425-Unit Self-Storage Facility in Hillsborough County, Florida: An SBA 504 Model Study

Model study: an illustrative feasibility analysis built on public data for Hillsborough County, Florida; not a client engagement.

Project summary

The credit question

A self-storage facility is an unusual 504 file because the collateral and the business are the same thing: there is no operating company with a record of earnings that the building supports. A lender is testing whether enough nearby households will rent space at the assumed rates, whether the facility reaches those rates and that occupancy before the sponsor's cash runs out, and whether the cost of owning a building on Florida's Gulf Coast (property tax, windstorm insurance, deductibles) leaves enough margin for two layers of fixed-rate debt.

The question is narrower than "is this a good market." At the Year 5 net operating income the facility can plausibly produce, does the combined first-lien and debenture payment leave a margin that survives lower rents, a slower lease-up or a hurricane deductible? A second question follows from the program: does SBA treat a self-storage facility as an operating business occupying its own property, or as a business that owns real estate and leases it, which SBA makes ineligible [1]?

The short answer from public data: the county's demand base is large and growing, the model's rents are assumptions that a site-level rate survey must confirm, and at the minimum 504 contribution the project does not cover its debt. The rest of this page shows why, and what structure would.

Location and county economy

Population and growth

Hillsborough County had an estimated 1,574,115 residents on July 1, 2025, according to the Census Bureau, 107,869 more than the July 2020 estimate of 1,466,246, an increase of 7.4% [3]. Growth has slowed sharply: the Census series shows only 2,917 additional residents between July 2024 and July 2025 (0.2%), after gains of 40,332 in 2022 and 31,217 in 2023 [3]. Florida's Demographic Estimating Conference and the University of Florida's Bureau of Economic and Business Research (BEBR) put the April 1, 2025 population at 1,575,637 and project 1,684,960 in 2030 and 1,767,366 in 2035 in their medium series [4].

Storage demand comes from household formation and moves, not the population stock. The model uses the BEBR medium path (1.35% a year to 2030, computed from the projection) as the trade-area growth rate because it is the official state planning basis, but the 2025 Census reading signals slower in-migration, and a slower lease-up is tested for that reason.

Households, tenure and income

The American Community Survey counts 606,538 households in the county, averaging 2.55 persons [5]. Of those, 234,064 rent, a renter share of 38.6% [5]. Renters, particularly in apartment buildings, have less closet, garage and attic space than owners of detached homes, and they move more often. Almost a quarter of housing units (158,910 of 656,536, or 24.2%) are in buildings of five or more units, another 41,358 are mobile homes, and 14.2% of residents aged one and over moved in the prior year [5]. That describes a population that churns through housing and periodically needs somewhere to put belongings, which is the core self-storage customer.

Income supports the rate assumptions. Median household income was $85,183 in the ACS 2024 1-year estimate [5] and $84,691 in the 2024 SAIPE estimate [6], up 29.8% from $65,272 in 2020 [7]. At the model's assumed $135 a month, a 10x10 climate-controlled unit costs about 1.9% of median monthly household income. The median owner-occupied home is valued at $420,000 and the poverty rate is 11.5% [5].

If household size holds near 2.55, the BEBR projection of 109,323 additional residents by 2030 implies roughly 43,000 additional households. That is derived from published inputs, not a published household projection, and it supports the trade-area demand growth below.

Housing activity and commuting

Private housing units authorized fell from 17,443 in 2022 to 9,053 in 2024 and 8,696 in 2025 [8], and mean travel time to work is 29.9 minutes [5].

Two points bear on a storage credit. MacDill Air Force Base sits in the county, and military households relocate on orders, creating demand that is not tied to the local housing cycle. And the 50% fall in permits since 2022 [8] matters because new housing deliveries drive move-related storage demand with a lag, so 2027 to 2029 will see fewer new-home arrivals than 2023 to 2025 did. The near 30-minute commute [5] argues for a tight trade area: the demand that matters is the population within about three miles of the site, not the county total.

