The Building Process
What are site costs when building a home?
Short answer
Site costs are the additional expenses to prepare your block for building - separate from the base house price. They cover the soil test, engineering, cut-and-fill, retaining walls, connections, and any regulatory overlays that apply to your block. Range: $15,000-$60,000+ depending on soil class, slope, retaining and how much fall is on the block.
The longer answer
Most Adelaide builders quote a "site cost allowance" upfront, then finalise after the soil test and contour survey. A P-class soil (problem soil) can multiply your slab cost by 2-3x compared to A-class (rock). Sloping blocks need retaining, split slabs or lifted floor systems.
Beyond soil, watch for: sewer connection depth, stormwater tanks or infiltration, driveway crossovers, and any overlays (bushfire, acoustic, flood, heritage) which each add compliance cost.
When comparing builder quotes, normalise the site cost allowance - two identical base prices with $20K vs $45K allowances is a $25K real-world difference.
Site costs are one of the most confusing and complex components in new home construction. In this episode we explain what site costs are, how they work, what they are made up of and ultimately help you understand why they vary between every block of land. We begin the episode with a short and sharp summary for those that want only the basics, and then we move into the more detailed explanation for those of you wanting to learn a bit more.
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