Double-storey extensions for homes in Ewell
We design and build double-storey extensions for houses in Ewell, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in EwellFrom £42,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsKT17, KT18, KT19
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.
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 Ewell
Site visits are available across Ewell (KT17, KT18, KT19). We also work in nearby Epsom (2 miles), Banstead (3 miles), Leatherhead (5 miles), Esher (5 miles).
Just over the Greater London border, Worcester Park is about 2 miles away. In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
How much does a double-storey extension cost in Ewell?
For Ewell we adjust our national guide rates by ×1.12, the factor we use for South East England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Ewell: £1,740 to £3,360 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £42,500 – £51,000 | £48,000 – £63,500 | £61,500 – £81,000 |
| 4 m × 4 m, two floors 32 m² | £55,500 – £66,500 | £64,500 – £84,500 | £82,000 – £108,000 |
| 4 m × 6 m, two floors 48 m² | £83,000 – £99,500 | £96,500 – £126,500 | £123,500 – £161,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Is a double-storey extension right for your house?
- Homeowners who would otherwise consider moving
- Houses with enough distance to the rear or side boundary
- Growing families who need a bedroom as well as a bigger kitchen
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
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.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Ewell
Who do I contract with for a double-storey extension in Ewell?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Do I need building regulations approval in Ewell?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Ewell be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do I need a Party Wall Agreement?
If you are in England or Wales and the work involves a shared wall or digging foundations close to a neighbour, the Party Wall etc. Act 1996 applies and notices must be served before work starts. We tell you which notices are needed.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,740 to £3,360 per m² of new floor area including VAT, compared with £1,960 to £3,810 per m² for single-storey work, because the foundations and roof are shared across two floors.
Book a free site visit in Ewell
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
Tell us a little about the project and we will arrange a time.