Case Study · Arizona · Self-Storage · SBA 504
Self-Storage Feasibility Study, Arizona — An SBA 504 Worked Case
This is how our independent feasibility study company and consultant team analyzed a new-build, climate-controlled self-storage facility underwritten to an SBA 504 credit, from square-feet-per-capita trade-area demand through the debt-service coverage a lender must document across a multi-year lease-up. It is a representative, anonymized worked example of the methodology — not a specific client deal — set in a fast-growing suburban submarket of metro Phoenix, Arizona.
A ground-up storage box on a growing Phoenix suburban arterial.
A sponsor came to our feasibility study company with a ground-up, climate-controlled self-storage project and an SBA 504 lender that needed the projected cash flow independently tested before it would commit its first-mortgage position. The subject is a single-story, fully climate-controlled facility of roughly 75,000 net rentable square feet (about 625 units) on a ~3.5-acre pad on a commuter arterial in a fast-growing outer-ring suburb of metro Phoenix. The submarket is genuinely undersupplied on a per-capita basis — Phoenix carries about 5.6 net rentable square feet per capita against a roughly 7.0 undersupply benchmark and a 7.8 national average — but it also sits under a concentrated near-term construction wave.14
Self-storage is income-producing real estate with an operating overlay, not a going concern, so the lender's question is not “what is the dirt worth” but “can this specific site absorb the square footage, at an achievable rate net of concessions, to service this specific loan through a multi-year lease-up.” The SBA treats an owner-operated storage facility as an eligible active business rather than disqualified passive real estate, which is what makes the 504 route available; a ground-up build with no operating history is precisely the condition that turns a discretionary feasibility study into an expected one.11 Our scope was the independent demand, absorption, competition, and debt-service analysis that supports that credit.
Representative and anonymized. Every figure below is illustrative of a typical engagement of this type; the site, submarket, and parties are composited, not a real named borrower, address, or completed transaction.
Square feet per capita, read alongside occupancy and absorption.
The demand read starts with supply per person, not an advertised street rate applied to a unit count. The three-mile ring holds roughly 78,000 residents growing about 3 percent a year, and the existing competitive set works out to well under four net rentable square feet per capita — roughly half the national yardstick.
Supply is measured in net rentable square feet per capita: the national average is about 7.8, with below roughly 6 to 7 reading as undersupply and above 8 to 10 as oversupply.1 Metro Phoenix sits at about 5.6 across 163 facilities and 11.24 million square feet — below the national base — and the subject's three-mile ring is thinner still, at roughly 3.8 square feet per capita against the standing set.4 But the ratio is only half the story: it has to be read alongside actual occupancy and move-in velocity, because a market at low per-capita supply with soft occupancy is still a pass. Here the standing competitors run in the high-80s to low-90s on physical occupancy, confirming that the gap is real demand, not a data artifact. The most consequential number in the pro forma is the rate the model carries: advertised street rates are a poor proxy for achievable revenue because operators discount move-ins hard and then raise existing tenants through the existing-customer-rate-increase (ECRI) cycle — by the fourth quarter of 2024 the in-place rate at the largest REIT ran 74 percent above its move-in rate.6 We underwrote to an achievable stabilized rent between the discounted street rate and the mature in-place rate, not to the headline advertised number.
| Demand driver | Basis | Supported figure |
|---|---|---|
| Trade-area population (3-mi ring) | ~78,000 residents, growing ~3%/yr | Rising captive base |
| Existing supply per capita (3-mi) | ~298,000 NRSF standing set ÷ population4 | ≈ 3.8 SF/capita (vs 5.6 metro, 7.8 U.S.) |
| Stabilized economic occupancy | Undersupplied submarket; REIT low-90s vs 77% all-operator1 | ≈ 90% |
| Achievable rent (climate, net of concessions) | Between discounted street & mature in-place (ECRI)36 | ≈ $15.60/SF/yr ($1.30/SF/mo) |
| Net absorption / lease-up | ~1,800–2,000 NRSF/mo, above the ~1,200–1,500 average-market benchmark7 | ≈ 36-month stabilization2 |
Per-capita, occupancy, rate, and absorption logic grounded in Yardi Matrix, StorageCafe, SSA, and ECRI sources; see sources 1–7. Figures are illustrative of the engagement type.
An undersupplied ring, but the pipeline is arriving.
