Guide · Cost
Short answer: it depends on your land and your structure — which is exactly why we assess those first.
“How much does it cost to add a second storey?” is the first question most homeowners ask. It’s also the one that can’t be answered honestly without looking at your block. Two homes on the same street can differ by hundreds of thousands of dollars once structure, access and council controls are factored in.
As a very rough guide for the North Shore and Eastern Suburbs, a quality second-storey addition typically lands somewhere in the range of $350,000 to $600,000+, depending on size and finish. Treat this as a starting frame of reference, not a quote — the real number is set by the factors below.
Before spending on design, it’s worth knowing whether a second storey is even the highest-value move for your block — or whether a ground extension, or dual occupancy, would return more. On the North Shore, land is often 60–75% of total property value, so the question isn’t just “what will it cost” but “what will it add.” That’s the difference between building and building strategically.
A genuine figure needs your structure assessed, your zoning and FSR confirmed, and a design scoped. Our free Block Assessment gives you the starting picture in 60 seconds; a Lot Strategy Brief turns it into a costed, decision-ready plan.
This is general information, not advice for your block. Zoning, FSR and structure differ site to site — the only way to know what your land can do is to check it. Start with our free Block Assessment, and for a definitive answer, a Lot Strategy Brief.
