House Extensions in Anglesey
If you are planning a home extension, choosing the right builder is essential. AJ Building Contractors delivers high-quality house extensions in Anglesey that homeowners can trust, backed by over 50 years of combined construction experience. Based in Llanerchymedd, we design and build extensions that add space, improve layout, and increase long-term property value.
As experienced local builders, we manage every stage of your extension project with clear communication, careful planning, and consistent workmanship. From initial groundworks through to completion, our team provides a fully managed service tailored to your home and your needs.
Why Homeowners Choose Us For House Extensions
- Family-run building company with local accountability
- Over 50 years of combined construction experience
- Majority of workis completed in-house for quality control
- Qualified site management and safety-led approach
- Free, detailed estimates with clear pricing
- Experienced in structural and complex extension work
- Highly rated by local customers


Each extension is tailored to suit the existing property structure and the homeowner’s requirements.
Types of House Extensions We Build
We deliver a wide range of house extensions. Common requests include:
Single Storey Extensions
Ideal for expanding kitchens, dining areas, or living spaces. Single-storey extensions are a popular way to improve layout and functionality without moving home.
Double Storey Extensions
A practical solution for growing families who need additional bedrooms, bathrooms, or living areas while maximising available space.
Rear Extensions
Rear extensions create open plan living areas and connect indoor spaces with gardens, improving light and flow throughout the home.
Garage Conversions
We convert unused garages into functional living spaces such as home offices, playrooms, or additional bedrooms as part of extension projects.
What Is Included in Our House Extension Service
Our house extensions in Anglesey are fully managed and include all major construction elements required to complete your project safely and efficiently.
This includes:
- Groundworks and excavation
- Drainage installation
- Foundations and structural work
- Brickwork and blockwork
- Roofing construction
- Joinery and carpentry
- Internal structural alterations
- Finishing works
We complete the majority of work in-house. Plumbing and electrical installations are carried out by trusted subcontractors to ensure compliance and safety.

Full Project Management From Start to Finish
Successful house extensions rely on planning and coordination. Every extension we build is overseen by a qualified Site Manager, ensuring work is completed safely, efficiently, and in the correct sequence.
Our project management approach includes:
✔ Clear schedules and realistic timelines
✔ On-site coordination and supervision
✔ Health and safety compliance throughout
✔ Regular progress updates
✔ Clear communication at every stage
This structured approach helps reduce delays, minimise disruption, and maintain quality standards throughout the build.
Structural Expertise and Safety-Led Construction
Extending your home is a major investment. Our role is to make the process structured, predictable, and stress-free. As specialists in house extensions Anglesey, we focus on projects where careful integration with the existing property is critical.
Many house extensions involve complex structural changes. Our team has extensive experience handling structural work, including steel installation and load-bearing alterations.
Tony is qualified in mobile crane operations and is trained to calculate load sizes and crane requirements. This expertise is particularly valuable for extensions requiring steel beams or restricted access.
We also have experience working in regulated environments such as sites near railways and canals. This background ensures your extension is completed with a strong focus on safety, planning, and compliance.

Frequently asked questions

Do you manage the entire extension project?
Yes. We provide full project management for all house extensions in Anglesey, coordinating every stage from groundworks to completion.
Do you complete the work in-house?
The majority of construction work is completed in-house. Plumbing and electrical work is carried out by trusted subcontractors.
Can you handle structural alterations?
Yes. We regularly complete structural work, including steel installation and internal alterations as part of extension projects.
Do you provide free quotes?
Yes. We offer free, no-obligation estimates with clear pricing and realistic timelines.
How long does a house extension take?
Timescales vary depending on size and complexity. We provide a clear schedule before work begins and keep you updated throughout the build.
Why Choose AJ Building Contractors for House Extensions
Choosing the right builder makes all the difference. Homeowners choose us because we offer:
- Extensive construction and joinery experience
- Qualified site management
- Strong focus on safety and compliance
- Clear communication and honest pricing
- Proven local reputation
We take pride in delivering extensions that enhance homes and provide lasting value.

Get a Free Quote for Your Home Extension in Anglesey
If you are planning a home extension and want experienced local builders you can rely on, AJ Building Contractors are ready to help. Our team will guide you through the process and deliver a well-managed, high-quality extension built to last.
Telephone: 01248661401
Mobile: 07414296131
E-mail: info@ajbuildersltd.uk
Address: 15 Bryncir Estate, Llannerchymedd, Anglesey, LL71 8EQ.
If you would like to send us an enquiry please fill out the below form with your contact info and message.
