--- title: "15 Hidden Costs When Building a Home" description: "The costs your builder won't tell you about. From site costs to landscaping to blinds — here's what actually adds up beyond the build quote." source: HomeBuildBudget sourceUrl: https://homebuildbudget.com/guides/hidden-costs-building lastUpdated: 2026-06-16 citationUrl: https://homebuildbudget.com/guides/hidden-costs-building --- # 15 Hidden Costs When Building a Home The costs your builder won't tell you about. From site costs to landscaping to blinds — here's what actually adds up beyond the build quote. The costs your builder won't tell you about. From site costs to landscaping to blinds — here's what actually adds up beyond the build quote. Quick answer: Most Australian homeowners spend 15–25% more than their builder’s quote on costs not included in the contract. On a $600K build, that’s $90K–$150K in extras — covering site costs ($10K–$60K), landscaping ($10K–$80K), connections ($5K–$15K), blinds, fencing, driveways, and upgraded inclusions. The single biggest hidden cost is site works, which can blow out $30K+ above the builder’s allowance if you hit reactive soil or a sloping block. Budget 20–25% on top of the build quote for a realistic move-in figure. Data reflects Q1 2026 estimates from HIA and Master Builders Australia. Every builder’s quote has a line item called “site costs allowance,” usually somewhere between $15K and $25K. Sounds generous until you find out your block is sitting on reactive clay or has a 2-metre fall across the rear. Actual site costs regularly blow past the allowance by 2-3x (Master Builders Australia). Always get a soil test before signing a contract. The $1,000 you spend on that test could save you $30,000 in surprises. Site cost variation by city is substantial — see our city-specific guides for Melbourne, Sydney, Brisbane, and Perth. This gets everyone. Your builder’s “standard inclusions” mean laminate benchtops, basic tapware, and builder-grade tiles. You walk through the display home and fall in love with the stone benchtops, the matte black fixtures, the herringbone splashback. That’s all upgrade pricing. And once you start upgrading one thing, you end up upgrading everything because the standard stuff looks cheap next to it. Nobody thinks about this one. If you have a construction loan, you’re paying interest on every progressive drawdown during the 12–18 month build (RBA). That interest adds up to $10K–$25K, and somehow it never makes it into anyone’s spreadsheet until after the fact. Our construction loan vs home loan guide explains how progressive drawdowns work and what they’ll cost you. ### 1. Site Costs ($10,000 – $60,000+) ### 2. Landscaping ($10,000 – $80,000+) ### 3. Fencing ($5,000 – $20,000) ### 4. Driveway and Crossover ($3,000 – $15,000) ### 5. Blinds and Curtains ($3,000 – $15,000) ### 6. Air Conditioning ($5,000 – $20,000) ### 7. Connection Fees ($5,000 – $15,000) ### 8. Council Permits ($5,000 – $15,000) ### See your real build cost — including the extras ### 9. Architect/Designer Fees ($15,000 – $60,000) ### 10. Soil Test and Survey ($2,000 – $5,000) ### 11. Upgraded Inclusions ($10,000 – $50,000+) ### 12. Window Furnishings ($1,000 – $5,000) ### 13. Letterbox, Clothesline, TV Antenna ($500 – $2,000) ### 14. Temporary Accommodation ($15,000 – $40,000) ## Key Points - Get a fixed-price contract with a detailed inclusions list - Get a soil test before signing — don’t rely on the builder’s site cost “allowance” - Ask for the upgrade price list upfront — know what the display home extras cost - Budget separately for landscaping, fencing, blinds, and connections - Include a 10% contingency beyond the hidden costs - Most homeowners spend 15-25% more than builder’s quote on extras — that’s $90K-$150K on a $600K build - Site costs are the biggest hidden expense — can blow out $10K-$60K+ above allowance (always get independent soil test) - Landscaping typically costs $15K-$30K minimum for basic front/back yard (not included in build quote) - Budget $3K-$15K each for blinds, fencing, connections, permits — these add up fast - Upgraded inclusions (stone benchtops, better fixtures) add $10K-$50K+ over standard spec ## Frequently Asked Questions ### How Much Should You Budget for Hidden Costs? The real number: Add 20–25% to your builder’s quote for the true move-in-ready cost. On a $600K build, budget $720K–$750K total (HIA). Use our free building cost calculator to get a more accurate total project estimate including these extras. ### Can I reduce hidden costs by choosing a volume builder? You can, but there’s a trade-off. Volume builders have lower base prices because their standard inclusions are budget-grade. Walk through the display home, fall in love with it, then find out those finishes cost $15,000–$50,000 extra. A custom builder might quote higher upfront but actually include the things you want. The only number that matters is the total move-in cost. Compare that, not the contract price. --- *Source: [HomeBuildBudget](https://homebuildbudget.com/guides/hidden-costs-building)*