Self-Storage Proforma

The foundation of any self-storage pro forma is Net Operating Income (NOI). You start with Gross Potential Rent (GPR), which is the total annual rent if every unit were occupied all year. Calculate this by multiplying the total rentable square footage by the projected annual rent per square foot. For example, a 50,000 square foot facility at an average of $18 per square foot annually ($1.50/month) has a GPR of $900,000. This figure represents the maximum theoretical rental income before accounting for real-world factors like empty units or operational costs.

Next, adjust GPR to find Effective Gross Income (EGI). No facility is ever 100% full, so subtract losses from vacancy (empty units) and credit loss (unpaid rent). A typical combined loss factor for a stable property is 10-15%. From this new total, you subtract all Operating Expenses (OpEx)—property taxes, insurance, management fees (often 4-6% of EGI), utilities, and marketing. The final result is your NOI: the property's pure profit before accounting for loan payments. It is the single most important number for determining value.

Let’s underwrite a deal. Imagine a 60,000 sq. ft. facility with a projected market rent of $1.60 per sq. ft. per month. This gives us an annual Gross Potential Rent (GPR) of $1,152,000 (60,000 x $1.60 x 12). Applying a 10% factor for vacancy and credit loss reduces income by $115,200, leaving an Effective Gross Income (EGI) of $1,036,800. We project operating expenses to be 30% of EGI, a common industry benchmark totaling $311,040. Subtracting these expenses from EGI gives us a Net Operating Income (NOI) of $725,760 for the year.

With our NOI of $725,760, we can value the facility. If comparable properties in the area are trading at a 6.5% capitalization (cap) rate, we can estimate the property's value. Dividing the NOI by the cap rate ($725,760 / 0.065) suggests a value of approximately $11.17 million. To assess its debt capacity, assume a total annual loan payment (debt service) of $550,000. The Debt Service Coverage Ratio (DSCR) is 1.32x ($725,760 / $550,000). Since most lenders require a DSCR of at least 1.25x, this deal meets a key bank underwriting metric.

A frequent mistake is being too optimistic with income. Using “pro forma” rents that are much higher than current market rates without a data-backed plan is a recipe for failure. Similarly, assuming a low 5% vacancy rate from day one on an unstabilized property is unrealistic; lease-up takes time. A sound pro forma uses rents from direct competitors in the immediate submarket and a vacancy rate that reflects the property's current occupancy or a conservative lease-up period. Ground your numbers in reality, not hope, to avoid a performance shortfall after you close.

On the other side, underestimating expenses is just as damaging. First-time investors often forget to budget for a Capital Expenditure (CapEx) reserve for major replacements like roofs or paving. A typical reserve is $0.15-$0.25 per square foot annually. Another common blind spot is failing to account for property taxes reassessing at a higher value after the sale. Finally, always include a line item for professional management fees (4-6% of EGI), even if you plan to self-manage. A future buyer will absolutely factor this cost into their valuation, so you should too.

While an average rent per square foot offers a quick estimate, a detailed analysis requires a unit mix breakdown. Not all space is equal. A facility's income potential is driven by the specific number of 5x5s, 10x10s, and climate-controlled units it has. A small, high-demand 10x10 unit might rent for $1.80 per foot, while a larger 10x30 unit rents for only $1.40 per foot. Analyzing the pricing for each unit type in your market provides a far more accurate revenue projection than a simple blended average. This detail is critical for an accurate forecast.

Don’t overlook ancillary income. Modern storage facilities often generate 5-10% of their revenue from sources other than monthly rent. These include late fees, administrative fees, truck rentals, and the retail sale of moving supplies like boxes, tape, and locks. The most significant contributor is often commissions from tenant insurance programs. When you build your pro forma, including a conservative estimate for "Other Income" based on industry norms or the property's actual history makes your forecast more robust. This extra income flows directly to the NOI, boosting your property's value and cash flow.