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Storage Income Calculator

On-site storage adds high-margin ancillary income that flows straight to NOI. This calculator sizes monthly revenue from 5x5, 5x10, and 10x10 cages with occupancy and tenant insurance attach, then prices the contribution at your cap rate.

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Lighting, security, billing

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Monthly storage income

$1,656

Storage rent (after occupancy)

$1,556

Insurance attach margin

$101

Annual gross income

$19,878

Storage NOI

$15,678

Valuation at cap rate

$241,196

Annual revenue per unit

$904

How the math works

On-site storage is the second highest-margin ancillary income behind parking. Multifamily buildings convert hallway closets, basement rooms, and garage corners into rentable storage at $40-$200/month per unit. Occupancy reaches 80-95% in dense urban markets and 60-75% in suburban garden-style. Tenant insurance attach (a captive program) adds 10-15% to revenue with minimal operator effort.

Unlike parking, storage benefits from compounding: tenants accumulate stuff and rarely move out of storage even after they vacate the unit. Average storage tenancy is 18-26 months. CapEx to convert unused common space is typically $400-$900 per cage including lighting and security; payback is 6-18 months at typical rates.

How to Use

  1. Enter unit count and rent for each storage size.
  2. Set realistic occupancy (most buildings run 80-90%).
  3. Enter tenant insurance attach rate and your monthly margin.
  4. Enter annual operating expenses (lighting, security, billing).
  5. Set the cap rate to value the NOI contribution.
  6. Read monthly, annual, NOI, and valuation lift.

Frequently Asked Questions

What's a typical storage rate?

Urban: $50-$80 (5x5), $90-$140 (5x10), $150-$240 (10x10). Suburban: $35-$55, $60-$95, $100-$160. Climate-controlled adds 25-50%. Always benchmark against the nearest Public Storage or Extra Space within 1-2 miles — they set the price ceiling for your captive tenants.

How do I find storage space inside the building?

Underutilized common areas: basement corridors, mechanical room overflow, garage corners, vacant ground-floor rooms. A 5-by-5 cage takes 25 sq ft; a typical garden-style multifamily has 200-1,000 sq ft of convertible space. CapEx for cages, lighting, and security is $400-$900 per unit.

Should tenants need insurance?

Yes — most modern leases require basic content insurance ($2,000-$5,000 limit) with a captive program. Operators earn $5-$12 monthly margin on each enrolled tenant. Insurance reduces operator liability for theft and water damage and creates an additional revenue line at near-zero variable cost.

Is storage income captured in the cap rate?

Yes — storage revenue and expenses are operating items and flow into NOI. A property that adds $30k of storage NOI lifts valuation by $30k ÷ cap rate. At a 6% cap, that's $500k of equity creation from a $20k-$30k cage build.

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