Market analysis

Demand drivers

In order of weight, demand comes from renter households and apartment density [5], residential mobility [5], population growth of about 1.35% a year to 2030 [4], military relocation tied to MacDill, and small business users. Hurricane recovery can add temporary demand, but a lender cannot count on a disaster for revenue, so none is modelled.

Rents and occupancy benchmarks

No public source reports rents and occupancy for a trade area this small, so the model's street rates, in-place premium, concessions and stabilized occupancy are assumptions, listed in the register below. A new facility starts with only new leases at street rates and reaches mature pricing only as tenants age into increases; that gap explains most of the lease-up shortfall in the pro forma. A site-level rate survey of competing facilities is a condition of the model's determination.

The model holds street rates flat from September 2026 to the 2028 opening and grows them 3.0% a year from Year 2, an assumption tested at 10% and 20% below.

Existing supply and pipeline

No official source counts storage facilities around a specific site, so trade-area supply is an assumption a lender must replace with a survey of facilities within 3 and 5 miles.

Demand method: supply per capita and implied occupancy

The method compares trade-area supply with a supportable level of supply, defined as trade-area population times an assumed benchmark of 7.1 sq ft per capita. It then converts supply into implied market occupancy using occupied demand per capita of 6.48 sq ft (7.1 sq ft times an assumed 91.2% market occupancy). The trade-area inputs are assumptions: a 3-mile radius holding 75,000 residents in 2026, existing supply of 470,000 NRSF (6.27 sq ft per capita, an under-supplied submarket, which is the reason a sponsor would choose the site), and a 40,000 NRSF competitor delivering in 2027. Population grows at the BEBR county medium rate of 1.35% a year [4].

All figures in this table are modelled. Supply, population and occupancy for the trade area, the 7.1 sq ft benchmark and the 91.2% occupancy factor are assumptions; the growth rate follows the BEBR county medium path [4].

Before the competitor and the project open, the trade area is about 62,500 sq ft short of the benchmark. The competitor takes 40,000 sq ft of that gap and the project adds 52,875, so in 2028 the trade area is 15,893 sq ft over the benchmark and implied market occupancy is 88.6%. Population growth absorbs the excess by 2030, and implied occupancy reaches 93.5% by 2032. The project's ramp (88% in 2031, 90% in 2032) tracks just below that line, as it should for an independent entrant facing established operators.

The project is therefore about two years ahead of its trade area's demand. Every year growth falls short of the BEBR path, the excess persists. The existing-supply count is the most important diligence item: if a site survey finds more than about 7.0 sq ft per capita before the project, this occupancy ramp is too fast.

Forecast

The pro forma uses the ramp in the lease-up table below. Concessions fall to 2% of rent from Year 4, and stabilized occupancy is 90%; both are assumptions.

Site and technical

Site requirements

The modelled site is 2.6 acres on an arterial road in unincorporated Hillsborough County, with road visibility, access usable by moving trucks and room for a monument sign. Storage customers choose largely by proximity and search ranking, so a site behind a retail strip or at the end of an industrial road will lease more slowly than the curve used here.

The plan assumes one single-storey climate-controlled building of 26,719 gross sq ft (80% efficiency, including the office) and drive-up buildings of 32,812 gross sq ft (96% efficiency), with a perimeter fence, gated keypad entry and cameras. A single storey avoids elevators and fire-separated stairs, which cuts cost and wind exposure but uses more land.

Zoning, permits and environmental

Self-storage is commonly classed as a commercial or light-industrial use, but this study did not verify which Hillsborough County zoning districts permit it or what approvals apply. A lender should require a zoning verification letter, an approved site plan and any stormwater permit before the interim loan closes. SBA requires an environmental investigation of all commercial property offered as security; if the parcel's current or prior uses match a listed environmentally sensitive industry, it must begin with a Phase I [1].

Hillsborough County's updated coastal Flood Insurance Rate Maps took effect October 7, 2021, replacing maps based on data more than 30 years old; owners with federally backed mortgages in zones beginning with A or V are required by their lenders to carry flood insurance [9]. SBA requires flood insurance on any collateral building partly in a special flood hazard area, and on personal property collateral in it [1]. The model assumes Zone X. An A or V zone would add premiums and real exposure to tenant contents claims.

