What are hidden costs in a home build

These are essential but often overlooked expenses that fall outside the standard building contract. They can add tens of thousands to your total spend, especially on complex or sloping sites.

Common hidden costs to watch for

Site works: Includes excavation, retaining walls, soil removal, rock breaking, and levelling. Costs vary widely depending on terrain and soil conditions.

Service connections: Charges to connect water, sewer, electricity, NBN, and stormwater. May involve trenching, permits, or infrastructure upgrades.

Council contributions: Also known as developer levies or infrastructure charges. These are fees paid to the council to support local services and can range from a few thousand to over $20,000 depending on location.

Reports and assessments: Required for planning approval and compliance:

• Geotechnical (soil) reports
• Bushfire Attack Level (BAL) assessments
• Flood studies
• Arborist or heritage reports

Temporary services: Includes site fencing, portable toilets, temporary power, and water supply during construction.

Insurance: You may need:

• Contract works insurance
• Workers compensation, if it applies to your arrangement
• Public liability cover
• Home warranty insurance, where your state requires it for work by a licensed contractor (it generally does not cover an owner builder’s own work)

Landscaping and fencing: Often excluded from builder contracts. Includes turf, plants, retaining walls, boundary fencing, driveways, and paths.

Interest and loan costs: If you’re financing the build, you’ll pay interest during construction, often on progressively drawn amounts. Also factor in loan setup fees and mortgage insurance if applicable.

Moving and setup: Final costs like removalists, cleaning, furniture, blinds, appliances, and internet setup can add up quickly.

Budgeting tip

• Hold a contingency as its own budget line. There is no single right figure, so set it with your quantity surveyor, lender or builder based on how complete your design and quotes are.
• Use platforms like My Build Hub to track these expenses in real time and avoid surprises.

Bottom line: Hidden costs are real, and they’re often the reason builds go over budget. Planning for them early and tracking them closely is the key to staying financially in control.