Part single, part two-storey extensions in Llanidloes

Useful details for planning a part single, part two-storey extension in Llanidloes.

Postcode districts: SY17, SY18 and SY19
County / area: Powys, 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: Newtown (11.1 miles), Llandrindod Wells (15.9 miles), Builth Wells (21.5 miles)
Distance to Newtown: about 11.1 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.

We cover Llanidloes (SY17, SY18 and SY19) and the places around it, including Newtown (11.1 miles), Llandrindod Wells (15.9 miles) and Builth Wells.

What it costs in Llanidloes

A guide price for Llanidloes: 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). That works out at £1,840–£2,530 per m² of new floor space, including VAT at 20%. 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	£1,690–£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 Llanidloes

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 Llanidloes homes

Where to put the two-storey part

The two-storey section usually works best away from the closest neighbour, with the single-storey part on that boundary side. We test a few positions against neighbours' windows, the upstairs layout and the roof shape before choosing the one to take forward.

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

Start at your house
We come to your home in Llanidloes, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Get it approved
Once you're happy with the design we submit it to the council for Llanidloes and deal with any questions from the planning officer.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
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 Llanidloes

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

Our guide for Wales, which covers Llanidloes, is £1,840–£2,530 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 £66,000–£91,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Which postcodes do you cover around Llanidloes?

We cover Llanidloes (SY17, SY18 and SY19) and nearby places including Newtown, Llandrindod Wells and Builth Wells, plus the rest of Powys. The first site visit is free.

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

Llanidloes 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 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

Close to Llanidloes? We work across the area, including:

Other extensions in Llanidloes

All two-storey extension services in Llanidloes · Part single, part two-storey extensions across Powys

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Llanidloes.