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.
From a first conversation about a double-storey extension to the day the site is cleared, homeowners in Ewell deal with us directly. We come out to measure up at no cost, explain the choices in plain terms and send a written quote. For context, comparable work in the South East usually falls within £67,000–£134,000 including VAT, and it is available across KT4, KT17, KT18 and KT19.
- Guide price
- £67,000–£134,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- KT4, KT17, KT18, KT19 and SM2
- Planning rules
- England
- Local area
- Surrey
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Ewell?
The costs listed here are typical for a double-storey extension around Ewell and include VAT. They reflect labour and material costs in the South East, about 12% above the national guide, giving a range of £67,000–£134,000. Exact pricing depends on your home, so we only fix it once a free site survey is done.
| Type of job | What it usually involves | Guide in Ewell |
|---|---|---|
| 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 does the job include in Ewell?
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- First-floor joists, stud walls and new openings upstairs
- Scaffolding for the full build, erected and inspected
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
What are homes like around Ewell?
Surrey has many Victorian and Edwardian villas, interwar semis in the commuter towns near London, and Arts and Crafts houses with tile-hanging and tall chimneys. Bargate stone appears around Godalming, and large detached homes are common in Guildford, Woking, Weybridge and the Surrey Hills villages.
Mild and relatively dry, with clay soils in the north and Weald that can move in summer; mature trees near houses affect foundations.
With that background in mind, here is how we typically handle a double-storey extension for homes in Ewell, from the first visit to the finished result.
Do you need permission in Ewell?
The notes below cover England, which is where Ewell sits. Rules change and every property is different, so we speak to the council before pricing your job.
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.
From survey to handover
Survey and measure
A free survey comes first. It gives us what we need to price a double-storey extension properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Quote in writing
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Booking the work
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Ewell property.
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.
What you can expect from us
Questions about a double-storey extension in Ewell
Can we live at home while it is built?
Most families stay at home during a double-storey extension. The new structure is built outside first, and we only break through into the existing rooms near the end, usually one floor at a time. Upstairs, this may mean a bedroom is out of use for a week or two. We fit dust screens, protect floors and stairs, and plan any time without water or power in advance.
Will the extension affect my neighbours?
A double-storey extension can affect neighbours' light, outlook and privacy, which is why planning departments look closely at height, depth and window positions. Side windows facing neighbours often need obscure glass. Work near a shared wall may also need party wall notices; the Party Wall etc. Act 1996 applies in England and Wales only. We talk through these points early so the design is realistic.
Do you cover Epsom, Sutton and Chessington?
Yes. As well as Ewell, we cover Epsom, Sutton and Chessington and the rest of Surrey. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
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.
Can you combine a double-storey extension with other work?
Yes. Because we manage several trades under one contract, we can plan a double-storey extension alongside other work on your Ewell home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
Also covering areas around Ewell
Coverage for Ewell spans KT4, KT17, KT18 and KT19. Close by, Epsom, Sutton and Chessington are covered too, and the rest of our UK-wide area follows the same survey-then-quote process from start to finish.