Need more space but love where you live? A home extension is often the perfect solution. Whether it’s a new bedroom, a larger kitchen, or a second storey, an extension can give your family room to grow—without the stress of moving.
But here’s the deal: the success of your project depends on the builder you choose. The right team will deliver quality work, clear communication, and peace of mind from start to finish. The wrong one? Let’s just say your dream reno could turn into a costly headache.
This guide will help you choose the right home extension builders with confidence—no stress, no surprises.
What to Look for in a Home Extension Builder
Licensing and Insurance
Let’s start with the basics. A reputable builder will always be properly licensed and insured. That means:
- A valid builder’s license for your state or territory
- Public liability and construction insurance
- Builders warranty insurance (if your project qualifies)
If they can’t show you paperwork, walk away.
Experience That Matches Your Vision
Not all builders are created equal. Look for a team with proven experience in your type of extension. Are you adding a second storey? Converting a garage? Building a granny flat out back?
Ask to see past projects—and if they’ve done something similar to yours, even better. An experienced builder knows what can go wrong (and how to avoid it).
Transparent Quotes and Detailed Contracts
If a quote is vague or the contract feels rushed, it’s a red flag. A solid home extension builder will give you a detailed quote covering:
- Scope of work
- Inclusions and exclusions
- Labour and material costs
- Payment schedule
- Estimated timeline
If something’s missing, assume it’s not included. Don’t rely on verbal promises—get everything in writing.
Clear Communication
From the first call to the final walkthrough, you want a builder who’s responsive, respectful, and upfront. Good communication makes the difference between a smooth experience and a stressful one.
Watch how they respond to your questions. Do they explain things clearly? Keep appointments? Return calls? The way they handle the early stage says a lot about how they’ll handle the whole build.
Happy Clients
Reviews matter. Testimonials and word-of-mouth referrals say more than any brochure ever could. Ask for references and—if possible—speak directly to past clients.
Common Types of Home Extensions
Every home and family is different. Here are a few popular extension types you might consider:
Rear (Ground Floor) Extension
Perfect for adding more space to your living room, kitchen, or dining area. Great if you have backyard space to build out into.
Second-Storey Addition
Build up, not out. Ideal for properties with limited land space or strict boundary setbacks. Adds significant value to your home—but expect more structural work.
Garage Conversion
An underused garage can become an extra bedroom, office, or granny flat. These are often quicker and more affordable than full-scale builds.
Granny Flat or Studio
A separate unit on your block—great for elderly parents, adult kids, or rental income. Regulations vary, so make sure your builder knows the local rules.
How Much Will It Cost?
Costs vary based on location, design, materials, and builder—but here’s a general guide:
- Ground Floor Extension: $1,800 to $4,000 per sqm
- Second Storey Addition: $2,500 to $4,500 per sqm
- Bathroom/Kitchen Additions: Add $15,000 to $30,000 per room
- Granny Flat: $70,000 to $150,000+ depending on size and finish
- Deck/Outdoor Extension: $200 to $500 per sqm
Always include a 10–15% contingency for unexpected costs. And remember: the cheapest quote isn’t always the best.
What’s the Timeline?
Here’s a rough breakdown:
- Design + Council Approvals: 1 to 3 months
- Construction:
- Small/standard extensions: 3 to 6 months
- Complex or second-storey: 6 to 12 months
- Garage conversions: 2 to 3 months
- Small/standard extensions: 3 to 6 months
The smoother your planning and approvals, the faster you can build. Lock in decisions early (tiles, fittings, fixtures) to avoid delays down the line.
Red Flags to Watch For
Even with so many great builders out there, a few dodgy ones still slip through. Avoid headaches by watching for:
- Vague quotes or verbal-only estimates
- Pressure to sign quickly
- No license or insurance
- Poor online presence or bad reviews
- Reluctance to provide references
- Unclear or missing contract details
- Overly large deposit requests
- Constantly shifting timelines
If your gut says no—listen to it.
Should You Choose a Design-and-Build Company?
Some builders offer design and construction under one roof. That means they can help you:
- Finalise the layout
- Handle council approvals
- Suggest materials and finishes
- Manage the entire project from start to finish
This can streamline the process, especially if you haven’t hired an architect yet. Just be sure the company has a solid design portfolio and good communication systems.
Why Homeowners Choose Scope Building Group
We know you’ve got plenty of builders to choose from. So why pick Scope?
Because we’re not just about building—we’re about trust. We’re the team that shows up on time, answers your calls, and treats your home like our own.
We’re fully licensed and insured, with experience across all extension types: second storeys, ground floor builds, garages, and granny flats.
And we’re local. We understand the council rules, the permits, and the best materials for Australia’s climate. Our team works with you from day one to get it right—and get it done.
Get It Done Right with Scope Building Group
At Scope Building Group, we know terracotta roofs inside and out. From Federation renovations to modern new builds, our licensed team handles everything — sourcing, installation, repairs and advice.
We don’t just install roofs. We build long-term peace of mind.
✅ Local Sydney experience
✅ Clean, on-time installation
✅ Honest pricing, no surprises
✅ Fully licensed and insured
Ready to make the switch? Contact Scope Building Group today and discover how we can help you transform your roof or call 02 9736 2273 / 1300 492 013 for a consultation.
