Side Extension planning permission examples — what gets approved & refused
174,599 real decisions from 249 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: March 2026
83.8%
approval rate across 174,599 decisions
That means roughly 1 in 6 side extension applications are refused — often due to avoidable design issues.
174,599
Decisions
146,286
Approved
28,313
Refused
249
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
• Side return extensions on terraced houses have very high approval rates — they’re a well-established pattern.
• Two-storey side extensions face more scrutiny, especially where they would close the visual gap between semi-detached pairs.
• Councils often insist on a “set back” from the front elevation to prevent a terracing effect.
• Matching materials matter — design refusals frequently cite poor visual integration with the existing house.
⚠️ 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.
16/00049/FUL
Approved
Demolish existing flat roofed single storey side extension and replace with single storey kitchen diner and new front entrance porch.
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Single storey wrap-around extension with pitched roof. Side extension to have parapet wall on boundary. Remaining side and rear boundary to have new fence measuring 1.8m in height from pavement level.
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Two storey side extension and the addition of a pitched roof to the existing rear flat roof extension.
▸ A roof that matches the existing house signals good design to planning officers.
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
▸ A roof that matches the existing house signals good design to planning officers.
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
22/02173/PDVLR
Approved
Prior Notification for larger home extension (Part 1 Class A): Single storey side/rear extension to the depth of 6m with a maximum roof height of 3m and eaves height of 2.4m with 2 double French doors
▸ Modest single-storey extensions within typical depth limits have strong approval rates.
Approved
Non-material Amendment: To replace the material type used to construct the corners of the first floor side extension with timber and then clad with vertical slates as opposed to the original metal alloy bay poles clad in UPVC and remove the glass roof lantern for application 22/01143/FUL
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
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
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
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Erection of a single storey side extension including connection to existing detached garage, part single/part two storey rear extension together with amendments to roof of existing garage
▸ Single-storey extensions face less scrutiny than two-storey.
Refused
Non material amendment following the grant of R/73/25/HH to change colour of window to Anthracite Gray, change porch design including flat roof to front and side extensions, removal of new window to East and West elevations and reconfiguration of kitchen doors/window.
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
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
24/01955/LBC
Refused
Listed building consent for external alteration to dwellinghouse including installation of windows, doors, re-location of heat pump, removal of existing side extension, removal of rendering, and formation of hardstanding. Alteration to previous application (22/00528/LBC)
Approved
Erect single storey side extension, increase height of roof to form habitable accommodation and erect dormer windows to side (amended proposal)
▸ Single-storey extensions face less scrutiny than two-storey.
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.
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Increase in vacant pub roof height and construction of a first floor side extension together with insertion of dormer windows to both sides of rooftop to facilitate the conversion of the building into 7 x 1 bed flats, demolition of existing garages, a single storey extension to existing vacant comme
▸ Single-storey extensions face less scrutiny than two-storey.
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
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Non material amendment relative to Planning Permission 21/01267/PP Erection of single storey rear and side extension - The rear section of the extension comprising a kitchen/diner is removed from the proposal, with the garage remaining
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Non-material amendment to planning permission (ref. 23/01224/FUL) to allow the installation of rooflights on the northern and southern roof slope at second floor level and on the single storey side element on the northern side as well as installation of a ground floor northern flank window.
▸ Single-storey extensions face less scrutiny than two-storey.
21/03428/NMV2
Approved
Alterations, extensions and formation of dormer windows to dwellinghouse (Non Material Variation to retain existing garage and rooflights (proposed rebuilding of garage, side extension, new rooflights and installation of photovoltaic panels removed from works to 21/03428/FULL)
▸ Rear dormers are far more likely to be approved than front-facing ones.
Still scrolling?
You’re looking at national data. 16% of side extension applications get refused — but that number could be higher or lower in your area.
See what gets approved near your home →
Approved
Erection of a single storey side and rear extension with attached single storey garage following demolition of the existing detached garage.
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Erection of a single storey side extension to a Grade II listed building
▸ Listed building applications succeed when design is sensitive to the original character.