Five competing facilities sit within three miles, one of them within about a mile, and the ring is undersupplied today. The credit turns on timing: one nearby competitor is already in lease-up and one more is permitted, so the study weighs the current gap against the near-term wave.
| Competitor | Operator tier | Size (NRSF) | Format | Distance | Occupancy read |
|---|---|---|---|---|---|
| Competitor A | REIT-branded | ~72,000 | Climate + drive-up | 1.1 mi | ~92%; mature in-place rates |
| Competitor B | Regional operator | ~58,000 | Mostly drive-up | 1.8 mi | ~88% |
| Competitor C | Independent | ~45,000 | Older single-story | 2.3 mi | ~85%; below-market rates |
| Competitor D | REIT-branded | ~85,000 | Multi-story climate | 2.7 mi | ~62%; in lease-up (opened <12 mo) |
| Competitor E | Independent | ~38,000 | Drive-up only | 2.9 mi | ~90% |
Competitive set surveyed for the engagement; anonymized. Standing set totals ~298,000 NRSF; announced and permitted supply was scanned in addition to the standing set, consistent with lender-grade practice.
Only one competitor sits inside a mile, and it is a well-run REIT-branded box already at mature occupancy on in-place rates — a real anchor, but not one adding capacity. The more important reads are Competitor D, an 85,000-square-foot multi-story facility opened within the past year and still filling at about 62 percent, and one further ~80,000-square-foot facility that is permitted but not yet under construction on the far side of the ring. Counting the full pipeline, not just today's standing set, is the discipline a rigorous study applies: the subject plus Competitor D's remaining lease-up plus the permitted facility would lift the three-mile ring from roughly 3.8 toward the mid-5s per capita — approximately the Phoenix metro benchmark, i.e., roughly equilibrium.4 The conclusion is not that the corner is saturated; it is that lease-up timing governs the credit. We graded the subject's absorption to reflect a competitor filling alongside it, rather than crediting an unobstructed run to stabilization.7
Arizona macro: a growth tailwind, a supply caveat.
The state backdrop is a genuine tailwind for suburban storage demand, tempered by the same Sun Belt supply discipline the sponsor has to respect. Metro Phoenix dominates the state: the Phoenix–Mesa–Chandler MSA reached 5,186,958 as of July 2024, and Maricopa County alone reached 4,673,096, the fourth most-populous U.S. county.
Moving is the single largest self-storage demand driver, and Phoenix has been one of the great in-migration destinations of the last decade — more than 630,000 Californians relocated to Arizona over roughly ten years — which feeds household formation, home-size compression, and the move-in velocity a lease-up depends on.1316 Arizona also carries a business-friendly cost structure: a 2.5 percent flat personal income tax, the lowest flat rate in the country, and a business personal-property exemption rising to $500,000 in 2026, both of which help the operating line on an owner-operated facility.14 Because the state has no general Certificate of Need regime, supply across most asset classes is market-driven rather than permit-gated, so a storage study cannot lean on a regulatory supply brake — it has to carry the full demand burden itself.
The offsetting reality is the near-term pipeline. Phoenix's below-average per-capita base is absorbing a concentrated construction wave — roughly 6 percent of inventory was under construction, and Phoenix was flagged among the metros posting month-over-month street-rate softness — so per-capita comfort must be checked against the specific submarket pipeline before it drives a lease-up curve.5 Two changes cut in the sponsor's favor on the capital side: the SBA's combined 7(a)-plus-504 ceiling rose to $10 million effective July 4, 2026, enlarging bankable deal size, and Arizona's 504 channel is deep, anchored by Certified Development Companies such as TMC Financing — repeatedly named the state's SBA 504 Lender of the Year — and Arizona Capital Source, routing through the SBA's Phoenix district office.1215 Unlike water-intensive housing on the Valley fringe, a storage box is not a heavy water user, so the Assured Water Supply constraint that gates greenfield subdivisions is a minor factor for this asset — a distinction a careful study states rather than assumes.
Why the site captures the submarket.
Rooftop growth, household churn, and arterial visibility all point the same direction, and the site geometry converts that demand into move-ins.
The three-mile trade area carries a median household income in the mid-$80,000s and a wave of new single-family and multifamily rooftops — the household formation, downsizing, and in-and-out moves that generate storage demand. Growth near 3 percent a year means trailing counts understate the captive base, a common exurban distortion a careful study corrects for rather than extrapolates.13 Roughly one in three U.S. households now uses self-storage, and penetration has climbed to about 12.6 percent of all households, so the demand pool widens as the ring builds out.2
Geometry and format do the rest. The subject fronts a signalized commuter arterial with strong drive-by visibility — the single most reliable low-cost source of move-ins for a storage box — and its single-story, drive-up-plus-climate format suits the market: about 44 percent of users now choose climate control, which commands a rate premium and matters in the Arizona heat, while the drive-up perimeter keeps the basis efficient.3 The ~625-unit mix is weighted to the 10×10 and 10×15 sizes that dominate suburban demand, with a smaller tranche of premium units.