Construction approach

The assumed system is pre-engineered metal buildings with insulated panels for the climate-controlled structure and roll-up doors on the drive-up buildings, designed to the Florida Building Code's wind provisions. Roll-up doors fail before walls do, and a failed door exposes stored goods, so the budget carries wind-rated doors and a 6% hard-cost contingency.

Schedule

The modelled schedule, all assumptions, runs from site control: due diligence, survey, geotechnical and environmental work in months 0 to 3; site plan, zoning verification and permits in months 3 to 9, overlapping the 504 application, CDC and SBA approval and interim loan closing in months 4 to 9; 12 months of construction from month 9 to month 21; opening at month 21, which starts operating Year 1 in 2028; the debenture sale and interim take-out around months 23 to 25; and lease-up to 88% by the end of Year 4, about month 69. The gap between approval and the debenture sale, roughly 14 to 16 months, is the window in which rate risk sits with the borrower.

Hurricane and insurance exposure

Windstorm is the cost line that most separates a Florida storage file from one elsewhere. Two 2024 storms show the exposure for this county. Helene, which made landfall in Florida's Big Bend region, still drove water levels to 7.20 feet above mean higher high water at East Bay and 6.83 feet at Old Port Tampa, and the Tampa Bay weather office recorded 14 direct deaths [10]. Milton made landfall on the west-central peninsula as a category 3 hurricane about two weeks later, produced 12 tornadoes in the Tampa Bay office's area, a gust of 83 knots at Tampa International Airport, and 16.51 inches of rain at a station 5.1 miles south of Tampa [11]. For a storage facility the wind and rain risks bear on roofs and roll-up doors, the surge risk on site selection, and both on tenant contents claims and on the business interruption that follows a loss.

Insurance is priced accordingly. The model's insurance line, $54,000 in Year 1 and $65,637 by Year 5, is 7.7% of stabilized income, and a 5% named-storm deductible on the $5.28 million of hard cost and contingency would cost $263,843 after a storm. Citizens Property Insurance cut its average commercial nonresidential rates for policies effective on or after July 1, 2026 [12], but that can reverse after a loss year. A lender should treat the premium as a quote to be bound, not an estimate.

Development budget and sources and uses

Assumptions register

Every modelled figure not taken from a cited source is listed here.

Development budget

Hard costs before contingency total $4,978,160. Restructured, the interim loan covers 60% of cost instead of 85%, so construction interest falls to $242,349 and the bank fee to $34,745, for a total of $6,949,070. Development cost excluding financing, the basis for the unlevered return, is $6,671,976 in both cases. The permits-and-fees line is an assumption to be replaced with the county's impact and mobility fee schedule.

Sources and uses

Uses equal the development budget above. The operating deficit reserve is not an eligible 504 project cost; it is cash the sponsor must hold, pledged or escrowed, to carry the facility through lease-up.

Revenue build and operating expenses

Unit mix and gross potential rent

Climate-controlled units are 54% of the unit count but 40% of rentable area. In the model, climate control earns $18 a month more on a 10x10, a 15% premium; drive-up space is cheaper to build and suits contractors and vehicle-adjacent storage. Gross potential rent at the assumed street rates is $731,100, or $13.83 per NRSF.

Lease-up ramp

All figures are modelled. Year 1 rent per occupied sq ft of $12.44 reflects an opening year in which every tenant is new and many receive move-in discounts. Year 2 revenue per available foot is 56% of the Year 5 level, which is why debt is not covered from operations until Year 4 even restructured.

Operating expenses

Percentages are of effective gross income in that year.

The stabilized expense ratio of 45.6% is high for self-storage, and that is the analysis, not a flaw in it. A single independent facility cannot spread a manager over thousands of units, pays a management fee, carries a lender-required reserve, and buys windstorm cover in the Florida market rather than through a national program. Insurance is 7.7% of income at stabilization. Property tax is a large line because the 2025 unincorporated millage of 18.2515 mills applies to every owner [14]. The model grows insurance 5% and taxable value 3% a year, and stresses both.

