Soil and slope: the costs you cannot see from the street

Two blocks in the same Melbourne estate can cost very different amounts to build on, and the reason is usually underground. Much of Melbourne's growth belt sits on reactive clay - parts of Wyndham, Melton and the western suburbs are well known for it - which needs a stronger, more expensive slab and footing system. A soil test gives you the site classification (from stable through to highly reactive), and that classification feeds straight into your site-works cost.

Slope and fill matter just as much. A block that falls across its width needs cut-and-fill, retaining and sometimes a split-level or drop-edge design, all of which add cost. The flattest, most stable block in an estate is often worth paying a premium for once you account for what an awkward block adds in site works. Always get a soil test and a site assessment before you commit, not after.

• Get a soil test for the site classification (reactive clay is common)
• Assess slope and fall - cut, fill and retaining add real cost
• A flatter, more stable block often beats a cheaper awkward one

Planning: overlays, zoning and the VicPlan check

Before you fall in love with a block, run it through VicPlan - the Victorian Government's planning property report. It tells you the zoning and any overlays that apply: bushfire (BAL), flooding, significant landscape, heritage, vegetation protection and development contributions. An overlay does not necessarily rule a block out, but it can add requirements and cost - a Bushfire Attack Level assessment on a fringe block, for example, can change the construction standard and the price.

In established suburbs (relevant if you are buying to knock down and rebuild) neighbourhood-character and heritage controls can shape what you are allowed to build. In growth-corridor estates, the developer's own design guidelines often dictate facade, fencing and landscaping standards and timeframes. Read both the planning controls and the estate guidelines before you sign.

• Run the block through VicPlan for zoning and overlays
• Check for BAL (bushfire), flood, heritage and vegetation overlays
• Read the developer's estate design guidelines - they are binding

Orientation, size and the home you can actually fit

Orientation is free performance. A block where living areas can face north gives you a warmer, cheaper-to-run home and an easier path to the 7-star NatHERS energy rating Victorian new homes must meet. A poorly oriented block can be worked around, but it costs you in glazing, shading and heating. Think about which way the living spaces will face before you choose.

Block size and shape decide which designs fit. Newer corridor estates increasingly sell compact 250-350m² lots, which suit double-storey or narrow-lot designs rather than a sprawling single-storey. Check the lot dimensions, easements and the build envelope against the home you actually want - a builder can tell you quickly whether your preferred design fits the block or needs to change.

GAIC, registration and the buying timeline

Two Melbourne-specific traps catch growth-corridor buyers. The first is the Growth Areas Infrastructure Contribution (GAIC) - a levy that can apply when certain growth-area land is subdivided or built on; check whether it affects your lot and who is liable. The second is "on registration" selling: many corridor lots are sold before the title legally exists. You pay a deposit, but settlement and your build start wait until the developer registers the plan of subdivision, which can take months and occasionally slips. Always confirm the expected registration date in writing and build it into your finance and rent timeline.

Before you commit, stack up the all-in cost: land price, stamp duty (check first-home concessions with the SRO), GAIC if applicable, site costs from the soil test, connections and authority fees. BuildPilot is live in Victoria - tell us the block you are considering and we will match you with builders who know that corridor and can price the build on your actual site.

• Check if GAIC applies to the lot and who pays it
• For "on registration" lots, confirm the registration date in writing
• Add stamp duty, site costs, GAIC and connections to the all-in budget
• Confirm first-home stamp-duty concessions with the SRO Victoria