The one competitor inside a mile is at mature occupancy and is not adding capacity, so the subject is not splitting a saturated trade area; it is filling a genuine per-capita gap while a newer multi-story box a few miles away absorbs in parallel. That is why the model credits the subject with a defensible ~90 percent stabilized economic occupancy and a graded, competitor-aware lease-up rather than an unobstructed run to fill.
The SBA 504 structure.
Total project cost lands at $6.0 million. The 504 program is purpose-built for owner-occupied fixed assets — a bank first mortgage, a CDC/SBA debenture, and borrower equity — which is why a real-estate-heavy, owner-operated storage facility routes here rather than to a flexible-use 7(a).
| Cost component | Amount |
|---|---|
| Land (~3.5-acre suburban pad) | $0.75M |
| Site work, grading, paving & utilities | $0.65M |
| Building shell & climate-control systems | $3.10M |
| Roll-up doors, FF&E, security & access control | $0.55M |
| Architecture, engineering & permits (soft costs) | $0.40M |
| Contingency | $0.20M |
| Lease-up interest reserve & working capital | $0.35M |
| Total project cost | $6.00M |
All-in ~$80/NRSF, consistent with an efficient single-story climate/drive-up format (hard-cost ranges by format from source 10). Components sum to $6.00M.
| Tranche | Amount | Rate / term | Annual debt service |
|---|---|---|---|
| Bank first mortgage (50%) | $3.00M | ~9.5%, 25-yr amortization | ≈ $315k |
| CDC / SBA 504 debenture (35%) | $2.10M | ~6.5%, 25-yr | ≈ $170k |
| Borrower equity injection (15%) | $0.90M | — | — |
| Total | $6.00M (85% debt) | — | ≈ $485k |
Debt service = loan × annual constant: bank ~0.1049 (9.5%/25-yr) × $3.00M ≈ $315k; debenture ~0.0810 (6.5%/25-yr) × $2.10M ≈ $170k; total ≈ $485k. Structure per SBA 504 conventions under SOP 50 10 8. See sources 11 and 12.
The equity injection sits at 15 percent, not the baseline 10 percent, and that is deliberate: the SBA escalates the required injection for projects that are both special-purpose in character and, as a ground-up build, effectively a start-up, commonly to 15 to 20 percent.11 The 504 structure splits the debt into a conventional bank first mortgage at 50 percent of cost and a below-market, long-term fixed-rate CDC/SBA debenture at 35 percent, which lowers the blended cost of capital versus a single 7(a) note — an advantage that matters on a real-estate-heavy asset carried through a multi-year lease-up. Owner-occupancy is satisfied by operating the facility itself, the test the SBA applies to storage as an eligible active business.11 On the terms shown, total annual debt service is about $485,000 — the number the projected coverage has to clear. The study exists to support exactly that: the debt-service coverage the lender must document to approve the credit, tested against an independent read of demand and absorption rather than the sponsor's own projection.
Feasible and bankable, on coverage the credit can document.
The stabilized model builds effective gross income from rent and ancillary lines, nets an expense ratio in the storage range, and carries the coverage to the SBA floor and beyond — then grades it back down across a three-year lease-up.
| Line | Basis | Amount |
|---|---|---|
| Gross potential rent | 75,000 NRSF × ~$15.60/SF/yr achievable3 | ≈ $1.17M |
| Effective rental income | ~90% stabilized economic occupancy1 | ≈ $1.05M |
| Ancillary income | Tenant insurance/protection + admin & late fees (~8% of rent)6 | ≈ $84k |
| Effective gross income (EGI) | Rental + ancillary | ≈ $1.14M |
| Operating expenses | ~38% of EGI: mgmt ~6%, property tax, insurance, payroll, utilities, R&M, marketing8 | ≈ ($432k) |
| Net operating income (NOI) | EGI less operating expense | ≈ $705k |
Expense ratio held in the storage-typical 35–45% band, with property tax reassessed higher on the completed, leased facility. Stabilized NOI on $6.0M cost is an ~11.7% untrended yield-on-cost — a healthy development spread over prevailing ~5.8% stabilized storage cap rates. See sources 3, 6, 8, and 9.
| Year | Stage | NOI | Debt-service basis | DSCR |
|---|---|---|---|---|
| Year 1 | Lease-up (~40% avg occ.) | ~$245k | Permanent ~$485k; interest reserve bridges | 0.51 |
| Year 2 | Building (~70% occ.) | ~$558k | Full ~$485k | 1.15 |
| Year 3 | Stabilized (~90% occ.) | ~$705k | Full ~$485k | 1.45 |
DSCR computed as NOI divided by the ~$485k period debt-service obligation. See source 7 for the DSCR-across-lease-up convention and source 11 for the ~1.15x SBA coverage floor.
