Two-storey side extensions in Exeter
Thinking about a two-storey side extension in Exeter? We design it, take it through the approvals it needs and build it, with one team responsible from the first visit to the final certificate.
Before you start in Exeter, here's what applies.
- Postcode districts
- EX2, EX4, EX6 and EX17
- County / area
- Devon, England
- Price region
- South West England
- Guide price
- £88,500–£119,000 (£2,110–£2,830 per m²)
- Approval route
- Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
- Nearest towns
- Heavitree (1.4 miles), Exmouth (9.2 miles), Dawlish (10.2 miles)
- Distance to Plymouth
- about 36.4 miles
- First visit
- Free, no obligation
About a two-storey side extension
A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.
We cover Exeter (EX2, EX4, EX6 and EX17) and the places around it, including Heavitree (1.4 miles), Exmouth (9.2 miles) and Dawlish.
What it costs in Exeter
Expect a two-storey side extension in Exeter to land somewhere around £88,500–£119,000 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Our South West England guide rate is £2,110–£2,830 per m², including VAT. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.
| Spec | Per m² | A 3 m × 7 m footprint on two floors (42 m² of new floor space) |
|---|---|---|
| Essential | £1,940–£2,610 per m² | £81,500–£109,500 |
| Standard | £2,110–£2,830 per m² | £88,500–£119,000 |
| Premium | £2,530–£3,400 per m² | £106,500–£143,000 |
Planning and building regulations in Exeter
In England, a two-storey side extension always needs householder planning permission, because permitted development only allows single-storey extensions beyond a side wall. The fee is £548 (or £575 for applications made from 8 December 2026), and councils should decide within 8 weeks of validation. Expect them to look at set-back, roof height, gaps to the boundary and the effect on neighbours.
Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.
Design points for Exeter homes
Side windows, boundaries and gutters
Upstairs windows in the side wall face the neighbour, so they are usually obscure-glazed and fixed, or left out. Building close to the boundary also raises questions about foundations, overhanging gutters and access for maintenance, so we design the eaves and gutter to stay within your land.
Matching the ridge and roof
A hipped house usually needs a hipped extension roof, and a gabled house a gable. Matching the pitch, tiles, ridge detail and brick bond is what makes a side extension look original rather than added, and councils look closely at it on a front-facing addition.
How we'd run your project
Visit and first ideas
One of our team visits your house in Exeter, checks the walls, roof and drains, and sketches out options with you.
Get it approved
Once you're happy with the design we submit it to the council for Exeter and deal with any questions from the planning officer.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about two-storey side extensions in Exeter
Which postcodes do you cover around Exeter?
We cover Exeter (EX2, EX4, EX6 and EX17) and nearby places including Heavitree, Exmouth and Dawlish, plus the rest of Devon. The first site visit is free.
Do I need planning permission for a two-storey side extension in Exeter?
Exeter is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
Who handles building regulations for a project in Exeter?
We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
How much does a two-storey side extension cost in Exeter?
Our guide for South West England, which covers Exeter, is £2,110–£2,830 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £88,500–£119,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Can I build a two-storey side extension over my driveway?
Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.
Nearby
Close to Exeter? We work across the area, including:
Other extensions in Exeter
- Rear
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Exeter · Two-storey side extensions across Devon
Book a free site visit in Exeter and we'll tell you what's possible, what approvals you need and what the design stage would cost.