Rear Extensions in South Wales
A rear extension is the most common form of home extension — and the simplest planning route. We build single-storey rear extensions up to 6m on detached and 4m on semi-detached / terraced homes under permitted development, with full design-and-build including aluminium bifolds, sliders and lanterns. Most single-storey rear extensions complete in 8–14 weeks.
Benefits
- Simplest Planning Route: Many single-storey rear extensions are permitted development — no full planning application needed.
- Opens onto the Garden: Bifolds, sliders or French doors connect the new room directly to the garden.
- Design-and-Build Service: Architect, structural engineer, Building Regs and the full build — one team.
- Premium Glazing Included: Aluminium bifolds, sliders and lanterns part of the original quote — not an upsell.
- Adds Real Family Space: 15–35 m² of properly built, fully insulated living space straight out the back.
- Fixed Written Quote: Itemised stage-payment pricing — no surprise costs.
Our rear extensions range
- Single-Storey Rear Extension: Classic rear build — kitchen-diner, lounge or family room out the back.
- Double-Storey Rear Extension: Two floors of new space — bigger living downstairs, extra bedroom upstairs.
- Rear Extension with Bifolds: Full-width aluminium bifold doors opening onto the garden.
- Rear Extension with Lantern: Flat-roof extension topped with a large glass lantern for dramatic light.
Frequently Asked Questions
Do I need planning permission for a rear extension?
Many single-storey rear extensions are permitted development under the larger home extension scheme — up to 6m on detached, 4m on semi/terraced. Two-storey rears require full planning. We confirm before quoting.
How long does a rear extension take?
Single-storey rears typically complete in 8–14 weeks. Two-storey rears take 14–22 weeks.
How much does a rear extension cost?
Single-storey rears typically run £1,800–£2,800 per m². Two-storey rears run £2,200–£3,200 per m² of new floor area. Fixed quotes after survey.
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Get a fixed-price quote within 24 hours. Free home survey. 10-year guarantee. Call 02920 860894 or request a callback.