Taxable value steps from $4.2 million in Year 1 to $5.52 million in Year 5, against a $7.06 million cost, on the assumption that the appraiser values a leasing-up facility below cost. If the appraiser assesses at cost from the first January 1, Year 1 tax rises by about $52,000; the insurance-and-tax stress case covers this.

10-year pro forma

All figures in dollars. Year 1 debt service is lower because the bank loan is interest-only for 12 months. Restructured debt service and cash flow appear in the DSCR table. Year 11 NOI, used for the exit, is $542,700.

Year 5 NOI of $462,531 is a 6.56% yield on the as-submitted project cost, and that yield decides the file. As submitted, debt service of $521,428 exceeds NOI through Year 9 and the sponsor funds $1,429,513 of shortfalls. Restructured, debt service of $362,605 is covered from Year 4.

Debt structure under the program

SOP 50 10 8.1 requires a borrower contribution of at least 10%, 15% for a new business or a limited or special purpose property, and 20% when both apply; at 15% the debenture finances no more than 35% and the third-party lender at least 50% [1]. The SOP defines a new business as one in operation for two years or less when the loan is approved [1], and 13 CFR 120.910 sets the same contribution tiers [2]. A newly formed operating company is a new business, so the as-submitted case uses 15%.

Self-storage is not on the 504 list of examples of limited or special purpose property in SOP 50 10 8.1, which includes cold storage facilities more than 50% equipped for refrigeration, car washes, gas stations, hotels and marinas; the list is not all-inclusive, and the CDC must address the question in its credit memorandum [1]. The SOP's change-of-ownership guidance does give "storage units and hotels where the real estate fully secures the loan" as examples of special purpose property [1], so a special purpose finding is a real possibility. The model treats the facility as general purpose. A special purpose finding would raise the new-business minimum to 20% [1], which does not change the conclusion, because the file needs far more than 20% to cover its debt.

The SOP states that an additional borrower contribution reduces SBA's portion of the financing [1]. That is the restructured case: the bank stays at 50%, the borrower rises to 40% and the debenture falls to 10%. The third-party loan must be at least as much as the 504 loan and, for a new business, at least 50% of project cost [2]; both cases comply.

Rates and terms. Debenture rates are set at sale, and the 10-year Treasury rate is the usual benchmark for 20- and 25-year debentures [1]; it yielded 4.88% on November 9, 2026, and prime stood at 7.00% [13]. The 7.00% debenture and 7.25% bank rates are assumptions anchored to those. The bank loan must run at least 10 years beside a 25-year debenture [1]; on a 25-year amortization it leaves a Year 10 balloon of $2,892,949 as submitted and $2,849,165 restructured, which the SOP requires the loan report to justify [1].

Fees. The gross debenture finances a CDC processing fee of up to 1.5% of the net debenture, a closing fee of which up to $10,000 may be financed, and a 0.4% fee charged when a 20- or 25-year debenture is sold [1]. SBA charges a 0.5% guaranty fee on the debenture and an annual fee capped by regulation at 0.9375% [2], with the annual rate set each fiscal year [1]; the CDC servicing fee is at least 0.625% a year [2]. A one-time 0.50% participation fee on the senior lien [1] is not in the budget and would add $17,640 if passed to the borrower. The model's $70,450 of financed costs is $37,043 processing, $12,348 guaranty fee, $10,160 debenture sale fee, $10,000 closing fee and $899 rounding; ongoing fees sit inside the 7.00% rate.

Debenture size and equity basis. The gross debenture is capped at $5,000,000 per business and affiliates outside energy and manufacturer projects [1]; both cases are well below it. The contribution may be cash, land in the project, or borrowed funds subordinate to the third-party loan and the debenture and, without SBA's written approval, not repaid faster than the 504 loan [1]. Restructured, the borrower's $2,779,628 plus the $680,286 lease-up reserve means $3,459,914 of sponsor cash or land.

