Storage Expansion ROI Calculator
You can build more units — but does the NOI justify the capex? This runs the development test: yield on cost versus your cap rate. The spread between them is the value you create per dollar spent. Positive spread means building beats buying. Runs in your browser.
The build
The income
What the new units will earn once they've stabilized.
The benchmark
The cap rate you'd pay to buy this NOI instead of building it. The gap to your yield on cost is the development profit.
Stabilized NOI ÷ total cost to build
Total capex
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Added annual NOI
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Value created
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Profit over cost
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The development spread only pays out once the new units are full. Marketing that leases them up is what turns capex into value.
The math
How the development test works
What is yield on cost?
Stabilized added NOI divided by the total cost to build. It's the development version of a cap rate: what the new units earn per dollar you spend. If yield on cost beats the cap rate you'd pay to buy the same NOI, building creates value.
What's the development spread, and why does it matter?
It's yield on cost minus the market cap rate, in points. A positive spread means each dollar of capex converts into more than a dollar of value at exit, and that gap is your development profit. A spread near zero means you're building for the same price you could buy.
What should I use for the operating expense ratio?
Self-storage operating expense ratios commonly land in the 35–45% range of gross rent. New units bolted onto an existing facility often run leaner because they share staff and overhead, so a lower ratio can be defensible.
Does this account for lease-up time?
No. It models the stabilized year once the new units are full. New units take months to fill, so discount the early years accordingly. Use the lease-up calculator to estimate how long that takes.
Capex only pays once the units fill
A great development spread is worth nothing until the new units lease up. StorageAds runs the ads that fill them and proves which campaigns did it. Built by an operator, tested on our own facilities first.
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All toolsThis calculator is an estimating tool and does not constitute construction, financial, or investment advice. It models a stabilized year and ignores lease-up time, financing, and phasing. Confirm costs and rents with your builder and market before committing capital.