House Extension Plans in Cardiff

If you’re planning a house extension, you’ll need clear, accurate drawings - whether for planning permission, permitted development, or construction.

At Dennis Hellyar Architects, we specialise in preparing house extension plans for homeowners across Cardiff, helping you move from initial idea to approved design.

We also work with homeowners in Swansea, across the Vale of Glamorgan, wider South Wales, Bristol and the South West.

What you actually need

What drawings are needed for a house extension?

Most extension projects require:

  • Existing and proposed floor plans

  • Elevations

  • Site/location plans

  • Supporting information for planning

We prepare all required drawings and guide you through the process.

Our Service

Our house extension service includes:

  • Initial consultation and advice

  • Measured survey of your property

  • Concept design options

  • Planning drawings and submission

  • Ongoing support through the planning process

Cardiff - Specific

We regularly work on house extensions across Cardiff and understand the local planning requirements, including conservation areas and common residential constraints.

Cost

How much do house extension plans cost?

The cost of extension drawings depends on the size and complexity of your project.

We provide clear guidance following an initial consultation so you understand exactly what’s involved before proceeding.

Do you need an Architect?

While it’s possible to obtain basic drawings elsewhere, working with an architect ensures your extension is well-designed, compliant, and adds real value to your home.

If you’re considering a house extension in Cardiff, we can help you take the first step with clear, professional drawings.

Contact us to discuss your project.