DSCR and break-even

All figures are modelled. The Year 1 ratio is more negative under the restructured case only because the same negative NOI is divided by a smaller debt service; in both cases Year 1 NOI is below zero. SOP 50 10 8.1 sets a 504 debt service coverage minimum of 1.15, measured as EBITDA over combined post-transaction debt service, and for a projection-based project the CDC must analyze at least two years of projections [1]. The restructured case clears 1.15 in Year 5 on the model's NOI basis.

Break-even. Holding Year 5 rates and expenses, NOI equals debt service at 96.7% occupancy as submitted, far above the model's 90% stabilized occupancy and beyond reach for an independent facility. Restructured, break-even falls to 78.6%, an 11.4-point cushion below the forecast. Operating break-even (NOI of zero) is 38.1% occupancy, reached during Year 2.

With the bank held at 50%, a borrower contribution of 36.4% produces a Year 5 DSCR of 1.20x, 38.8% produces 1.25x and 41.1% produces 1.30x.

On the collateral side, Year 5 NOI is a 7.6% debt yield on original debt as submitted and 11.0% restructured; valuing Year 6 NOI at 6.50%, loan-to-value at the end of Year 5 is 76.8% and 53.4%.

Returns

The unlevered IRR of 6.8% is below the 7.00% to 7.25% cost of debt. When an asset yields less than its debt costs, each added dollar of debt lowers the equity return, which is why the levered IRR sits below the unlevered IRR and rises as debt falls. Value creation is thin: $7.06 million of cost produces an $8.35 million exit value, about 18% over ten years. A lender is not lending against the sponsor's return, but a sponsor projecting 5.3% on $3.46 million has limited reason to defend the asset in a downturn, and the credit memorandum should say so.

Sensitivity and stress tests

Year 5 DSCR, restructured case: rate change against stabilized occupancy

All figures are modelled. Rate risk sits mostly between approval and the debenture sale, about 14 to 16 months in this schedule. At 90% occupancy, a 50 basis point rise takes the restructured DSCR from 1.28x to 1.22x, below a 1.25x policy line. Occupancy matters more: a drop from 90% to 84% costs 0.15x, against 0.11x for a 100 basis point rise.

Year 5 DSCR: street rates against stabilized occupancy, both structures

The as-submitted structure does not reach 1.25x anywhere in this modelled grid, even with rents 20% higher at 92% occupancy (1.23x). The problem is not one soft assumption but the ratio of debt to what a facility of this size can earn here.

Downside scenarios

Scenario D treats a 5% deductible on hard cost plus contingency as an uninsured cost in the storm year, with business income cover after the waiting period. The upside case puts Year 5 rent per available sq ft at $17.99.

What the scenarios say:

• Rents and cost inflation are equal threats. A permanent 10% rent cut (A) and a 75% insurance increase with 25% higher tax (C) both take the restructured DSCR to about 1.06x to 1.07x. The insurance market has eased for this class: Citizens Property Insurance cut its overall average statewide rates for commercial nonresidential multiperil policies by 1.8% and for wind-only policies by 5.0%, effective on or after July 1, 2026 [12]. That can reverse after a loss year.
• A slower lease-up is a liquidity problem. Scenario B still reaches 1.17x in Year 5 but nearly doubles funded shortfalls to $1,243,212. The reserve fails before the coverage ratio does.
• A storm is a one-year event with a large deductible. Scenario D drops one year's DSCR to 0.55x. The protection is a deductible reserve, not a higher coverage covenant.
• Combined downside breaks the credit. Scenario F gives 0.76x at stabilization and $1.9 million of sponsor funding, so the file needs a guarantor with real liquidity.

Program compliance

How SBA treats self-storage: what the current rules say

This study searched the full text of SOP 50 10 8.1 for self-storage, mini-storage and mini-warehouse. None appears, and the SOP's eligibility rules and its 504 list of limited or special purpose properties do not name self-storage [1]. The one mention of storage units is in the SOP's change-of-ownership guidance, which lists "storage units and hotels where the real estate fully secures the loan" as examples of special purpose property [1]. Eligibility turns on general rules that pull in different directions.