The stabilized 1.45x coverage is the figure the lender documents, and it clears the SBA's roughly 1.15x floor with real headroom — and also the ~1.25x that conventional and agency storage lenders test across the lease-up years.711 By Year 2 the project already covers fully amortizing debt service at 1.15x. The Year 1 figure of 0.51x is intentionally below the floor — it is the ramp year — which is exactly why the structure carries a lease-up interest reserve, funded within the project budget, to bridge the shortfall until the facility reaches its supportable fill. Modeling stabilized occupancy on day one, or a sub-24-month lease-up against a 36-month market average, is one of the most common ways a storage pro forma fails review; the ramp here is deliberately graded and competitor-aware, at an absorption pace of roughly 1,800 to 2,000 net rentable square feet a month.27
On the equity side, the 15 percent injection earns thin distributions through the reserve-covered ramp, then a stabilized cash flow of roughly $220,000 a year once fill is reached. The exit is valued on the income approach, the way storage is underwritten: holding stabilized NOI roughly flat rather than trending it aggressively, and applying a conservative exit cap that reflects Sun Belt storage supply risk rather than crediting cap-rate compression, then netting selling costs and the outstanding SBA balance, the blended result is an illustrative levered equity IRR of about 17 percent over a 10-year hold. The figure is deliberately conservative: it is what the deal supports before any rate-driven value creation, which is the read a feasibility consultant owes a lender rather than the sponsor's upside case.9
Verdict: financially feasible and bankable. On independently derived per-capita demand, a graded 36-month lease-up, a stabilized 1.45x DSCR, and a ~17% illustrative levered equity IRR, the projections support the SBA 504 credit.
Independent demand, absorption, competition, and DSCR stress.
The engagement was scoped the way a credit committee reads it. As an independent feasibility consultant, our role is to test the sponsor's projection against the market, not to restate it — the value of the deliverable is precisely that it carries no stake in the outcome. We derived demand from net rentable square feet per capita read alongside observed occupancy and move-in velocity, never the ratio alone, and we underwrote to an achievable rate net of concessions between the discounted street rate and the mature in-place rate, rather than to the advertised number.6 Absorption was graded to a 36-month, competitor-aware lease-up, with the J-curve leaving Year 1 and Year 2 coverage thin by design.
The coverage analysis was then stress-tested. We ran the debt-service coverage against slower absorption and softer achievable rate — the two variables a lease-up is most exposed to — to confirm the credit still holds if the ring's pipeline fills faster than forecast. One scope boundary is worth stating plainly: as the feasibility consultant, we reference, but do not perform, the Phase I environmental site assessment, and we do not deliver the USPAP value opinion; those are separate professional engagements that run in parallel to the study.11 That combination — independent per-capita demand, graded absorption, a scanned pipeline, and a stressed DSCR — is what lets the lender rely on the file.
Representative engagement
This is an anonymized, illustrative worked example of our methodology, built on market data current to 2026; figures are representative of a typical engagement of this type and do not depict a specific client, site, or completed transaction.
Underwriting an Arizona self-storage facility for an SBA loan? Start with the feasibility study.
Feasibility Study Company prepares independent self-storage feasibility and market studies for SBA 504 and 7(a) credits, built to the coverage standard your lender must document. A methodology briefing walks through the per-capita demand, achievable-rate, absorption, and DSCR analysis behind a case like this one, calibrated to your submarket and format.
Request a methodology briefingData sources and dates.
The deal figures are illustrative of the engagement type; the market data that grounds each dimension is real and sourced, drawn from our standing Arizona, Self-Storage, and SBA 7(a) & 504 analyses and the primary authorities they cite. Storage readings are point-in-time and vendor-dependent; occupancy differs by basis, street rates are not achievable revenue, and supply figures are forecasts as flagged.
- Yardi Matrix (via Multi-Housing News), 2025–2026: national net rentable self-storage supply ~7.8 SF per capita (December 2025); national stabilized occupancy 77.0% (Q4 2025, all-operator basis) versus REIT same-store in the low-90s; national advertised (street) rate +0.3% YoY December 2025; under-construction inventory ~2.6% of stock (November 2025). Undersupply/oversupply thresholds ~6–7 and ~8–10 SF/capita.
- Self Storage Association (SSA), 2025, including the 2025 Self-Storage Demand Study: average time-to-stabilization ~36 months, up from 30; household penetration 12.60% (2024); roughly one-third of Americans currently use self-storage; average length of stay 18.5 months.
