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Free, professional tools built for Australian owner-builders. Plan your build budget, compare builder and trade quotes, and keep your project on track — with calm, easy-to-use tools from the Owner Builder Institute. Everything runs right here in your browser, with nothing to download and no account to create.
Owner Builder Tools
Free Owner Builder Tools — Plan, Compare & Manage Your Build
Free, professional tools built for Australian owner-builders. No download, no account — everything runs in your browser, and every tool gives you a clean report you can share with builders, lenders and suppliers.
Ready to go further? Your owner builder course turns these tools into a complete, permit-ready plan.
Your Owner-Builder Toolkit
Every OBI tool speaks the same language and gives you a professional report you can share with builders, lenders and suppliers. Start with the two tools available now, with more on the way.
Why Owner Builders Choose OBI
Most calculators just crunch numbers. OBI tools guide you — pointing out what experienced owner-builders check at every stage — so you can make confident decisions and avoid costly surprises.
Ready to build with confidence?
Start with the Budget Planner: enter your estimated costs and OBI does the rest, including a smart contingency and a clear, shareable summary.