Side Extension planning permission examples — what gets approved & refused
172,730 real decisions from 304 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: June 2026
85.3%
approval rate across 172,730 decisions
That means roughly 1 in 7 side extension applications are refused — often due to avoidable design issues.
172,730
Decisions
147,253
Approved
25,477
Refused
304
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.
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
▸ 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.
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
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)
▸ Replacing an existing structure is generally viewed more favourably than building new.
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.
Approved
Certificate of Lawful Use for Single Storey Pitched Roof Side Extension
▸ Single-storey extensions face less scrutiny than two-storey.
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
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
Householder Prior Approval - Single storey side extension which extends beyond the rear wall of the original house by 8 metres with a maximum height of 4 metres and a height of 2.45 metres to the eaves
▸ Prior approval applications that meet the criteria are rarely refused.
Approved
Double storey side extension, single storey rear extension and rear roof dormer extension.
▸ 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
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.
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.
Approved
Proposed first floor side extension above existing garage and a single storey rear kitchen extension
▸ Single-storey extensions face less scrutiny than two-storey.
Still scrolling?
You’re looking at national data. 15% 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.
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
Demolition of existing garage and new two storey side extension, front porch and extended drive
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
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
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
Single storey side extension and single storey rear extension
▸ Single-storey extensions face less scrutiny than two-storey.
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
▸ Single-storey extensions face less scrutiny than two-storey.
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.
P2022/0988/FUL
Approved
Alterations including erection of three storey side extension, first floor rear
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
Certificate of Lawful Proposed Development for erection of single storey side extension
Refused
Proposed two storey side extension with attached garage on the ground floor. Garage conversion to habitable space with associated modifications and boundary wall at the north and west with a gate on the west boundary
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
Refused
Householder Planning Application - Single storey side extension.
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.
Approved
Erection of Single storey side extension and alterations to fenestration
▸ Single-storey extensions face less scrutiny than two-storey.
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
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.
Refused
Certificate of Lawfulness for proposed side extension to house
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
Householder: Single storey side extension and new porch.
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
Side extension to agricultural straw barn
Related guides
Side extension planning permission guideBefore you spend £2,000+ on drawings — and risk getting refused
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