- SpareFoot / Storable (2025–2026): average 10×10 non-climate unit ~$119/month and climate-controlled ~$134/month (~$1.34/SF/mo) into 2026; ~52,301 U.S. facilities and more than 2.1 billion NRSF; average facility ~56,900 SF / ~546 units; ~44% of users opt for climate control.
- StorageCafe analysis of Yardi Matrix data (March 2026): metro Phoenix 5.6 net rentable SF per capita across 163 facilities / 11.24M SF; average 10×10 non-climate unit $111/month, −4.3% YoY. Trade-area per-capita figures for the subject ring are illustrative of the engagement.
- RentCafe analysis of Yardi Matrix data, Phoenix self-storage pipeline (2026); Multi-Housing News citing Yardi Matrix: Phoenix under-construction stock ~6.1% of inventory and flagged among metros posting a month-over-month street-rate drop (2026).
- Inside Self-Storage, “The ECRI Evolution” (2025), and Public Storage Form 10-Q (September 30, 2025): existing-customer-rate-increase (ECRI) model; move-in (street) rate down ~33% Q2 2022–Q4 2024; Q4 2024 in-place rate 74% above move-in; ECRI cadence every six to twelve months; tenant-insurance / protection income ~5–10% of revenue.
- Radius+ and MMCG: lender-grade net-absorption benchmark ~1,200–1,500 net rentable SF/month in average markets (up to ~1,500–3,500 in strong Class A markets); break-even occupancy ~65% including debt service; DSCR ~1.25x tested across the lease-up years, not just at stabilization.
- CalcBee and industry compilations: self-storage operating-expense ratios ~35–45% of effective gross income; management fee ~6% of revenue; property taxes the largest single expense, frequently reassessed higher once a new facility is built and leased.
- Cushman & Wakefield (H1 2025): self-storage cap rates ~5.8–5.9% (Class A ~5.0–5.5%, Class B ~5.5–6.5%, weaker secondary assets ~8–10%); average value peaked $174/SF (Q1 2023) and declined to $159/SF (Q2 2025).
- Loan Analytics (2026) and multiple builders: development hard-cost ranges by format (drive-up ~$45–65/SF; single-story climate ~$65–85/SF; multi-story climate ~$85–130/SF; all-in ~$65–170+/SF), framing the subject's ~$80/NRSF all-in basis.
- U.S. Small Business Administration, SOP 50 10 8 (effective June 1, 2025) and 13 CFR 120.160(b): a feasibility study is discretionary but expected for special-purpose and ground-up projects; owner-operated self-storage treated as an eligible active business (eligibility dating to SOP 50 10 (5)(C), effective October 1, 2010); owner-occupancy 60% for new construction; equity injection ≥10%, escalated to ~15–20% for special-purpose and start-up projects; SBA/504 DSCR convention ~1.15x; Small Loan threshold reduced to $350,000.
- SBA 504 program structure (bank first mortgage + CDC/SBA debenture + borrower equity) and SBA Policy Notice 5000-879058 (dated May 18, 2026; effective July 4, 2026): combined 7(a)-plus-504 loan cap raised to $10 million.
- U.S. Census Bureau, Vintage 2024 Population Estimates: Phoenix–Mesa–Chandler MSA 5,186,958 and Maricopa County 4,673,096 (fourth most-populous U.S. county) as of July 1, 2024; Arizona approximately 7.6 million. Trade-area population and income figures for the subject ring are illustrative of the engagement.
- Arizona Department of Revenue and Arizona Commerce Authority: 2.5% flat personal income tax (Proposition 132), the lowest flat rate in the country; 4.9% corporate rate; business personal-property exemption rising to $500,000 in 2026; National Conference of State Legislatures on Arizona as a non-Certificate-of-Need state.
- U.S. Small Business Administration, Arizona District Office directory (Phoenix, with Tucson and Show Low branches); TMC Financing (“Arizona SBA 504 Lender of the Year”; 155 Arizona 504 loans / $543M over a two-year window) and Arizona Capital Source (rebranded Business Development Finance Corporation); sbalenderdata.com computed from the SBA 7(a) FOIA dataset (Arizona 7,055 loans / $4.37B, FY2020–Q1 FY2026; Live Oak Banking Company leads by dollar volume).
- StorageCafe, Migration Trends report (November 2024, analyzing U.S. Census county-to-county data 2013–2022): more than 630,000 California-to-Arizona movers over the period; moving is the single largest self-storage demand driver, making in-migration a primary lease-up catalyst.