Two-storey extensions in Treorchy
Everything for a two-storey extension in Treorchy, in one place: types, guide prices for Wales, the approval rules in Wales and how to get started.
Treorchy at a glance
- Postcode districts
- CF42
- Area
- Mid Glamorgan, Wales
- Price region
- Wales
- Nearest towns
- Pentre (0.7 miles), Rhondda (2.4 miles), Ferndale (2.5 miles), Tonypandy (3.4 miles)
- Distance to Rhondda
- about 2.4 miles
- Approvals
- Two-storey rear: ground floor up to 4 m, first floor up to 3 m and 10.5 m from the rear boundary. Some two-storey side extensions can be permitted development.
Around Treorchy we also work in Pentre, Rhondda and Ferndale, and across the rest of Mid Glamorgan. Postcode district in and near Treorchy: CF42.
Extensions available in Treorchy

Two-storey rear extensions
From £51,500 in Treorchy. Free visit to firm it up.
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Two-storey side extensions
Design, approvals and build for Treorchy homes. Guide from £79,000.
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Two-storey wraparound extensions
For homes in Treorchy: typical guide from £111,000.
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Part single, part two-storey extensions
For homes in Treorchy: typical guide from £66,000.
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Extensions over a garage
Our Wales guide starts at £29,000 for this type.
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First-floor extensions
Guide from £23,000 in Treorchy, including VAT.
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Two-storey extensions for semi-detached houses
Our Wales guide starts at £51,500 for this type.
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Two-storey extensions for detached houses
Our Wales guide starts at £79,000 for this type.
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Kitchen extensions with bedrooms above
Our Wales guide starts at £51,500 (before kitchen units) for this type.
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Extra bedroom and en-suite extensions
Our Wales guide starts at £51,500 (plus en-suite) for this type.
Learn moreWhich type suits your house?
The boundaries usually decide it. Two-storey work close to a neighbour needs careful design for light and privacy, so at the visit in Treorchy we measure distances to every boundary before suggesting a type.
Also available in Mid Glamorgan
- Two-storey front extensions
- Two-storey extensions for end-of-terrace houses
- Two-storey annexe extensions
- Garage conversions with a room above
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Rules for Treorchy
Treorchy is in Wales. Two-storey rear: ground floor up to 4 m, first floor up to 3 m and 10.5 m from the rear boundary. Some two-storey side extensions can be permitted development. Householder planning application: £585. Councils normally decide householder applications within 8 weeks.
The full Wales rules explained
Questions about extensions in Treorchy
Do you cover Treorchy?
Yes. We cover Treorchy (CF42) and the surrounding area, including Pentre and Rhondda. The first site visit is free.
What does a two-storey extension cost in Treorchy?
Using our Wales guide, a two-storey rear extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) is about £51,500–£69,500 including VAT. An extension over a garage is about £29,000–£42,000.
Which other places near Treorchy do you cover?
Everywhere around it, including Pentre (0.7 miles), Rhondda (2.4 miles) and Ferndale (2.5 miles), and the rest of Mid Glamorgan.