Part single, part two-storey extensions in Aberystwyth

Quick reference for homeowners in Aberystwyth.

Postcode districts: SY24
County / area: Dyfed, Wales
Price region: Wales
Guide price: £66,000–£91,000 (£1,840–£2,530 per m²)
Approval route: It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary.
Nearest towns: Penparcau (0.9 miles), Tywyn (11.8 miles), Llanidloes (23 miles)
Distance to Llanelli: about 50.8 miles
First visit: Free, no obligation

About a part single, part two-storey extension

A part single, part two-storey extension is an extension where the ground floor is wider or deeper than the floor above, so only part of it rises to two storeys. It usually gives a large kitchen or living area with roof lights below and one bedroom or bathroom above. It is often a good way to add space while limiting the effect on neighbours.

Aberystwyth sits about 50.8 miles from Llanelli. Closer to home, Penparcau is 0.9 miles away and Tywyn 11.8 miles.

What it costs in Aberystwyth

Expect a part single, part two-storey extension in Aberystwyth to land somewhere around £66,000–£91,000 for a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total). Our Wales guide rate is £1,840–£2,530 per m², including VAT. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

Spec	Per m²	A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total)
Essential	£1,690–£2,330 per m²	£61,000–£84,000
Standard	£1,840–£2,530 per m²	£66,000–£91,000
Premium	£2,210–£3,040 per m²	£79,500–£109,500

Planning and building regulations in Aberystwyth

In Wales, a part two-storey rear extension can be permitted development if the first floor goes no more than 3 m and the ground floor no more than 4 m beyond the original rear wall, with the first floor at least 10.5 m from the rear boundary. Conservation areas and other protected areas are excluded. If the design falls outside these limits, a householder application costs £585.

Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.

Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).

Design points for Aberystwyth homes

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.

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

Free site visit
We visit your home in Aberystwyth, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Wales before drawing in detail.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
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 Aberystwyth

Do I need planning permission for a part single, part two-storey extension in Aberystwyth?

Aberystwyth is in Wales, so Wales planning rules apply. It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Which postcodes do you cover around Aberystwyth?

We cover Aberystwyth (SY24) and nearby places including Penparcau, Tywyn and Llanidloes, plus the rest of Dyfed. The first site visit is free.

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 normally decide householder applications within 8 weeks), 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.

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

Other towns near Aberystwyth:

Other extensions in Aberystwyth

All two-storey extension services in Aberystwyth · Part single, part two-storey extensions across Dyfed

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