The 5 Most Common Mistakes Homeowners Make When Planning an Extension

Planning a home extension is exciting—it’s your chance to create more space, add value, and design a home that truly works for your lifestyle. But it’s also a big investment, and there are some easy-to-avoid mistakes that can derail your project.

Here are the five most common pitfalls we see homeowners make:

1. Starting Without a Clear Brief

Jumping straight into drawings without first defining your priorities can lead to confusion, extra costs, and a design that doesn’t fit your needs. Think about how you live, what spaces frustrate you, and what you want the extension to achieve.

2. Underestimating Budget & Build Costs

It’s tempting to assume an extension will cost less than it really does. Quality design, planning requirements, and construction costs add up quickly. Setting a realistic budget from the start saves disappointment later.

3. Forgetting the Big Picture

An extension shouldn’t just ‘stick out’ the back—it should improve the flow of your whole home. Consider how it connects to existing rooms, daylight, garden access, and storage.

4. Overlooking Permissions & Regulations

Planning permission, listed building consents, and Building Regulations are complex. Skipping this step or leaving it too late can cause major delays. An architect can guide you through the right approvals.

5. Choosing Builders Too Soon

It’s risky to get quotes before you have proper drawings and specifications. Builders need clear information to price fairly—otherwise you risk low quotes that balloon during construction.

✅ Final Thought:
The best way to avoid these mistakes is to work with a professional from the beginning. An architect brings clarity, creativity, and technical expertise—helping you save time, money, and stress while designing a home you’ll love.

👉 Ready to start? Book a consultation with us to explore your ideas.