Part single, part two-storey extensions in Lochgilphead
A part single, part two-storey extension is one of the most space-efficient ways to add bedrooms and living space to a house in Lochgilphead, because the new floors share one set of foundations and one roof.
Lochgilphead is outside our usual mainland visit area, so visits and projects here are by arrangement. We'll agree any travel costs with you before anything is booked.
Before you start in Lochgilphead, here's what applies.
- Postcode districts
- PA30 and PA31
- County / area
- Argyll and Bute, Scotland
- Price region
- Scotland
- Guide price
- £67,500–£93,000 (£1,880–£2,580 per m²)
- Approval route
- Planning permission is usually needed: Class 1B permitted development only applies if every part of the extension is at least 10 m from all boundaries. A building warrant is needed before work starts.
- Nearest towns
- Rothesay (20.1 miles), Dunoon (20.4 miles), Gourock (24.3 miles)
- Distance to Helensburgh
- about 27.3 miles
- First visit
- By arrangement
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, a building warrant and the build, carried out by vetted teams working under S&K.
Around Lochgilphead we also work in Rothesay, Dunoon and Gourock, and across the rest of Argyll and Bute. Postcode districts in and near Lochgilphead: PA30 and PA31.
What it costs in Lochgilphead
Guide prices for part single, part two-storey extensions in Scotland are around £1,880–£2,580 per m² of new floor space, including VAT. For a typical project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total), that's roughly £67,500–£93,000. 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 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) |
|---|---|---|
| Essential | £1,730–£2,380 per m² | £62,500–£85,500 |
| Standard | £1,880–£2,580 per m² | £67,500–£93,000 |
| Premium | £2,260–£3,100 per m² | £81,000–£111,500 |
Planning and building standards in Lochgilphead
In Scotland, because part of the extension is more than one storey, it is assessed under Class 1B, which needs at least 10 m to every boundary for permitted development. On most plots that is not possible, so the extension needs a householder application (£371, decided within two months). A building warrant is also needed before any work starts.
Approval in Scotland: Householder planning application: £371. Councils have two months to decide a local planning application.
Building standards: A building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks.
Design points for Lochgilphead homes
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.
Structure at the step
The first-floor wall above often sits over the new open-plan space, so it needs a steel beam or frame to carry it. Loads come down at different points than in a full two-storey design, and the engineer sizes the foundations to suit each part.
How we'd run your project
Visit by arrangement
We agree a visit to your home in Lochgilphead and any travel costs with you in writing first, then look at the structure, access and boundaries.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Technical design
We prepare the building warrant drawings, structural calculations and specification so the build price can be fixed.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.
Questions about part single, part two-storey extensions in Lochgilphead
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 have two months to decide a local planning application), 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.
Who handles building standards for a project in Lochgilphead?
We handle it as part of the project. What's needed in Scotland: a building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks. 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 part single, part two-storey extension cost in Lochgilphead?
Our guide for Scotland, which covers Lochgilphead, is £1,880–£2,580 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 £67,500–£93,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
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.
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.
Nearby
Nearby towns we cover for part single, part two-storey extensions:
Other extensions in Lochgilphead
- Rear
- Side
- Wraparound
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Lochgilphead · Part single, part two-storey extensions across Argyll and Bute
The quickest next step is a visit. We'll look at your house in Lochgilphead and give you an honest view of the options.