Planning an Extension? Here’s What to Know Before You Start
Extending your home is one of the most rewarding ways to create more space without moving — but it’s also one of the most complex. Whether you’re adding an extra bedroom, extending your kitchen, or creating a sunlit studio, every detail counts.
At Formery Studio, we believe a successful home extension begins long before construction starts. It’s about clarity — knowing your goals, timeline, budget, and the approval process inside out. That preparation is what turns a stressful renovation into a smooth, exciting transformation.
Here’s everything you need to know before planning your extension.
Start with Your Why
Before sketching floor plans or scrolling through Pinterest, step back and ask: Why are you extending?
Is it to add more living space, improve flow, increase property value, or future-proof your home? Your “why” guides every decision that follows.
Example:
If your goal is to create a better connection between indoor and outdoor spaces, focus on layout and natural light.
If it’s about accommodating family growth, prioritize functionality and storage.
Tip: Write your goals down. Keep them visible throughout the design process — they’ll anchor your decisions when the process feels overwhelming.
Define Your Brief Early
A clear brief is the foundation of every great extension. It’s how you communicate your vision to your architect or designer.
A good brief includes:
Your goals and lifestyle needs
Number and type of rooms you want to add
Preferred materials and style
How you want the new space to connect with existing areas
Pro insight: At Formery, we encourage clients to include photos of spaces they love, along with notes about what works (and what doesn’t) in their current layout. Visual cues make communication faster and clearer.
Understand Your Timeline
Extensions can take longer than expected — and for good reason. The process includes design, documentation, council approvals, tendering, and construction.
Typical timeline example (for planning only):
Design concept: 4–6 weeks
Council or building approvals: 6–12 weeks
Construction: 3–6 months (depending on size and complexity)
To stay on track, always build in contingency time for approvals or unexpected delays.
Pro tip: The earlier you involve your architect or designer, the smoother the process will be. A well-prepared design team can anticipate red flags before they turn into roadblocks.
Budget Realistically
Budgeting for an extension is about more than construction costs. Many homeowners underestimate the “invisible” expenses — like design documentation, permits, utilities, and finishes.
A basic extension budget should include:
Design & documentation fees (architecture, interiors, engineering)
Permit and council approval costs
Construction costs (materials, labor, site prep)
Contingency fund (10–15% recommended)
Common mistake: Homeowners often finalize their design before confirming build costs. Always align your design scope with your budget early on to avoid surprises later.
Know Your Local Regulations and Approvals
Before any work begins, you’ll need to understand your local building and planning requirements.
Depending on your area, you may need:
Planning permit: For changes that affect the property’s footprint or external appearance
Building permit: To ensure the construction meets safety codes
Heritage or zoning checks: If your property has restrictions
At Formery, we help clients navigate this stage — coordinating with local councils and consultants so approvals are handled efficiently.
Avoid These Common Pitfalls
Even well-intentioned projects can go off track. Here are the most common issues we see — and how to prevent them:
Pitfall
How to Avoid It
Skipping pre-design planning
Start with a detailed brief, not just an idea.
Ignoring site constraints
Get a site analysis early — it affects cost, structure, and orientation.
Overlooking budget contingencies
Add 10–15% to cover unexpected costs.
Changing your mind mid-build
Lock in major design decisions before construction.
Not considering natural light
Design for both aesthetics and comfort.
The Power of Collaboration
An extension isn’t just about adding space — it’s about adding value. That means every addition should integrate seamlessly with your existing architecture and interior flow.
When architects and interior designers work together, the extension doesn’t look “tacked on.” It feels intentional, balanced, and timeless.
At Formery, our integrated design process ensures that your extension not only meets your practical needs but also enhances your home’s personality and performance.
Prepare for the Journey
Extending your home is a big step — but it’s also an opportunity to reimagine the way you live. With the right planning, professionals, and patience, the process can be deeply rewarding.
Start with clarity, align your goals, and collaborate with experts who understand both the architectural and human side of design.
Because when your home grows with you — thoughtfully and intentionally — every square meter tells your story.
💡 Ready to Start Planning?
Book a one-on-one consultation with Formery Studio to discuss your project vision and next steps.
Let’s create an extension that feels seamless, functional, and truly yours.