10 Things to Consider Before Starting Your Home Extension

Planning a home extension is an exciting opportunity — whether you’re adding space for a growing family, creating a light-filled kitchen-diner, or designing a retreat that connects you to your garden. But before you dive in, there are some key things to think about that will save time, money, and stress later on.

Here are 10 essentials every homeowner should consider before starting an extension project:

1. Define Your Goals

Start by asking: What do I want from this extension? More space, better flow, improved light, or a connection to the outdoors? Having a clear vision will guide the design and decision-making process.

2. Set a Realistic Budget

Extensions are a big investment. Factor in construction, design fees, planning applications, VAT, and a contingency (usually 10–15%). Being realistic about costs from the outset avoids nasty surprises.

3. Understand Planning Permission

Not every extension requires full planning permission, but many do. Even permitted development has strict rules on size, height, and location. A professional can advise on the right route and help prepare a strong application.

4. Consider Your Neighbours

Extensions can affect neighbouring properties through light, views, or shared boundaries. Early conversations with neighbours can smooth the process and avoid objections during planning.

5. Respect the Existing Building

The best extensions enhance what’s already there. Think about how materials, proportions, and rooflines tie in (or contrast) with your existing home to create a design that feels intentional.

6. Think About Light

Natural light is one of the most transformative elements of good design. Consider orientation, glazing, and rooflights to brighten your space and reduce reliance on artificial lighting.

7. Plan for Energy Efficiency

An extension is an opportunity to improve your home’s performance. High-quality insulation, airtightness, and efficient glazing will make the new space warmer, cheaper to run, and more sustainable.

8. Design for Flow

An extension shouldn’t just add square footage — it should improve how you use your whole home. Think carefully about circulation, connections between rooms, and how new and old spaces link together.

9. Choose the Right Team

An experienced architect and builder will guide you through design, planning, and construction. Look for professionals with a strong track record in residential projects, and make sure you feel comfortable communicating with them.

10. Future-Proof Your Design

Think long-term. Could the new space adapt as your lifestyle changes? Whether it’s accommodating a growing family, working from home, or future accessibility needs, flexibility is key.

Final Thoughts

A home extension can completely transform how you live — but only if it’s carefully planned. By considering these ten essentials before you begin, you’ll be well on your way to creating a space that’s beautiful, practical, and tailored to your life.