The Self-Storage Operator's Model
Version 1.0 · Updated July 2026 · Instant download · Excel, Google Sheets, LibreOffice and Numbers
A nineteen-sheet self-storage acquisition model in Excel. It solves the loan as MIN(LTV, DSCR, debt yield) instead of grading one you typed in, separates physical, square-foot and economic occupancy, and includes a tenant-cohort ECRI engine no other model in the category has published. Every operating default is cited to a Q1 2026 REIT filing, an industry survey or a named practitioner.
Is this the best self-storage underwriting model for a private buyer?
It is the only one that arrives with the numbers already in it. Nineteen products in this category were examined before this one was built. The free Adventures in CRE model is excellent and costs nothing. Sharpsheets charges $119. ProjectionHub charges $119. Not one of the three ships a single sourced operating assumption — they hand you a calculator and leave you to guess the inputs, which is the part that decides the answer.
The self-storage model vs. a generic real estate proforma
| Generic proforma | This model | |
|---|---|---|
| The loan | You type an amount | Solved as MIN(LTV, DSCR, debt yield) |
| Occupancy | One number | Physical, square-foot and economic, separated |
| Rate increases | A growth percentage | A 36-month tenant-cohort ECRI engine with a 43% guardrail |
| Management fee | Flat % of gross | The greater of % and the contract minimum, plus billed-back items |
| Capex | $/SF reserve | Components with useful lives and an At-close column |
| Property tax | Held constant | Resets on sale, and moves with the price on the sensitivity ladder |
| Operating assumptions | Blank | Cited, dated and challengeable |
What the sample deal shows
The model ships with a 465-unit, 54,750 net rentable square foot Class B facility asking $5,950,000. It is deliberately a deal you should not buy at that price, because a demo that returns a triumphant green number teaches nothing.
- The flyer's cap rate rebuilds to 6.54%. On your basis it is 5.31% — 124 basis points, gone.
- The loan is sized by DSCR at $2,971,719, not by the 70% LTV you assumed — $1,193,281 of equity nobody planned for.
- Expenses run 45.35% of effective gross income against a 28.92% four-REIT floor.
- Break-even economic occupancy is 68.0% against 74.3% actual: 29 units of cushion.
- To own a 6.25% cap on your own numbers you pay $5,213,565, or $95.22 per net rentable square foot — a $736,435 gap, 12.4% of the ask.
The benchmarks, and where each one came from
| Assumption | Default | Source |
|---|---|---|
| Total operating expenses | 38% of EGI | Five private-market sources, against a 28.92% four-REIT floor |
| Property taxes | 10.97% of revenue | PSA, EXR, CUBE, NSA — Q1 2026 same-store |
| Management fee | 6% or a $1,500–$3,000 monthly minimum | Industry survey of third-party managers |
| Tenant insurance attach | 60%, range 25–90% | Trade publication; lease-compliant vs optional programmes |
| Concession loss | 8% of gross potential | Rises to 16–24% where average stay is under a year |
| Going-in cap, Class B | 5.5–7.0% | Cushman & Wakefield, Inland, tier tables |
| 10-year fixed debt | 7.03% | Quoted 27 July 2026 — update it |
| Lease-up absorption | 2.25% of NRSF/month | Corroborated by the 36-month SSA stabilisation average |
Four places where the model says no credible source exists rather than inventing a default: component capex costs and useful lives (roof at 30 years is the only life published anywhere in this literature), the move-out caused by a rate increase, the card share of collections, and production-grade lease-up curves.
Who this is not for
If you are underwriting a ground-up development, this is the wrong tool — it models acquisition with a lease-up ramp, not construction draws. If you have limited partners, the deal-level returns here are the input to your waterfall, not a substitute for it. And if you already know your market's expense ratios cold and can defend them to a lender, take the free A.CRE model; the benchmarks are what you would be paying for.
What is in the box
Buy on Gumroad → · Or take the free two-sheet screen first →
Version history
| v1.0 | 28 July 2026 — first release. 19 sheets, 1,945 non-empty cells, 57 verification checks, zero formula errors. |
Questions
Is this the best self-storage underwriting model to buy?
It is the only one that ships with sourced operating benchmarks. The free Adventures in CRE model is excellent institutional engineering with no numbers in it, and so are the $119 paid models from Sharpsheets and ProjectionHub. If you want the arithmetic, take the free one. If you want to know what a facility actually costs to run and where that figure came from, this is the one.
How is this different from the free A.CRE self-storage model?
A.CRE gives you a blank institutional shell — waterfall, IRR, refinance, sensitivity, all well built and genuinely free. It contains no benchmark defaults, no ECRI engine, no management fee minimum, no component capex calendar, and it grades a loan you type in rather than solving for it. This model does those five things and cites every default.
What is ECRI and why does it matter in a self-storage model?
Existing customer rate increases — raising rent on tenants already in place. It is the largest operational lever in self-storage and it is why asking rents run around $1.40 per square foot per month while in-place rents run around $2.00, a 43% spread. A model that projects revenue off street rates with no ECRI engine will systematically understate a stabilised facility.
What expense ratio should I use for a self-storage facility?
The four public storage REITs ran 28.92% in Q1 2026 — Public Storage 26.12%, Extra Space 29.75%, CubeSmart 30.34%, National Storage Affiliates 29.47%. Do not use that. It is the institutional floor: REITs self-manage, and fixed costs do not scale down to a $600,000 revenue line. Private third-party-managed facilities run 30–50%. This model defaults to 38% and shows the REIT floor beside it with the citation.
Does it work in Google Sheets?
Yes. Built with INDEX, MATCH, SUMPRODUCT, SUMIFS, OFFSET, MIN, MAX, IRR and IFERROR only. No XLOOKUP, FILTER, SORT, UNIQUE or SEQUENCE, because those break in LibreOffice and in older versions of Excel.
Can I edit the formulas?
Yes. Nothing is locked, nothing is hidden and there are no macros. If you disagree with a formula, open it and change it.
Does it model self-storage development or ground-up construction?
No. It is an acquisition model with a lease-up ramp for expansions and under-occupied assets. It does not model construction draw schedules or a partnership waterfall.
Will the assumptions go stale?
Yes, and the model says so. Every figure is dated 28 July 2026 and the debt rate sits on the face of the debt sheet specifically so you update it.
Is there a refund policy?
Yes. If it does not do what this page says, email runbooksupply@gmail.com and you get your money back.