Caswell's Premier Home Improvements

We build extensions in Caswell for people who love their postcode but hate their floor plan. Let's fix that layout.

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Specialists in Caswell House Extensions

From compact side returns in terraced homes to large wrap‑around extensions in suburban properties, we design and build Caswell house extensions that enhance space, flow and value.

We manage everything: design, planning, building regulations, groundworks, structure, and high‑quality internal finishes—delivered on time and to budget by our CITB certified team.

  • Single-storey and double-storey extensions
  • Wrap-around and side-return extensions
  • Kitchen and dining extensions
  • Conservatories & orangeries
  • Planning permission & building regs
  • Full project management
Caswell house extension services

Our House Extension Process in Caswell

A clear, step‑by‑step process from first enquiry to final handover so you always know what is happening on your Caswell project.

1. Initial Consultation & Site Survey

We visit your property in Caswell to understand how you live, your space requirements, budget and timescales. We discuss options such as single‑storey, double‑storey or wrap‑around extensions.

2. Design, Planning & Costing

Working with architects and structural engineers, we develop extension drawings, prepare planning or permitted development documentation and provide a detailed, fixed price for the build.

3. Construction Phase

Our build team manages all aspects of construction – groundworks, drainage, structure, roof, windows, electrics, plumbing, plastering and finishes – with regular updates and site meetings.

4. Handover, Snagging & Aftercare

Once complete, we walk through your new space, deal with any snags promptly and provide certificates, warranties and building control sign‑off for your Caswell house extension.

Types of Extensions We Build

Choose the right extension for your Caswell home and lifestyle

Single storey house extension in Caswell

Single-Storey Extensions

Perfect for expanding ground floor living spaces. Ideal for kitchen extensions, dining areas, or family rooms with seamless indoor-outdoor flow.

  • Kitchen extensions
  • Family room additions
  • Bi-fold doors to garden
  • Open-plan living
Double storey house extension in Caswell

Double-Storey Extensions

Maximize space with two-storey additions. Add bedrooms, bathrooms, and living areas while maintaining garden space and adding significant value.

  • Extra bedrooms
  • Additional bathrooms
  • Expanded living areas
  • Maximum value addition
Wrap around house extension in Caswell

Wrap-Around Extensions

Combine side return and rear extensions for maximum space transformation. Create spectacular open-plan living areas with abundant natural light.

  • Maximum space gain
  • Open-plan design
  • Natural light optimization
  • Complete transformation
Modern kitchen extension in Caswell

Kitchen Extensions

Transform your kitchen into the heart of your home. Modern kitchen extensions with island units, dining areas, and seamless garden access.

  • Modern kitchen design
  • Island and peninsula units
  • Dining integration
  • Garden connectivity
Conservatory and orangery extension in Caswell

Conservatories & Orangeries

Light-filled extensions that blur the boundary between indoor and outdoor living. Modern glazed extensions with excellent thermal performance.

  • Maximum natural light
  • Garden views
  • Year-round usability
  • Thermal efficiency
Loft extension with dormer in Caswell

Loft Extensions

Convert unused loft space into bedrooms, offices, or playrooms. Dormer extensions and full loft conversions with modern amenities.

  • Additional bedrooms
  • Home office space
  • En-suite bathrooms
  • Dormer windows

Why Choose Building Group for House Extensions in Caswell?

A specialist house extension contractor trusted across Caswell and the wider Swansea area for quality, safety and clear communication.

CITB Trained & Experienced Team

All trades on your Caswell house extension are vetted, experienced and follow CITB and UK building regulations. Structural work, foundations, steels and roof alterations are all signed off by qualified professionals.

Fixed, Itemised Quotations

We provide clear, itemised quotes for your extension project in Caswell – including labour, materials and allowances – so you know exactly what’s included before work begins.

Fully Insured & Guaranteed

Building Group carries full public liability and employers’ liability insurance. All major elements of your house extension are covered by written workmanship guarantees and manufacturer warranties.

Design, Planning & Building Control

From initial concept sketches to planning permission and building control sign‑off, we manage the full process for your Caswell extension so you only deal with one contractor.

Why Choose Our Caswell House Extensions

Increase Property Value

Well-designed extensions can add 15-25% to your property value, often exceeding construction cost and providing excellent ROI.

Avoid Moving Costs

Extend your current home instead of moving. Save on estate agent fees, stamp duty, legal costs, and the stress of relocating.

Better Family Living

Create the space your family needs to grow and thrive—open-plan living, additional bedrooms, and functional family areas.

Personalized Design

Custom layouts, premium materials, and finishes that reflect your style and needs—designed for Caswell homes.

House Extensions Near Me in Caswell

Looking for trusted house extension builders in Caswell and across Swansea? Our local team delivers high–quality extensions with full project management.

Local Caswell & Swansea Expertise

Because we work across Caswell and the wider Swansea area, we understand local planning policies, typical property types and what adds real value in this market.

  • Local survey and design support in Caswell
  • Planning and building control handled with your Swansea council
  • Extensions designed specifically for Caswell homes and plots
  • CITB certified trades and fully insured work

You can also browse all of our coverage areas on our House Extensions Near Me hub to see other locations we serve around Swansea.

Where We Work Around Caswell

We cover Caswell and surrounding Swansea locations, typically within a 30–40 minute drive. This keeps our teams local and our response times quick.

