A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
If you have a double-storey extension on your list for a property in Ashford, Kent, we can help from the first measurements to the final clean-up. For a typical home, plan for 14–22 weeks on site, though larger or more complex jobs take longer. We cover postcodes TN23 and TN24 and nearby Faversham, Canterbury and Folkestone, and every quote we send is fixed for the scope described in it.
- Guide price
- £67,000–£134,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- TN23 and TN24
- Planning rules
- England
- Local area
- Kent
- Survey
- Free, with a written quote
Double-storey extensions prices in Ashford, Kent
No two jobs cost exactly the same, but the ranges below give a fair picture of a double-storey extension in Ashford, Kent. Pricing for the South East runs about 12% above the national guide, and the overall guide is £67,000–£134,000 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in Ashford |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £45,000–£73,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £67,000–£134,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £112,000–£202,000 |
Expect these to shape the final quote:
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
What do you get?
- Insulated cavity walls with brick or render to match the house
- First-floor joists, stud walls and new openings upstairs
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Building in Ashford, Kent
Kent's older buildings include oast houses, weatherboarded cottages, Wealden timber-framed houses and Kentish ragstone walls. Medway towns have long rows of Victorian terraces, Margate and Ramsgate have Regency and Victorian seafronts, and Ashford, Maidstone and Dartford have seen large new estates alongside interwar and post-war housing.
Victorian terraces suit loft rooms and rear extensions; weatherboarded and timber-framed buildings may need cladding repairs and lime work. Newer estate homes often take garage conversions, porches and landscaping.
These patterns matter for a double-storey extension: older walls, roofs and floors in Ashford, Kent can need different materials or extra preparation compared with newer homes.
Do you need permission in Ashford, Kent?
Planning law differs across the UK. For a home in Ashford, Kent, it is the England rules below that count, and we check them with the council ahead of any quote.
In England, a two-storey rear extension can only be permitted development if it is no more than 3 m deep, at least 7 m from the rear boundary and finished to match the house. Most double-storey and all two-storey side extensions need full planning permission.
Building Regulations approval is needed, with structural calculations for beams, foundations and the roof. The Party Wall etc. Act 1996 often applies on semi-detached and terraced houses.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
What happens after you get in touch?
Survey and measure
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a double-storey extension.
Quote in writing
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Booking the work
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a double-storey extension are in place before the first day on site.
Build and hand over
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
How we work
Double-storey extensions in Ashford, Kent: questions
How is the new roof joined to the existing house?
The new roof is usually tied into the existing roof so the two read as one. On a rear extension this often means a lower ridge or a hipped end, with valleys where the slopes meet. We strip back some existing tiles, fix new rafters and battens, and lay matching tiles or slates. Lead or proprietary flashings seal the junctions so water runs off properly.
Do I need planning permission in Ashford, Kent?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Ashford, Kent is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
How long does a double-storey extension take?
A double-storey extension typically takes 14–22 weeks on site, depending on size, roof design and weather. Foundations and ground-floor walls come first, then the first-floor joists, upper walls and roof. Once it is weathertight, electrics, plumbing, plastering and finishes follow. Allow extra time beforehand for drawings, calculations and approvals. We give you a stage-by-stage programme with your quote.
Do I need planning permission for a two-storey extension?
Most two-storey extensions need planning permission, but it depends on the size, height and position, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, a two-storey rear extension can sometimes be built under permitted development if it is no deeper than 3m and at least 7m from the rear boundary. We check what applies before quoting.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
Nearby towns
Whether you're in the centre of Ashford, Kent or on its outskirts, TN23 and TN24 addresses are covered. We extend the same service, and the same fixed-price approach, to Faversham, Canterbury and Folkestone.

