Cap Rates and Yield on Cost: The Two Yields That Decide Every Deal
One is the yield you build to. The other is the yield you sell at. The gap between them is your entire profit — and your only margin of safety. Master these two numbers and you can read any storage deal in five minutes.
Almost everything that goes wrong in a development deal can be traced to a developer who understood one of these two numbers but not the other. They knew their construction yield was good, but never checked what the market would pay for it. Or they fixated on cap rates and forgot that a low exit cap means nothing if your build cost too much. Cap rate and yield on cost are a matched pair. Neither means anything alone.
This guide is the two of them, properly defined, with current 2025–26 numbers — and the one relationship between them that decides whether you build or walk.
You build to one yield and you sell at another. The whole development business is the gap between those two yields. Everything else is detail.
Cap rate: the yield you exit at
The capitalization rate is the simplest idea in real estate dressed up in intimidating language. It's just annual net operating income divided by price:
That inverse relationship trips everyone up at first, so sit with it: when someone says "cap rates compressed," they mean prices went up — buyers accepted a lower yield to own the income. When cap rates "expand," prices fall. As a seller (which is what a merchant-builder is), you want to exit into low cap rates. As a buyer of dirt, you'd love high ones.
Where self-storage cap rates sit in 2025–26
After hitting a record-low average near 5.0% in late 2022, storage cap rates drifted up with interest rates and have settled, averaging around 5.8% across recent quarters. The spread by asset quality is wide:
| Asset class | Typical cap rate |
|---|---|
| Class A (new, prime metro, institutional) | 5.0–5.5% |
| Class B (good asset, secondary market) | 5.5–6.5% |
| Class C / value-add | 6.5–7.5% |
| Top-50 MSA average | 5.75–6.15% |
Ranges synthesized from 2025 self-storage market reports (Cushman & Wakefield, Skyview Advisors). Your exit cap should come from comparable sales in your submarket, not a national average.
The class spread is the whole reason development works: you build a brand-new Class A asset, but the cap rate you should underwrite is the one that asset trades at in your market — which is the number a feasibility study and local broker can pin down. Pick your exit cap from real comps, then build to beat it.
Yield on cost: the yield you build to
Yield on cost (also called development yield or untrended return on cost) is the same arithmetic pointed at your cost instead of a market price:
The denominator is everything here. Yield on cost is only honest if "total project cost" is genuinely all-in: land, hard costs, site work, soft costs, contingency, developer fee, and construction-period interest. Leave pieces out — as first-timers do when they use a "cost per square foot" that's really just the building shell — and your yield on cost looks great because the denominator is too small. A flattering yield on a fictional cost is how bad deals get green-lit.
The spread: where the two yields meet
Now the payoff. Put the two yields side by side and subtract:
Why both? Watch the value translate. Stabilized NOI of $440K, capped at your 6.0% exit, is worth $7.33M ($440K ÷ 0.06). You built it for $5.5M. The $1.83M difference — a third of your cost — exists only because your build yield (8%) beat your exit yield (6%). Collapse the spread to zero (build to 6%, exit at 6%) and the building is worth exactly what it cost: you took two years of development risk to create nothing.
How much spread do you need?
The long-standing rule is a spread of at least 150–200 basis points over the exit cap to justify development risk; with costs where they are, many developers now want 250–300. In today's tighter market, core-market yield-on-cost targets have compressed from roughly 8.5% toward 7.5% as rates softened — which means the spread is harder to find and worth defending. Below ~150 bps you're building for months to earn a trading-level return; you could have bought a finished asset on day one and skipped the risk.
| Spread (YoC − exit cap) | Read |
|---|---|
| < 100 bps | Walk. No margin for error; you're not paid for the risk. |
| 100–150 bps | Thin. Only with high conviction on cost and lease-up. |
| 150–250 bps | The fairway. A sound merchant-build spread. |
| 250+ bps | Strong. Real cushion against cost and rate surprises. |
The risk that quietly kills deals: cap rate expansion
Here's the trap that doesn't show up in a static pro forma. You underwrite a 200-bps spread assuming a 6.0% exit cap. But you don't sell today — you sell in three years, after construction and lease-up. If interest rates rise and your exit cap drifts to 6.5% while you build, watch what happens to the same $440K of NOI:
| Exit cap at sale | Stabilized value | Profit on $5.5M cost |
|---|---|---|
| 5.5% (compression) | $8.00M | $2.50M |
| 6.0% (underwritten) | $7.33M | $1.83M |
| 6.5% (expansion) | $6.77M | $1.27M |
| 7.0% (sharp expansion) | $6.29M | $0.79M |
A single half-point of cap-rate expansion erased $560K — nearly a third of your profit — without a single thing going wrong on the construction site. This is why the spread is a margin of safety and not just a profit figure: a fat spread is what lets you survive an exit cap that moves against you. It's also why you stress-test the exit cap, not just the rents and costs. The deal has to still work at a cap rate 50–100 bps worse than today's.
You can build the building perfectly and still lose money if cap rates move against you while you do it. The spread is the cushion that keeps that from being fatal.
See your spread instantly
Enter your land, build cost, rents, and exit cap — the free calculator returns your yield on cost and a go/walk read. The full model lets you flex the exit cap and watch profit, equity multiple, and IRR move with it.
Open the free calculator → Get the full modelThe five-minute read, every time
- Pin the exit cap from real comparable sales in your submarket — not a national average, not yesterday's number.
- Compute yield on cost on a genuinely all-in cost. If the denominator is soft, the yield is a lie.
- Subtract. Spread under ~150 bps over the exit cap and you walk before you spend a dollar on architecture.
- Stress the exit cap up 50–100 bps and confirm there's still a deal. If a small rate move wipes out the profit, the spread was never real.
Where to go from here
Cap rate and yield on cost are the verdict; the work that produces them is everything upstream — the all-in cost in the denominator, the unit-mix revenue and stabilized NOI in the numerator, and the development pro forma that strings it across time into an actual return. Learn to read the two yields first, though, because they tell you in five minutes whether the rest of the work is even worth doing.
Cap-rate data points drawn from 2025–26 self-storage market reports (Cushman & Wakefield, Skyview Advisors). Educational content only; not investment advice. Always underwrite to comps in your own submarket.