England
Rear extensions in Buckinghamshire
Across Buckinghamshire we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Milton Keynes, High Wycombe and Aylesbury.
What are homes in Buckinghamshire like to extend?
Commuter semis and detached houses make up much of Buckinghamshire, and longer gardens make England's prior approval route for deeper rear extensions worth considering.
Rear extension prices in Buckinghamshire
South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations. Per square metre including VAT, standard specification:
| Extension | Per m² |
|---|---|
| Single-storey rear extension | £2,130–£3,470 |
| Two-storey (per m² across both floors) | £2,020–£3,020 |
| Side return | £2,580–£4,260 |
| Wraparound | £2,460–£4,030 |
| Glass-led | £3,140–£5,380 |
Planning and building rules in Buckinghamshire
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Every rear extension in England needs Building Regulations approval, whether or not planning is needed. You can use the council's building control service or a registered building control approver, by full plans (checked before work, usually within five weeks) or a building notice, and you get a completion certificate at the end.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Rear extensions we build in Buckinghamshire
- Rear extensions for detached houses
- Rear extensions for bungalows
- Flat-roof rear extensions
- Pitched and lean-to roof rear extensions
- Knocking through to a rear extension
- Roof lanterns and rooflights for rear extensions
- Permitted development rear extensions
- Larger home extension prior approval (England)
- Rear extension plans and planning applications
- Building Regulations for rear extensions
- Single-storey rear extensions
- Two-storey rear extensions
- Kitchen-diner rear extensions
- Side return extensions
- Wraparound extensions
- Glazed and glass-box rear extensions
- Rear extensions for terraced houses
- Rear extensions for semi-detached houses
Towns and districts in Buckinghamshire
The main places we cover in Buckinghamshire include Milton Keynes, High Wycombe and Aylesbury, across postcode areas HP, MK and SL.
| Town | Postcode districts | Nearest town we also cover |
|---|---|---|
| Milton Keynes | MK3, MK4, MK5 | Newport Pagnell (3.5 miles) |
| High Wycombe | HP11, HP12, HP13 | Marlow (4.3 miles) |
| Aylesbury | HP19, HP20, HP21 | Tring (6.8 miles) |
| Bletchley | MK1, MK2, MK3 | Milton Keynes (3.5 miles) |
| Amersham | HP6, HP7 | Amersham on the Hill (0.7 miles) |
| Chesham | HP5 | Amersham on the Hill (1.8 miles) |
| Gerrards Cross | HP9, SL9, UB9 | Chalfont St Peter (1.6 miles) |
| Chalfont St Peter | SL9 | Gerrards Cross (1.6 miles) |
| Marlow | SL7 | Maidenhead (4.0 miles) |
| Amersham on the Hill | HP5, HP6, HP7 | Amersham (0.7 miles) |
- Milton Keynes
- High Wycombe
- Aylesbury
- Bletchley
- Amersham
- Chesham
- Gerrards Cross
- Chalfont St Peter
- Marlow
- Amersham on the Hill
- Newport Pagnell
- Beaconsfield
- Buckingham
Areas near Buckinghamshire
FAQ
Questions people ask
How much does a rear extension cost in Buckinghamshire?
As a guide, £2,130–£3,470 per square metre including VAT for a standard single-storey extension at South East England rates.
Do I need planning permission in Buckinghamshire?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Which towns in Buckinghamshire do you cover?
13 towns and districts, including Milton Keynes, High Wycombe and Aylesbury.
Do you handle building control?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.