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.
Anyone planning a double-storey extension in Tiverton wants three things: a clear price, a realistic timetable and a tidy job. We publish a guide of £61,000–£122,000 including VAT for the South West up front, explain that work normally takes 14–22 weeks on site, and confirm both in writing after a free survey of your property.
- Guide price
- £61,000–£122,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- EX16
- Planning rules
- England
- Local area
- Devon
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Tiverton?
The table below shows guide prices for a double-storey extension in Tiverton. They are based on rates in the South West, which run about 2% above the national guide, giving an overall range of £61,000–£122,000. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in Tiverton |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £41,000–£66,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £61,000–£122,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £102,000–£184,000 |
Expect these to shape the final quote:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
What do you get?
- Groundworks, foundations and below-ground drainage
- First-floor joists, stud walls and new openings upstairs
- Scaffolding for the full build, erected and inspected
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Homes in Devon
Devon is known for cob and thatch cottages, especially in mid and east Devon, alongside granite on Dartmoor and red sandstone around Exeter. Exeter and Plymouth have Georgian and Victorian terraces, Plymouth's centre was largely rebuilt after the war, and seaside towns such as Torquay and Exmouth have rendered villas and newer estates.
Cob and stone homes need breathable lime plaster and render rather than cement. Victorian terraces suit loft rooms and window replacement, while post-war and newer homes often take extensions, rendering and roofline renewal.
If your house in Tiverton fits one of these patterns, it helps us anticipate what a double-storey extension will involve, though we always confirm the details on site.
Permissions for a double-storey extension in Tiverton
Which rules apply depends on where you live. For Tiverton, the answer is England, and the points below reflect that; we verify them with the council before quoting.
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.
The four stages
Survey and measure
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a double-storey extension so the price reflects your home.
Price and scope agreed
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
Frequently asked questions
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 Tiverton 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.
Is a double-storey extension better value than single-storey?
A double-storey extension usually gives better value per square metre than a single-storey one, because the same foundations and roof serve twice the floor area. The overall cost is higher, and planning can be harder because of the effect on neighbours. If you might want an extra bedroom later, building both floors now avoids a second round of disruption and scaffolding.
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.
How much will a double-storey extension cost in Tiverton?
As a guide, expect to pay £61,000–£122,000 including VAT for a double-storey extension in Tiverton. That range is adjusted for the South West, which runs about 2% above the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
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.
Near Tiverton
Coverage for Tiverton spans EX16. Close by, Exeter, Heavitree and Taunton are covered too, and the rest of our UK-wide area follows the same survey-then-quote process from start to finish.