Refused
Demolition of Existing Single Garage and Erection of Two Storey Side Extension
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
Refused
Two Storey Side Extension To Provide Garage, WC & Dining Room On Ground Floor With 2No. Bedrooms Above
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
Refused
Demolition of existing conservatory; construction of two storey side/rear extension
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
Refused
Erection of a single storey side and rear wrap around extension. Roof extensions and alterations including raising of the ridge, 2 no. front facing dormers and 1 no. rear facing dormer to facilitate loft conversion. Changes to fenestration. Following removal of existing garage.
Approved
Application for Prior Approval Under Part 6 Schedule 2 of the Town and Country Planning (General Permitted Development) Order 2015 (as amended) for a Proposed Side Extension to Existing Tractor Store
▸ Prior approval applications that meet the criteria are rarely refused.
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.
▸ Matching existing materials and design helps approval chances.
Approved
ARTICLE 10 CONSULTATION - PART SINGLE PART TWO STOREY SIDE EXTENSION
▸ Two-storey approvals often involve setbacks from boundaries and matching materials.
Approved
Erection of two storey side extension, alterations to existing garage
▸ Two-storey approvals often involve setbacks from boundaries and matching materials.
Approved
Application for a Lawful Development for a Proposed single storey side extension.
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Erection of a single storey side extension to form additional living accommodation
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Convert garage to habitual room and side extension to existing dwelling at
Approved
Lawful Development Certificate for proposed demolition of existing conservatory and erection of single story side extension
Approved
Single storey rear extension and 1.5 storey side extension to house
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Single storey side extension (Retrospective) and proposed extraction flue.
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Single storey side and rear extensions to dwellinghouse (Non Material Variation to amend external finish as stated on approved plans to 19/01003/FULL)
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Certificate of Lawfulness for a Proposed Single Storey Side Extension
▸ Single-storey extensions face less scrutiny than two-storey.
P2022/0988/FUL
Approved
Alterations including erection of three storey side extension, first floor rear
Approved
CERTIFICATE OF LAWFUL DEVELOPMENT (S192) FOR THE PROPOSED ERECTION OF A SINGLE STOREY SIDE EXTENSION TOGETHER WITH THE INSTALLATION OF A CARPORT
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Demolition of attached garage and erection of single-storey side extension to dwellinghouse
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
Refused
Householder Planning Application - Single storey side extension.
1790/24
Refused
Double storey side extension. Remove external gutter, raise flank wall and creat
Approved
Erection of a two-storey side extension and change of use of part of (former) quarry to residential land
▸ Two-storey approvals often involve setbacks from boundaries and matching materials.
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
▸ Single-storey extensions face less scrutiny than two-storey.
10/02491/DC
Approved
Erection of single storey side extension to dwellinghouse ##PERMITTED DEVELOPMENT##
▸ Single-storey extensions face less scrutiny than two-storey.
21/00125/FUL
Approved
Erection of a single storey rear/side extension following demolition of rear conservatory.
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Erection of single storey side and rear extension along with raised decking to front
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Non material amendment to P19/13488/F to add double doors to garage/workshop and single door to side extension
09/00879/NMA
Refused
Amendment to application reference no 08/01155/DET reduction in scale of side extension.
▸ Excessive scale and bulk relative to the original dwelling trigger refusals.
Refused
Certificate of Lawfulness for proposed side extension to house
Approved
Single storey rear extension and 2 storey side extension
▸ Single-storey extensions face less scrutiny than two-storey.
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
▸ Replacing an existing structure is generally viewed more favourably than building new.
160289
Approved
Single storey side extension with decking
▸ Single-storey extensions face less scrutiny than two-storey.
09/01363/WFULL
Refused
Two storey side extension to dwellinghouse
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
Refused
Two storey Side Extension and rear single storey extension
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
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
NP/25/0432/FUL
Refused
Two storey side extension and replacement rear extension
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
Related guides
Side extension planning permission guideBefore you spend £2,000+ on drawings — and risk getting refused
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