Annexe planning permission examples — what gets approved & refused
16,552 real decisions from 246 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
80.9%
approval rate across 16,552 decisions
That means roughly 1 in 5 annexe applications are refused — often due to avoidable design issues.
16,552
Decisions
13,394
Approved
3,158
Refused
246
Councils
Annexe applications cover self-contained living spaces within a property — from garage conversions to purpose-built garden annexes for elderly relatives. Councils often condition that the annexe remains ancillary to the main dwelling.
What these results show
• Annexes for elderly or disabled relatives are viewed more favourably than general-purpose annexes.
• Councils almost always condition that the annexe remains ancillary — it cannot be sold or let separately.
• Garden annexes with separate entrances and kitchens face more scrutiny as they can appear to be separate dwellings.
• Garage-to-annexe conversions generally have higher approval rates than new-build garden annexes.
⚠️ These are national examples. Your council could be stricter — or more lenient. See what actually gets approved on your street →
Real annexe decisions
Real examples showing what works — and what gets refused. Use the filters to compare approved and refused applications.
Refused
NON MATERIAL AMENDMENT TO APPLICATION 2022/0556/HHA (DOUBLE GARAGE EXTENSION WITH HOME OFFICE ANNEXE ABOVE AND SEPARATE OAK FRAMED CAR PORT - RESUBMISSION OF PLANNING APPLICATION 2021/0809/HHA) - TO REDUCE EXTENSION FOOTPRINT, REPLACEMENT OF LEAN TO STRUCTURE WITH OPEN STORAGE AREA WITH FLAT ROOF, R
Approved
To renew existing roof covering; replace degraded flat roof material on the annex. Remove existing felt cover and replace with like for like glass reinforced plastic (grp) laminate roofing at Holloway Lodge, B79 7NA
Approved
Full: Conversion of existing outbuilding to an annex, including insertion of windows, blocking up existing garage doors, raising the South-East elevation, installation of bi-fold doors with glass balustrade, and use of matching materials with vertical timber panels on the North-East elevation.
▸ Matching existing materials and design helps approval chances.
Approved
Consultation from Windsor and Maidenhead Borough Council in respect of the demolition of an existing building and erection of a three bedroom detached, two storey dwelling to provide ancillary accommodation.
▸ Two-storey approvals often involve setbacks from boundaries and matching materials.
Refused
Retrospective application for the construction of detached single storey residential annexe at rear of house; installation of 1.8m fence; alterations (Class C3)
Approved
Consultation from Waverley Borough Council for the erection of extensions and alterations including creation of a basement level and raising of roof ridge height to provide habitable accommodation in roof space with associated landscaping following demolition of existing single storey extension and
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Electronic record only, no paper fileDemolition of existing garages and erection of an annex with first floor accommodation, conservatory to rear and integral garage together with single storey rear extension to kitchen.(Amended plans received 16/01/07)
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Western Red Cedar (T1) Crown lift all round to approx 5m (property gutter level) Prune back the crown on the N/W side by up to 2m to clear the corner of the property. Remove 2 large stems on the east side of the tree to significantly reduce the overhang of the adjacent property.Plum, Lawson Cypress,
Approved
Demolish existing garage and erect single storey detached annexe to side of main dwellinghouse
▸ Single-storey extensions face less scrutiny than two-storey.
Refused
Non material amendment to planning permission 13/00742/FUL to include alterations to doors and windows, reorientation of roof to single storey annex to the side and use of natural stone to front and side annex elevations
052975
Approved
Change of use to the existing building from sui generis to a warehouse (Use Class B8) and erection of a 3-storey extension to the front to provide ancillary display showroom at ground floor with ancillary accommodation above, refurbishment of the warehouse, including recladding, installation of 2 ro
Approved
Application for Listed Building Consent - Repairs and alterations to existing mill to facilitate conversion to residential annexe (revised proposals to commenced approval 18/00096/FUL).
▸ Listed building applications succeed when design is sensitive to the original character.
240977/DPP
Approved
Conversion of existing garage outbuilding to form self-contained ancillary annex accommodation, including installation of new windows, rooflights and cladding
Approved
Non Material Amendment to planning permission 08/2186/FUL: Alteration of proposed ground floor side extension layout to form interconnected granny annex in place of pool room facilities. Proposed side extension windows to ground floor amended to single obscured glazed window to be open-able to allow
Approved
EXTENSION TO THE WEST OF THE SCHOOL BUILDING TO PROVIDE SCHOOL HALL, CLASSROOM, OFFICES, STAFF ROOM, TOILETS AND OTHER ANCILLARY ACCOMMODATION. PARTIAL REMOVAL OF EXISTING BOUNDARY WALL, PARTIAL RE-ROOFING OF EXISTING BUILDING, INTERNAL REMODELLING OF EXISTING BUILDING, CONSTRUCTION OF NEW STONE BOU
Approved
Conversion of existing garage and store including external alterations and roof lift to form ancillary accommodation
Refused
Certificate of Lawfulness for proposed development - removal of existing garage and erection of a single storey side extension for use an annexe to main dwelling
Approved
Demolition of outbuilding and erection of an annexe with disabled shower room.
▸ Accessibility needs strengthen the case for approval.
Approved
1. Scots Pine (T16 on tree survey map) - a branch overhanging a neighbouring property which is growing into their garage/annexe roof and has caused leaking damage. Tree surgeon recommended cutting branch back to existing growth point which will allow healthy growth and reduce future risk of damaging
Approved
Certificate of Lawfulness (Existing): Confirmation that annexe is associated with Thorpe Grange
Still scrolling?