  • Full design & build extensions
  • Structural steel & open‑plan knock‑throughs
  • Kitchen, bathroom and utility refits
  • Planning, building regs and inspections

Our Extension Process

From initial consultation to final handover—complete delivery in Caswell

Planning & Design Phase

  • Initial Consultation: Free site visit to assess your property and discuss your extension goals
  • Design Development: Architectural drawings and 3D visuals tailored to your home
  • Planning Permission: Full application service including drawings and submission
  • Building Regulations: Technical drawings and building control approvals
  • Detailed Quote: Transparent pricing with full material and labour breakdown

Construction Phase

  • Project Management: Dedicated PM coordinating all trades and timelines
  • Professional Trades: CITB certified builders, electricians, plumbers and specialists
  • Quality Control: Regular inspections and quality checks throughout
  • Progress Updates: Weekly reports with photos and timeline updates
  • Final Handover: Warranties, certificates and maintenance guides

Design & Planning

Professional architectural services

Planning Permission

Full application and approval service

Expert Construction

CITB certified professional trades

Caswell & Swansea Coverage

House Extensions Across the Region

Our extension teams operate across Caswell and neighbouring areas, bringing local knowledge and expertise to every project.

We provide comprehensive house extension services throughout Caswell and the wider Swansea area, including Caswell, surrounding Swansea villages and suburbs.

Our local Caswell team understands the specific planning requirements, building regulations, and architectural styles common to properties in this area. We work closely with Swansea planning departments to ensure smooth project approval.

Whether you're in Caswell town centre or the surrounding suburbs, we deliver the same high standards of craftsmanship and project management that have made us the region's trusted extension specialists.

Caswell and Swansea extension service coverage

Caswell House Extension Reviews

Recent feedback from homeowners in Caswell and across Swansea.

★★★★★

“Great communication, clear pricing and no surprises. We’d happily recommend Building Group for extensions anywhere in Swansea.”

Rebecca T – Swansea
★★★★★

“Honest advice and quality workmanship. Our extension in Caswell was completed within budget and looks amazing.”

John P – Swansea
★★★★★

“Building Group transformed our home in Swansea. The new space is exactly what we wanted. Highly recommended.”

The Clarke Family – Caswell
★★★★★

“Second time we’ve used Building Group – loft conversion first, then a rear extension in Caswell. Both projects were spot on.”

James K – Caswell

Read more detailed feedback from our house extension clients.

See All Reviews

Recent House Extension Projects Near Caswell

A selection of recent house extensions we have completed across Swansea, including projects close to Caswell.

Kitchen Extension & Open‑Plan Living

Single‑storey rear extension with structural steel installation, new kitchen, rooflights and bi‑fold doors to create a modern, open‑plan family space for a home near Caswell.

Double‑Storey Side Extension

Two‑storey side extension providing an additional bedroom, en‑suite and extended ground floor living area for a property in the wider Swansea area.

Wrap‑Around Extension

Full L‑shaped wrap‑around house extension with new utility, WC, kitchen‑diner and upgraded facade, designed to maximise the plot and add long‑term value.

View more of our house extension projects

Caswell House Extension FAQs

Clear answers to the most common questions homeowners in Caswell and Swansea ask us about planning, costs and timelines for house extensions.

Not always. Many single-storey rear extensions in Caswell can be built under permitted development, which means you don’t need a full planning application. However, this depends on:

  • The overall depth and height of the extension
  • Whether your home has already been extended in the past
  • If the property is terraced, semi-detached or detached
  • Whether you live in a conservation area or have an Article 4 direction

Before any design is finalised, we check the latest Swansea council guidance, measure your existing property and confirm whether your project is permitted development or needs a planning application. If an application is required, we handle drawings, submission and liaison with the planning officer for you.

Costs vary depending on size, specification and access, but as a guide for Caswell and the wider Swansea area:

  • Single-storey extensions typically start from around £1,500–£2,500 per m²
  • Double-storey extensions usually range from £1,800–£3,000 per m²
  • High-end finishes, glazing walls or complex steelwork will increase the budget

We always carry out a detailed survey and provide a fixed, itemised quotation so you can see exactly what is included: groundworks, structure, roof, windows/doors, internal finishes and professional fees where required. Value engineering options can be discussed if you have a strict budget to work to.

A typical single-storey extension in Caswell takes around 8–12 weeks on site, while larger or double-storey projects can take 12–16+ weeks. The programme usually follows these stages:

  • Groundworks and foundations
  • Walls, steelwork and structural alterations
  • Roof structure and covering
  • Windows, doors and making the extension watertight
  • First fix services (electrics, plumbing, heating)
  • Plastering, second fix and finishes

Before we start on site, you’ll receive a clear project programme with key milestones so you always know what is happening and when each phase is due to be completed.

In most projects, yes. Many clients in Caswell stay in their homes throughout the build. We plan the works so that:

  • Dust and debris are controlled with temporary screens and protection
  • Safe access routes are maintained at all times
  • Noisy or disruptive works are grouped together where possible
  • Kitchen and bathroom facilities remain usable for as long as we can

If a short period of alternative accommodation is advisable (for example during major knock-through works), we will explain this during the planning stage so you can factor it into your arrangements.

In most cases, a well-designed extension in Caswell adds significant value as well as improving day-to-day living. Estate agents in Swansea typically see the best returns from:

  • Creating larger open-plan kitchen / family spaces
  • Adding extra bedrooms and a bathroom on upper floors
  • Improving natural light with good glazing and layout

We can work with you to balance build cost against likely value uplift, so your project makes sense both as a home improvement and as an investment.

Based locally in Swansea, serving homeowners in and around Caswell. Typical project radius: ~25–30 miles from Caswell.

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