSION AND FORMATION OF ACCESS
Approved
Erection of a two-storey side extension and change of use of part of (former) quarry to residential land
11/00031/FUL
Approved
Proposed single storey side extension, comprising prefabricated modular accommodation cabin. Proposal to be formed on a temporary basis to meet the requirements of occupant. Access to accommodation from outside gained via ramped access to side door. Internal link formed through formation of door ope
10/02491/DC
Approved
Erection of single storey side extension to dwellinghouse ##PERMITTED DEVELOPMENT##
21/00125/FUL
Approved
Erection of a single storey rear/side extension following demolition of rear conservatory.
09/00879/NMA
Refused
Amendment to application reference no 08/01155/DET reduction in scale of side extension.
Refused
Side return has reduced in size, resulting in internal alterations. Two ground-floor windows increased in size. Rear windows have changed
Refused
Proposed single storey side extension and extension of curtilage, proposal includes new access position onto public road.
Refused
Use of former service station as car wash and cafe with hot food take away, erection of side extension, installation of extraction flue and associated car parking, boundary fencing and outdoor sitting area.
Approved
Change of use from C3 dwelling to C2 small childrens home and side extension together with associated internal and external works including an extended parking area with five additional onsite parking spaces with two EV charging points and two cycle spaces, the replacement of some external windows a
160289
Approved
Single storey side extension with decking
09/01363/WFULL
Refused
Two storey side extension to dwellinghouse
23/0185/VAROPDC
Refused
Proposed variation to Condition 2 of PP/2015/5829 (granted 4/3/2016) for retention of single storey front, rear and side extensions and mixed use as a restaurant (Land Use Class A3) and (shisha) lounge (Land Use Class Sui-Generis) (retrospective application) to amend the closure time of the shisha l
Refused
Retrospective erection of single storey side extension
Approved
Erection of single storey side extension
Related guides
Side extension planning permission guideBefore you spend £2,000+ on drawings — and risk getting refused
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