You’re looking at national data. 19% of annexe applications get refused — but that number could be higher or lower in your area.
See what gets approved near your home →
Approved
Construction of a 5 storey block comprising of four 1-bedroom flats and ten 2-bedroom flats including part semi basement level comprising ancillary accommodation, external landscaping and cycle/refuse storage
Approved
Converting existing garage to granny annexe with front dormer
▸ Rear dormers are far more likely to be approved than front-facing ones.
Approved
Change of use of first floor including annex from offices to 1 No. two bedroom apartment retaining the ground floor in commercial use
Approved
Erection of a detached annex in the rear garden to form additional living accommodation
Approved
Replacement of annex building concrete tiled roof with a standing seam roof system
▸ Replacing an existing structure is generally viewed more favourably than building new.
Approved
The erection of a detached residential annex with associated works within the curtilage of Old Manor House (amended).
Approved
Trim height and spread of 1no. Portuguese Laurel to clear annex and allow access for works at St Paul's Nursery - tree in a conservation area
▸ Sympathetic design in conservation areas can still get approved.
2012/1256
Approved
Conversion of former retail unit (no.1A) into living annexe in association with adjoining house (no. 1) and alterations to frontage of no. 5A
Approved
Article 18 consultation from Salford Council (ref. 22/80765/HH) for existing pool house to be converted to granny annex
Approved
Removal of existing garage and erection of new garage and ancillary accommodation
Approved
Certificate of Lawfulness - Proposed for conversion of existing garage to habitable ancillary accommodation
22/00696/FUL
Approved
Outbuilding within domestic curtilage to form detached annex residential accommodation
Approved
One-and-a-half story extension to existing house with annexe, associated car parking and terraces
Approved
Construction of single storey detached annexe at rear; replacement boundary wall at front and construction of side boundary wall of house (Class C3) (amendments received 05/01/2026)
▸ Replacing an existing structure is generally viewed more favourably than building new.
23/01376/DIS
Approved
Application for approval of details reserved by condition 09 (Refuse & Recycling) of permission 21/00325/FUL for erection of single storey annexe to form ancillary pharmacy.
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
Works to 1no. Sorbus to remove major deadwood - less than 75mm, to remove 1no. branch towards annexe and to fit non invasive cobra brace. Works to fell 1no. Silver Birch, 4no. Ash, 1no. Willow, 1no. Ash and 3no. Larch all situated in the Marshfield Conservation Area.
▸ Sympathetic design in conservation areas can still get approved.
Refused
Certificate to confirm that the details submitted do not require planning permission (garage conversion to annexe including alterations)
Refused
The proposed conversion an existing garage into an annex with associated works
Refused
Conversion of Detached Garage to form Ancillary Accommodation
62/62/25/001
Refused
Lawful development certificate for the existing use of ancillary accommodation a
25/01998/FULL
Refused
Two storey extension to side of dwellinghouse for self-contained ancillary accommodation
▸ Two-storey extensions face higher scrutiny due to greater neighbour impact.
Refused
Application for a non-material amendment to planning permission reference number 20230553 to allow addition of a shower and kitchenette to provide an annexe for use ancillary to the main dwelling.
2021/02789/CLP
Refused
Use of the single storey outbuilding in the rear garden as a self-contained annexe flat ancillary to the single family dwellinghouse.
Refused
CHANGE OF USE OF RESIDENTIAL ANCILLARY ANNEX (C3) TO A SELF CONTAINED 1 BEDROOM APARTMENT WITH ALTERATIONS TO ELEVATIONS.
Refused
Partial demolition and rebuilding of existing swimming pool building to form garage and ancillary residential annex
Refused
Non Material Amendment to planning permission 11/0567/RSP: Replacement of existing front window with a door (to provide front access from granny annex which has existed since mid 1960's and always had its own separate entrance)
Refused
Development of granny annex at the rear of the host property for disabled family member.
Approved
Change of use and conversion of the disused outbuilding from office use to a self-contained residential annexe ancillary to the main dwellinghouse and associated alterations.
Approved
Installation of temporary modular building for use as ancillary accommodation with associated hard standing for the duration of the building works associated with Wyre Council planning application reference 24/1066/FUL
Approved
Erection of single storey rear extension for dependent relative accommodation
▸ Single-storey extensions face less scrutiny than two-storey.
Approved
NON MATERIAL VARIATION TO CHANGE OFFICE/GUEST GRANNY ANNEXE TO UTILITY ROOM AND DOMESTIC GARAGE OF PLANNING PERMISSION 24/1345/FUL
Approved
Alterations and Extension to Dwellinghouse to Form Ancillary Accommodation
Approved
Installation of a mobile home (to provide annexe accommodation)
24/00492/LAW
Approved
Siting of a caravan for ancillary accommodation use (proposed)
Refused
Erection of first floor extension to existing garage and conversion of garage to granny flat,
Refused
SECTION 191 APPLICATION - USE OF ANNEXE AS INDEPENDENT DWELLING
Refused
Alterations and extension to garage to form ancillary accommodation unit
Approved
Erection of self contained "Granny Annexe" within rear garden
24/289/CLEUD
Approved
Regularise the use of an annex as a house
Approved
Erection of Garage/Ancillary Accommodation
Before you spend £2,000+ on drawings — and risk getting refused
Your council may refuse the exact thing that got approved two boroughs away. See what actually gets approved near your property first.
See real decisions near your home →Don’t rely on national averages — see what happens on your street.
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