Small-bay has more ways to create income.
It also has more places for that income to leak out before it becomes NOI.
That is the tension hiding inside public CMBS loan data. In SpanVor's comparison, operating small-bay and flex properties produced approximately 70% more median NOI per building square foot than a high-confidence group of genuinely large industrial buildings.
That sounds like a victory lap. It is not.
Small-bay property revenue grew faster, but expenses grew faster still. The rent premium was real. So was the work required to keep it.
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First, stop defining the asset by total size
A small-bay park can be very large.
Century Business Center in Hawthorne, California, contains approximately 1.4 million square feet across 21 buildings. The average building is about 67,000 square feet, and the collateral is identified as flex. It is a large investment made up of smaller operating pieces.
Now compare it with a 169,700-square-foot FedEx distribution property where FedEx occupies approximately 78% of the space. The FedEx building is much smaller in total area, but it does not behave like a granular small-bay park.
Total collateral size tells you how large the pile is. It does not tell you how the property makes money.
For this analysis, the distinction comes from operating signals: flex designation, average building size, average tenant space, tenant concentration, property and building counts, drive-in doors, and clear height. Total size remains useful. It does not decide the category by itself.
That produced two primary groups:
- 708 operating small-bay/flex properties, with no total-size ceiling.
- 94 known large-building industrial properties, without a positive small-bay signal and with evidence that the average building is at least 200,000 square feet.
Another 1,647 smaller properties stayed unresolved because being under 200,000 square feet is not enough to establish an operating model.
The income-density premium is substantial
At securitization, the median operating small-bay property produced approximately $7.84 of NOI per building square foot. The median known large building produced about $4.58.
The latest annual figures preserve almost the same relationship: approximately $9.44 per square foot for small-bay versus $5.21 for the large buildings.
The comparison at a glance
- Properties: 708 operating small-bay/flex; 94 known large-building.
- Total area—median / average: 71,150 / 89,000 square feet for small-bay; 417,300 / 573,300 square feet for large buildings.
- Securitization NOI per square foot—median / average: $7.84 / $8.48 for small-bay; $4.58 / $5.22 for large buildings.
- Latest annual NOI per square foot—median / average: $9.44 / $10.64 for small-bay; $5.21 / $6.44 for large buildings.
- Latest NOI margin—median / average: 67.2% / 65.6% for small-bay; 71.6% / 73.7% for large buildings.
- Current DSCR—median / average: 2.11x / 2.38x for small-bay; 2.19x / 2.75x for large buildings.
Why the premium? Industrial space is priced in pieces. A local operator leasing 5,000 square feet generally pays more per foot than a national company taking 500,000. A park with ten buildings and forty suites can reprice smaller portions of its rent roll repeatedly. A single large building usually has fewer pricing events.
That granularity is what investors are buying.
But the property also has more turnovers, collections, repairs, common areas, leasing decisions, and tenant relationships. The work is not incidental to the return. The work creates the return.
The expense line caught the revenue line
Operating small-bay property revenue grew faster than revenue at known large buildings. From securitization to the latest comparable observation, median annual property-revenue growth was approximately 3.5% for small-bay and 2.2% for large buildings.
Then expenses arrived.
Annualized growth—median / average
- Property revenue: 3.48% / 3.83% for small-bay; 2.21% / 2.75% for large buildings.
- Operating expenses: 7.18% / 8.17% for small-bay; 4.53% / 6.59% for large buildings.
- NOI: 2.63% / 2.76% for small-bay; 3.04% / 3.54% for large buildings.
That is the report in three rows.
Small-bay revenue grew faster. Small-bay expenses grew faster still. By the time the extra revenue reached the NOI line, the large buildings had caught up and moved ahead.
The annual reporting panel tells the same story. Small-bay recorded approximately 4.2% median annual revenue growth, versus about 2.5% for large buildings. Expenses grew about 5.6% versus 3.9%, leaving median NOI growth of roughly 2.7% and 2.0%, respectively.
The exact values change with the reporting window. The operating lesson does not:
The rent-and-revenue opportunity is real. Capturing it requires controlling expenses.
Value-add can explain thin coverage—but not every miss
Small-bay buyers often accept thinner day-one coverage because the asset offers frequent renewals, lease-up potential, and a quicker path to market rents. That is a reasonable business plan.
