Adding a house extension can really make a big difference to your home’s functionality and value. But a successful house extension requires planning and thought. This guide will take you through the steps to plan a house extension so it all runs smoothly.

House extensions are a great way to add more space and improve your home without needing to move. Whether you want a new bedroom, an extended kitchen or a home office, planning a house extension involves several key steps. This guide covers it all from initial thoughts to final touches.

1. Assess Your Needs and Goals

Start by defining why you want to extend your home. Ask yourself:

  • What is the main purpose of the extension (e.g. new bedroom, bigger kitchen, home office)?
  • How will the extension improve your daily life?
  • What are your long term plans for the property?

Having clear goals will help you make decisions throughout the planning and building process.

2. Set a Budget

A realistic budget is essential. Consider all costs:

  • Design and architectural fees
  • Planning permission (if required)
  • Build costs
  • Materials
  • Contingency for unexpected expenses

Make sure your budget matches your financial situation and has some wiggle room.

3. Research Planning Permissions and Regulations

Depending on where you live you may need planning permission for your extension. Research local building regulations and zoning laws to find out:

  • Do you need planning permission
  • The size and height restrictions on the extension
  • Impact on adjacent properties

It’s best to check with your local council or hire a professional to make sure you comply.

4. Hire an Architect or Designer

An architect or designer can turn your ideas into drawings. They will:

  • Create design options that fit your needs and budget
  • Make sure the extension matches your existing home
  • Help with planning permissions and building regulations

Choose someone with experience in residential extensions and a portfolio that matches your style.

5. Create Detailed Plans

Work with your architect to create drawings. Consider:

  • Layout: How the new space will connect to the existing building
  • Light: Natural light through windows, skylights and open spaces
  • Functionality: Does the space meet your practical needs
  • Aesthetics: How the extension will look with your home

These drawings will be used to get quotes and planning permission.

6. Get Necessary Permissions

Submit your drawings to the local planning authority (if required) and get the necessary permissions. This will take time so factor it in to your schedule.

7. Choose a Builder

Select a reputable builder, such as local trades UK, with experience in house extensions. Get multiple quotes and check references. A good builder will:

  • Provide a detailed quote and timeline
  • Has a history of completing projects on time and on budget
  • Can show you examples of previous work

8. Construction Phase

Once you have a builder, plan the construction phase. This includes:

  • Scheduling: A timeline for each stage of the project
  • Communication: Regular updates and meetings with your builder
  • Logistics: How the build will impact your daily life (e.g. temporary living arrangements, noise and access)

9. Monitor Progress

Stay involved throughout the build. Visit the site regularly and communicate with your builder to ensure:

  • Work is on track
  • Issues are fixed promptly
  • Changes are documented and agreed upon

10. Final Inspections

Once the build is complete, focus on the final details:

  • Inspect the work: Is it what you expected and meets building codes
  • Fix any snags: Work with your builder to sort out any minor issues
  • Get a completion certificate (if required): This confirms the work meets local regulations


House extensions can be a complex process but with these steps you’ll be well prepared, stay on budget and get what you need. From setting goals and budgets to hiring the right people and monitoring progress, each stage is important for a successful extension. With planning and execution, your house extension will give your family the extra space and functionality they need.