Teignmouth · Devon

Part single, part two-storey extensions in Teignmouth

Adding a part single, part two-storey extension in Teignmouth gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in England.

Teignmouth: the key facts for this kind of project.

Postcode districts
TQ14
County / area
Devon, England
Price region
South West England
Guide price
£74,000–£102,000 (£2,060–£2,830 per m²)
Approval route
It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns
Dawlish (2.8 miles), Kingsteignton (3.8 miles), Newton Abbot (5.2 miles)
Distance to Plymouth
about 30.9 miles
First visit
Free, no obligation

About a part single, part two-storey extension

A part single, part two-storey extension suits you if you want a generous ground floor but only need one extra room upstairs, or if a full two-storey design would affect a neighbour too much. You get design options that test where the two-storey part works best, the approvals your nation needs, structural design, building regulations approval and the build, carried out by vetted teams working under S&K.

Teignmouth sits about 30.9 miles from Plymouth. Closer to home, Dawlish is 2.8 miles away and Kingsteignton 3.8 miles.

What it costs in Teignmouth

Our guide for South West England is £2,060–£2,830 per m² including VAT. On a project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total), that puts a part single, part two-storey extension in Teignmouth at roughly £74,000–£102,000. Design fees, structural calculations and approval fees are separate and listed on our prices page.

SpecPer m²A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total)
Essential£1,900–£2,610 per m²£68,000–£94,000
Standard£2,060–£2,830 per m²£74,000–£102,000
Premium£2,470–£3,400 per m²£89,000–£122,500

Planning and building regulations in Teignmouth

In England, the extension can only be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 7 m from the rear boundary, with matching materials and roof pitch. We check the whole design against the rules, including the 50% garden coverage limit. If any part fails, or extends beyond a side wall on two floors, you need planning permission, costing £548 (or £575 for applications made from 8 December 2026).

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 Teignmouth homes

Light into the kitchen

The single-storey part is the place for roof lights or a lantern, which bring daylight deep into the plan. In England, glazing is normally limited to 25% of the new floor area plus any windows removed, unless calculations show the house still performs, so we plan the balance early.

The roof junction

Where the single-storey roof meets the two-storey wall you need a sound weathering detail, usually a lead or similar flashing, and enough height for roof lights or a lantern. We set the roof falls and the upstairs window sill heights together so they do not clash.

How we'd run your project

  1. Visit and first ideas

    One of our team visits your house in Teignmouth, checks the walls, roof and drains, and sketches out options with you.

  2. Plans, then approval

    Measured survey, design, then the right approval route for your house. We explain each step before we take it.

  3. Structure and building control

    A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.

  4. Build and hand over

    We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about part single, part two-storey extensions in Teignmouth

Who handles building regulations for a project in Teignmouth?

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 long does a part single, part two-storey extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

How much does a part single, part two-storey extension cost in Teignmouth?

Our guide for South West England, which covers Teignmouth, is £2,060–£2,830 per m² including VAT. A typical project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) comes to about £74,000–£102,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Which side should the two-storey part go on?

Usually the side furthest from the nearest neighbour's windows, so the single-storey part sits nearest them and keeps their light. Other factors are where the stairs land upstairs, which room needs the extra space and where drains run. We sketch options at the design stage and explain which is most likely to be approved.

Can the single-storey part be deeper than the two-storey part?

With planning permission, yes, and that is often the point of the design: the ground floor projects further into the garden while the first floor stays back from neighbours. Under permitted development, the depth limits for extensions of more than one storey can apply to the whole extension, so we confirm which route applies before drawings are finalised.

Nearby

The same service in neighbouring towns:

Other extensions in Teignmouth

All two-storey extension services in Teignmouth · Part single, part two-storey extensions across Devon

The quickest next step is a visit. We'll look at your house in Teignmouth and give you an honest view of the options.

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