House Extensions in Cardiff

Unlock the space your home already has with a thoughtfully designed extension.

As a family-run company with 40+ years’ experience, R.E.G Construction Limited delivers end-to-end extension projects across Cardiff and South Wales - from initial design and permissions through to a flawless finish.

Why extend your home with R.E.G?

Whether you’re planning a larger kitchen-diner, a new bedroom, home office or a full wraparound, our in-house team manages every trade and every stage.

We work closely with architects and local authorities, keep communication clear, and provide a detailed programme of works with firm start/finish dates and a staged payment schedule.

• Design-led approach with practical cost guidance
• All trades in-house: groundworks, bricklaying, carpentry, roofing, plumbing & electrics, finishing
• Transparent timelines and site management
• Quality craftsmanship recognised in Grand Designs magazine

Our process: clear, managed, end-to-end

1. Consultation & Feasibility: We discuss your goals, budget and timeline, and advise on the best route forward.
2. Survey & Concept Design: Measured survey, concept layouts and options to match your brief.
3. Planning & Building Control: Guidance on permitted development vs. planning permission and full handling of submissions.
4. Detailed Quotation: Itemised pricing and a programme of works that sets expectations from day one.
5. Construction & Coordination: On-site organisation, regular updates and tidy, respectful working practices.
6. Finishing & Handover: Snagging, certifications and a quality finish ready to enjoy.

Note: Planning requirements vary by property and area. We’ll confirm what’s needed for your specific project.

Specification and finishes

From structural steel and insulation to glazing, heating and bespoke joinery, we specify durable, compliant materials that perform and look great.

Our kitchen and bathroom fitting, decorating and flooring teams ensure your extension feels integrated with the rest of your home.

Prefer a phased approach? We can handle shell-only construction or deliver a turnkey finish - you choose the level of involvement that suits you.

Get in touch with R.E.G Construction Limited to book a free initial consultation. We’ll discuss ideas, timelines and budget, and provide a clear path from design to completion.