house-extension.uk

Bedroom extensions across Kent

Our design and build teams take on bedroom extensions in Kent, from the first measured survey through planning and building control to the finished room.

  • Guide priceFrom £29,000 inc VAT
  • PlanningUsually a householder application
  • Towns covered23
  • Site visitFree, no obligation
Bedroom in an extension with a roof window and an en-suite shower room

Guide prices for Kent

These guide figures apply our South East England adjustment (×1.12) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.

Typical rates in Kent: £1,790 to £3,580 per m² including VAT, depending on specification.

SizeEssentialStandardPremium
One bedroom
12 m²
£29,000 – £35,500£29,000 – £38,000£32,000 – £43,500
Bedroom and en-suite
18 m²
£32,000 – £39,500£38,000 – £49,500£48,000 – £65,000
Two rooms
30 m²
£53,500 – £66,000£63,500 – £82,500£80,500 – £108,000

Try the guide-price tool to see a range for your own size and finish.

What is included

  • En-suite drainage and ventilation design
  • Layout options: two-storey, over-garage or ground floor
  • Structure, roof, insulation and finish
  • Planning drawings and application
  • Fire safety: escape windows and smoke alarms to building regulations
  • Heating extended to the new rooms

New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.

Will the council need to approve it?

In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.

Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.

Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.

If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.

Applications are decided by the local planning authority (your district, borough or unitary council).

Extensions in and around Kent

Towns we cover in Kent include Maidstone, Gillingham, Chatham, Tunbridge Wells, Folkestone, Margate, Ashford, Kent, Canterbury. The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.

How the project works

Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.

  1. Free site visit

    It starts with a visit to your house to measure, check access and talk through ideas and budget.

  2. Design and approvals

    Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.

  3. Fixed written price

    You receive a written, itemised price and programme. Nothing starts until you are happy with it.

  4. Build and sign-off

    Work is carried out to the agreed programme, inspected by building control and signed off at the end.

Questions people ask about bedroom extensions

Do you cover all of Kent?

Yes, across the whole of Kent. Site visits are free and there is no obligation.

Can I see a price before committing to anything?

Yes. The guide prices on this page are adjusted for Kent, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.

Do I need building regulations approval in Kent?

Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.

Will a new bedroom need planning permission?

Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.

How much does a bedroom extension cost?

Our guide range is about £1,790 to £3,580 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £38,000 to £49,500 at standard spec, depending on whether it is part of a larger two-storey build.

Book a free site visit in Kent

We will measure up, check the planning position and give you honest guide figures.

  • Free, no-obligation site visit
  • Planning route checked before you spend on drawings
  • Written price once the design is agreed
  • Building control sign-off at the end

Prefer to talk? Call 0800 088 6341 or .

Book a free site visit

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