Where to Start with Your Home Extension
If you’re planning a home extension, a bit of early guidance can make all the difference. Here’s how to get started, understand the process, and avoid common mistakes when turning your ideas into a successful project.
Extending or remodelling your home is an exciting opportunity to create space that works better for you and your family. It can also feel daunting knowing where to begin or who to speak to first.
This guide takes you through the early stages of planning a home extension, from shaping your brief and setting a budget to understanding permissions and when to involve an architectural designer. It’s a practical starting point to help you move forward with confidence.
STEP ONE: GET CLEAR ON WHY YOU'RE DOING THIS
Before diving into design ideas or calling builders for quotes, take a moment to ask yourself: What’s the real reason I want to extend?
• Do you need more space because of a growing family?
• Are you craving better flow and light in your kitchen/living area?
• Do you want to stay put but make your home feel “new”?
Understanding your core motivation helps you stay grounded through all the decisions that come later. A great design starts with knowing what matters most.
STEP TWO: THINK FUNCTION FIRST, STYLE SECOND
Pinterest and Instagram are full of stunning spaces, but your home needs to work for you. Before you get caught up in rooflines, window shapes or paint colours, focus on how the space should function.
Some good prompts:
• What’s currently not working in your home?
• When do you feel frustrated by the layout or flow?
• Where do you need more light, warmth, or storage?
A skilled architectural designer will translate these insights into a layout that works beautifully and feels good to live in. Style will follow naturally once the bones are right.
STEP THREE: BE REALISTIC ABOUT BUDGET
A lot of disappointment in extension projects comes from mismatched expectations around cost. It’s much better to work with a rough budget early on, even if it changes later.
Typical 2025 ballpark figures:
• Build cost: £1,700 – £3,000 per m² (depending on spec)
• Kitchen fit-out: £15,000 – £30,000+
• Professional fees and approvals: 10–18% of build cost
Don’t forget to allow for things like glazing, bathrooms, landscaping, and finishes – not just bricks and mortar.
Tip: If you don’t know your budget, try working backwards. How much would you feel comfortable investing overall?
STEP FOUR: DON’T WORRY IF YOU DON’T HAVE ALL THE ANSWERS YET
Lots of clients feel unsure about when to get in touch. They might say:
• “We’re not ready yet, we haven’t figured it all out.”
• “We don’t want to waste anyone’s time.”
• “We just need a builder really, don’t we?”
Here’s the truth: The earlier you speak to an architect or architectural designer, the better. We’ll help you shape your brief, clarify your goals, and avoid design decisions that could cost you more later.
STEP FIVE: UNDERSTAND WHAT COMES FIRST
Every extension project has its own route, but here’s a typical early-stage journey:
Initial chat and consultation – We listen to your ideas and give honest early advice
Briefing and quote – We shape a scope of work and provide a fixed-fee quote
Survey and design – We measure up, develop concepts, and work with you on the layout
Planning or permitted development checks – We advise on what permissions are needed
Technical design and regulations – This stage comes later, once the layout is locked in
Not sure if you need planning permission? We’ll advise you, and we often apply for Certificates of Lawfulness even when formal planning isn’t required.
COMMON EARLY PITFALLS TO AVOID
• Jumping straight to a builder without clear plans or approvals
• Not sharing your budget because you’re worried it’ll limit creativity (it won’t – it helps)
• Overthinking the final look before working out how the space should work
• Assuming it’s all about square metres – great design is about flow, light and feel, not just size
FINAL THOUGHTS: START WITH CONVERSATION, NOT COMMITMENT
A good first step is simply having a conversation. At Angus Design, we offer friendly, no-pressure consultations to help you understand what’s possible, what it might cost, and what to expect from the process.
If you’re thinking about a home extension, even if you’re just gathering ideas, we’d love to hear from you. It’s never too early to get professional advice.
