Single Storey Extensions in Ampthill | Building Control Handled

A single storey extension in Ampthill typically costs £2,400–£3,200 per m² finished ready for decoration — roughly £29,000–£38,500 for a 12m² rear extension, with any kitchen fit-out priced separately. An extension in Ampthill needs building regulations approval — Central Bedfordshire Council publishes its building control charges as a schedule (plan charge on submission, inspection charge after the first visit); ask its Building Control team for the current figure for your size of extension. It either fits within permitted development or needs householder planning permission, which costs £548 from April 2026 and is decided within eight weeks.

Typical cost: £2,400–£3,200 per m²
Council: Central Bedfordshire Council
Planning: Permitted development or £548 application
Building regulations: Needed
Ground: Greensand sand, clay to the north

Prices are our 2026 guide prices; your fixed price comes in writing after the free visit. Council fees checked October 2026.

Extensions in Ampthill

Extensions on Ampthill houses

Ampthill is a Georgian market town — its market place, pump and clock tower were improved in the 1780s — with the thatched Ossory Cottages, Ampthill Great Park beside it, and newer estates such as Ampthill Heights and Ampthill Gardens on the former brewery land.

Most extensions we build here are single storey at the rear, matched to the existing brick or stone, with the drainage and any sewer nearby checked before the footings are dug.

We cover Ampthill (MK45) and the areas around it, including Maulden, Flitwick, Millbrook, Houghton Conquest, Clophill, Steppingley and Flitton. Travel does not change the price.

Ampthill specifically

Ground, drainage and conservation in Ampthill

The town stands on the sandy Greensand Ridge, yet gives its name to the Ampthill Clay on the lower ground to the north, so ground can change from free-draining sand to heavy clay within a short distance. Because the ground varies, the foundation depth is confirmed from the trial holes and agreed with building control on site.

Ampthill Conservation Area is large and includes Church Square. Many historic frontages sit right on the pavement, so boundary walls and railings matter to the planners. There is no Article 4 direction.

Sources: Central Bedfordshire conservation areas and appraisals.

Central Bedfordshire Council

Planning, building regulations and fees in Ampthill

Step 1Check whether it fits permitted development, and if you want certainty apply for a lawful development certificate (£274). Planning Portal: extensions
Step 2In the Ampthill conservation area, side extensions and rear extensions of more than one storey always need planning permission.
Step 3If permission is needed, apply for householder planning permission (£548 from April 2026), decided within eight weeks. Pre-application advice from Central Bedfordshire Council costs £150 for written advice, or £300 with a meeting (both including VAT), with a reply within four weeks. Planning Portal: application fees
Step 4Apply for building regulations approval: Central Bedfordshire Council publishes its building control charges as a schedule (plan charge on submission, inspection charge after the first visit); ask its Building Control team for the current figure for your size of extension. Central Bedfordshire Council: building control charges
Step 5We build to the approved drawings and work to the building control inspections at each stage.

Council fees and rules checked October 2026. Planning fees are the national fees from 1 April 2026.

What is included

Everything below is included in an extension

Drawings and the building control application
Foundations set from a trial hole, not a guess
Drainage diverted or rebuilt where it needs to be
Build-over and party wall matters flagged and handled
Roof and threshold junctions detailed properly
Electrics and plumbing by registered trades, with certificates
Building control sign-off at the end
A five year guarantee, in writing

Questions

Extensions in Ampthill: questions

How much does a single storey extension cost in Ampthill?

A single storey extension in Ampthill typically costs £2,400–£3,200 per m² finished ready for decoration — roughly £29,000–£38,500 for a 12m² rear extension, with any kitchen fit-out priced separately. Your fixed price comes in writing after the free visit.

How much does planning and building control cost for an extension in Ampthill?

Householder planning permission is £548 (from April 2026) if you need it, or £274 for a lawful development certificate. Central Bedfordshire Council publishes its building control charges as a schedule (plan charge on submission, inspection charge after the first visit); ask its Building Control team for the current figure for your size of extension.

Do I need planning permission for an extension in Ampthill?

Many single-storey rear extensions are permitted development within size limits. In the Ampthill conservation area, side extensions and rear extensions of more than one storey always need permission.

Is Ampthill in a conservation area?