Investor Tools

Granny Flat & Dual Occupancy ROI

Model the return on adding a granny flat or secondary dwelling. See the yield uplift, payback period, and income impact before you build.

Brisbane zoning check first

Secondary dwellings (granny flats) are permitted in Low-Medium Density Residential zones (LMR) and some Character zones in Brisbane. Some lots require a minimum size (typically 600m²). Check BCC CityPlan 2014 for your property before building. BCC CityPlan 2014.

Property Value ($)

Main Dwelling Rent ($/week)

Granny Flat Build Cost ($)

Expected GF Rent ($/week)

Finance Rate for Build (%)

Property Manager Fee (%)

Added Income / Year After management fees

Gross Yield — Before Main dwelling only

Gross Yield — After Combined on total value

Payback Period Net rent vs build cost

Annual Cash Flow Breakdown

Annual Finance Cost (interest only)

Net Cashflow After Finance

Est. Value Add (0.6x build cost)

Rule of thumb only — varies by suburb and build quality

This calculator is for indicative planning purposes. Build costs, rental income, and property value uplift vary significantly. DA approval, council contributions, and connection costs are not included. Always get fixed-price quotes from licensed builders and confirm BCC approval requirements before proceeding.

Want to know what this means for your property?

Daniel walks through your property, reviews recent sold results in your street, and gives you a clear number. Free, no obligation.

Book a Free Walk Through Call 0412 523 821

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