It is not a blanket explanation for every loan below 1.25x DSCR.
Among operating small-bay properties with usable current coverage, 38 were below 1.25x and 220 were at or above it. The weaker group entered with less cushion and slightly more leverage. It then lost occupancy and revenue while expenses continued rising.
The median weak loan versus the rest
- DSCR at securitization: 1.67x below the 1.25x line; 1.92x at or above it.
- Current DSCR: 0.97x below the line; 2.32x at or above it.
- Current occupancy: 94% below the line; 100% at or above it.
- Property-revenue growth: -0.86% below the line; 4.74% at or above it.
- Expense growth: 7.43% below the line; 7.18% at or above it.
- NOI growth: -8.63% below the line; 4.16% at or above it.
Some of those properties may still contain unfinished value-add stories. As a group, however, the result looks like operating deterioration—not simply upside waiting patiently to arrive.
A mark-to-market plan is not a result until the revenue appears and survives the expense line.
Single-tenant and NNN deserve their own category
Small does not automatically mean small-bay. Single-tenant does not automatically mean NNN. And NNN does not describe every lease inside a multi-tenant park.
In the detailed CMBS subset, at least 530 properties below 200,000 square feet were confirmed single-tenant or at least 90% concentrated in one tenant. Their lease structures are not complete enough to call every one NNN, but they clearly should not define a granular operating-small-bay comparison.
Several top-loan descriptions show why:
- Precise Space in Rhome, Texas contains commercial-van, utility, pickleball, baseball, CrossFit, and custom-automotive businesses—a recognizably diverse operating property.
- 540 Tech Center in Raleigh is a 111,000-square-foot flex property with three tenants and visible rent mark-to-market potential.
- 2000 Corporate Center in Thousand Oaks is about 105,000 square feet, but two tenants occupy roughly half apiece.
- Fresh Edge Portfolio in Indianapolis reports full occupancy and no operating expenses in the extracted underwriting summary, demanding a net-lease review rather than automatic small-bay treatment.
The useful framework has four buckets: operating small-bay/flex, single-tenant or net-lease industrial, large-format industrial, and unresolved.
The markets are not keeping the premium equally well
The state cuts are directional, not a league table, but several patterns are worth following.
California and Texas converted stronger revenue growth into meaningful NOI growth. Nevada, driven largely by Las Vegas, was the most striking result—but only twelve properties qualified, so it is a lead for deeper work rather than a sweeping conclusion.
Florida and Illinois faced the opposite problem. Revenue generally rose, but expenses rose much faster. In Florida, median revenue grew approximately 3.3% while expenses grew about 6.7%. In Illinois, expense growth approached 9%.
Those markets did not lack revenue opportunity. They struggled to keep it.
What I would underwrite harder
The CMBS tape does not argue against small-bay. It argues against underwriting small-bay as passive industrial.
If I were reviewing an acquisition, I would spend less time debating whether market rent can rise by another dollar and more time asking what it costs to collect that dollar:
- Which expenses are actually recoverable?
- How quickly do reimbursements reset?
- Are pro-rata shares accurate?
- How much of an insurance or tax increase reaches the tenants?
- What does a normal suite turnover cost after paint, HVAC, doors, office buildout, and leasing commissions?
- Is the property staffed for forty small relationships—or underwritten as though it has four?
- How many leases roll before the mark-to-market can be captured?
- Does the debt leave room for the uneven path between today's occupancy and the business plan?
Large-format industrial asks different questions. Its operating statement is usually simpler and its margin is better, but tenant concentration dominates the risk. One renewal decision can matter more than an entire year of small-bay expense management.
Same sector label. Different machines.
The bottom line
Operating small-bay produced approximately 70% more NOI per building square foot in the CMBS comparison. Property revenue grew faster. The opportunity was real.
So was the cost.
Small-bay is not miniature big-box industrial. It should not be defined by an arbitrary size ceiling, valued like a passive warehouse, or operated as though forty tenants behave like one.
It is a dense income machine.
The revenue premium is the opportunity. The expense line is the job.
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See the operating model behind the address. SpanVor brings property, ownership, building, and market intelligence together across the national industrial universe.
This analysis uses public SEC commercial-mortgage filings assembled in SpanVor's CMBS warehouse. It evaluates operating and credit performance—not investor IRR or total return. It is research and commentary, not investment advice.