The passive-business rule bars businesses "primarily engaged in owning or purchasing real estate and leasing it for any purpose" [1], and the regulation bars landlords that do not actively use the financed assets [2]. Read literally, renting units is renting space. But a storage operator actively uses the whole property: it staffs the office, sells supplies, runs access control, sets rates, collects, and enforces liens under Florida's storage statute, which requires a written demand allowing at least 14 days, a newspaper advertisement once a week for two consecutive weeks, and a sale at least 15 days after first publication, which may be held on a public auction website [18]. Those are the activities of an operating service business.

Two newer SOP tests must be cleared. Business models that rent space to independent businesses serving the public, such as salon suites, are ineligible unless revenue is membership dues rather than rent, among other conditions [1]; household storage falls outside this, but contractor bays or flex workspace would invite it. And businesses structured as a stand-alone asset operated on a passive basis are ineligible [1]; a kiosk-run facility under a manager with sole discretion is the most exposed version.

Under 13 CFR 120.131 a new building's borrower must permanently occupy at least 60% of rentable property and may permanently lease no more than 20% [2]. If unit rentals counted as third-party leases, no storage facility could qualify; a storage 504 loan works only if customers are treated as users of the operator's service, so that the operating company occupies 100%. This study found no current SBA document stating that position. A lender should obtain the CDC's written eligibility analysis, and SBA's concurrence on a non-delegated file, before the borrower spends on entitlements.

The job test is the second problem. At one job per $95,000 guaranteed by SBA [1], the $2,540,000 debenture would need about 27 jobs and the $722,000 debenture about 8, against about 1.5 full-time equivalents. The project must qualify under a 13 CFR 120.862 goal, such as stimulating other business development or expanding businesses owned by women, veterans or minority owners, with the CDC's overall portfolio, including this loan, meeting its job average [2]. A CDC with a thin portfolio average may decline the file on that alone.

Risks and mitigants

Model determination

As submitted, the modelled project is not financeable. At the 15% minimum contribution the structure places $6.07 million of debt on a facility producing $462,531 of stabilized NOI. Debt service of $521,428 exceeds NOI through Year 9, the Year 5 DSCR is 0.89x, and break-even occupancy is 96.7%. It stays below 1.25x even with rents 20% higher at 92% occupancy.

The cause is yield. A 6.6% stabilized yield on cost against 7.00% to 7.25% debt leaves no room for 85% financing.

Restructured, the project is conditionally financeable. With the bank at 50%, the debenture at 10% and the borrower at 40%, the Year 5 DSCR is 1.28x, Year 4 is 1.14x and break-even occupancy is 78.6%. The 504 piece becomes small; its value is a 25-year fixed rate on the second lien and bank exposure held to 50% of cost.

The conditions a lender would likely set:

1. Borrower contribution of at least 38.8% (the 1.25x point), modelled at 40%, verified as cash or project land before the interim loan funds.
2. A lease-up reserve of at least $680,000, released after two consecutive quarters at 1.20x trailing coverage, plus a guarantor liquidity covenant sized to the $1.24 million slow-lease-up shortfall.
3. A written SBA eligibility position that the facility is an operating business occupying 100% of its rentable property, with owner oversight of management, and a stated special purpose finding.
4. A confirmed 13 CFR 120.862 goal and evidence that the CDC's portfolio can absorb a project that creates about two jobs.
5. A site-level supply and rate survey within 3 and 5 miles, with the file re-sized if existing supply exceeds about 7.0 sq ft per capita or street rates come in below the model.
6. Insurance bound before closing: wind, flood if any part of the site is in an A or V zone, business income, and a named-storm deductible no larger than the funded reserve.
7. A guaranteed maximum price contract within the $4.98 million hard-cost budget plus 6% contingency, specifying wind-rated doors.
8. Tax and insurance escrow and an annual DSCR covenant of 1.20x tested from Year 5.

Under those conditions the lender holds collateral at 53% loan-to-value by Year 5, backed by a large renter population, and the main downside is sponsor liquidity rather than collateral loss. Without them, this is a construction loan to a facility that cannot pay its debt.