Everything You Need to Know About Ground-Floor Extensions on the Sunshine Coast

July 28, 2025

I’ve been researching what it takes to extend a house on the Sunshine Coast, QLD – specifically a ground-floor extension for my four-bedroom brick home. I want to share what I’ve learned about the key considerations, local council regulations, costs, and some recommended builders. Here’s a summary of what I found.

Deciding on a Ground-Floor Extension: Key Considerations

When I considered a house extension, I debated between going up (second storey) or out (ground floor). In my case, I decided on a ground-floor extension. Here are some key things I learned:

  1. Site Coverage: The Sunshine Coast Council limits how much of your property can be covered by buildings. For residential properties, it’s usually 50%. If your house already covers a lot of the land, you may need special approval to extend beyond that. Luckily, I have enough space to build out.
  2. Setbacks and Space: The council also sets rules on how close to boundaries you can build. Generally, you need to stay 6m from the front boundary and 1.5m from side and rear boundaries. Any closer, and you’ll need council permission.
  3. Foundation & Terrain: For ground-floor extensions, you’ll need to pour a new slab or footings. If your land is sloped, additional engineering might be required. My property is flat, so I’m in the clear.
  4. Design Harmony: It’s important that the extension blends with the existing house. I plan to use brick veneer walls to match my existing home and keep the design simple. Avoiding fancy or complex designs helps keep costs in check.
  5. Ground vs. Second Storey: A ground-floor extension tends to be cheaper and simpler than adding a second storey, which involves reinforcing the existing structure, installing a staircase, and other complexities.

Sunshine Coast Council Regulations and Approvals

Navigating council rules sounded intimidating at first, but once I looked into it, it was pretty straightforward. Here’s what I found:

  1. Building Approval: Any structural changes to your house require building approval. This is typically handled by a private certifier. Make sure your plans meet council codes before you start.
  2. Setbacks & Height: You must adhere to setback rules (6m from the front, 1.5m from the sides). The height cap for most residential zones is 8.5m, which is relevant if you’re considering a second-storey addition. Ground-floor extensions usually don’t have height issues.
  3. Planning Overlays: Some areas have special zoning restrictions, like flood zones or heritage overlays. If your property is in one of these areas, extra approvals may be required.
  4. Council Fees: The cost for building approvals, permits, and inspections can range from a few hundred to a couple thousand dollars. This depends on the size and complexity of your extension.

Budgeting and Costs for a Home Extension

Costs for a ground-floor extension can vary significantly, but here are some general guidelines:

  1. Typical Costs: Extensions generally cost between $2,000 to $4,000 per square metre. For a 50–80m² extension, this could range from $100k to $300k.
  2. Key Cost Factors:
    • Materials & Finishes: Standard brick veneer is cheaper than higher-end finishes like rendered exteriors.
    • Rooms & Wet Areas: Adding bedrooms or living areas is cheaper than adding a kitchen or bathroom. Wet areas require plumbing, which increases costs.
    • Complexity: A simple rectangular extension is cheaper than a more complex shape or design that requires structural changes.
    • Site Conditions: If the site requires excavation or retaining walls, costs will increase.
  3. Hidden Costs: Be prepared for unforeseen issues, like termite damage or rotten timber in the existing structure. Always add a contingency to your budget.

Finding the Right Builder (Sunshine Coast Providers)

Here’s who I’m looking at for my extension:

  1. Ward Builders: Ward Builders are highly recommended for house extensions. They’ve been operating for over 15 years and specialize in custom home alterations and extensions. They are known for their high-quality work and integrity. See more: https://wardbuilders.com.au
  2. Pinnacle Quality Constructions: Pinnacle Building is a well-regarded Sunshine Coast builder known for delivering high-quality extensions and renovations. They offer personalised service and handle everything from design to construction, ensuring a smooth process for clients. See more https://www.facebook.com/pinnaclequalityconstructions/
  3. Buildalife: Buildalife is known for its commitment to craftsmanship and customer satisfaction. They focus on delivering bespoke extensions and renovations that enhance the functionality and aesthetic appeal of your home. Their approach is collaborative, ensuring your vision comes to life seamlessly. See more: https://buildalife.com.au

After my research, I feel more confident about moving forward with the extension. The key is to plan thoroughly, choose the right builder, and stick to a realistic budget. I’ll be meeting with a few other builders to get quotes and find the best fit for my project.

Building an extension on the Sunshine Coast is a big job, but with the right planning and a trusted team, it’s definitely achievable. I’m excited to see how the project will unfold!

Sources:

  1. Ward Builders (https://wardbuilders.com.au/)
  2. Sunshine Coast Council Planning & Building Information

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