Site costs can make or break your building budget — and they’re one of the most commonly misunderstood aspects of the construction process. At Como Projects, we believe in complete transparency, which is why we’ve created this ultimate guide to site costs, helping you avoid hidden expenses and stay in control of your project from day one.
Whether you’re building a new home or undertaking a knockdown-rebuild, understanding site costs is key to setting realistic expectations and keeping your budget on track.
What Are Site Costs?
Site costs are the expenses involved in preparing your land for construction. Before any foundations are laid, your block must be assessed, levelled, cleared, and sometimes engineered — and that’s where site costs come in.
What Do Site Costs Include?
Site costs cover a range of pre-construction activities, including:
- Earthworks and site preparation
- Soil testing and engineering for foundations
- Local council permits and approvals
- Bushfire Attack Level (BAL) requirements
- Utility connections
- In knockdown-rebuilds, demolition (depending on the builder)
At Como Projects, we’re specialists in knockdown-rebuilds and include all critical elements in our process — including demolition — so you’re not left coordinating multiple contractors or facing unexpected bills.
How Are Site Costs Determined?
Site costs are unique to every block and depend primarily on:
- Soil type – Impacts how the foundation is engineered
- Topography – Affects the amount of excavation and site levelling required
Problematic soil and steep blocks typically result in higher costs because more work is needed to stabilise and prepare the site before construction can begin.
Can Site Costs Vary?
Yes — and they often do. Site costs can vary significantly even between neighbouring blocks. During construction, unexpected site conditions like rock, poor drainage, or unstable fill can emerge.
At Como Projects, we fix the majority of our site costs upfront in your contract. The only variables that may arise are:
- Rock removal
- Underground water management
- Traffic control (if required)
Everything else is clearly outlined, so you know where your money is going from the outset.
How Does Soil Type Affect Site Costs?
Your soil type plays a major role in determining the type of slab your home will need. Some soils — particularly clay-based, reactive soils — expand and contract with moisture, which can affect the structural integrity of your home if not properly addressed.
Lighter, sandy soils are more stable and typically incur lower costs. A soil test will determine your site classification in accordance with Australian Standards, guiding us to design the correct slab for your site — and protecting your home long-term.
How Does Topography Impact Site Costs?
Flat blocks are generally less expensive to build on because they require minimal excavation. Sloping blocks, however, need more intensive preparation, which can increase costs — especially if retaining walls or deep piering are required to stabilise the structure.
Choosing the right levelling method is crucial. For example, building on a filled block may require drilling into natural ground levels for stability, significantly increasing your site preparation budget.
Do Building Materials Influence Site Costs?
Yes — the structural materials you choose can influence your slab design and, in turn, your site costs. Lightweight materials such as timber often require fewer complex foundations than heavier materials like brick or steel.
Early material selection also helps avoid price hikes and delays later in the build. Locking in these decisions early is one of the best ways to protect your timeline and budget.
Are Any Site Costs Fixed?
Some initial site costs are typically fixed, including:
- Soil testing
- Feature surveys (to identify fall, connection points, easements, etc.)
- Council application fees and permits
At Como Projects, we provide full transparency and detail in our quoting process, helping you plan with confidence.
Avoid Surprises: Ask the Right Questions
We’ve also compiled a handy list of Questions to Ask Your Builder before you get started — ensuring you’re informed, empowered, and prepared to make the right choices for your home.
If you’re ready to break ground on your next big project — whether it’s a custom new build or a knockdown-rebuild — get in touch with Como Projects today and book a design consultation.
We’ll help you navigate site costs, avoid the pitfalls, and start your journey with clarity and confidence.
