Planning a self storage unit mix
Your unit mix is the list of unit sizes and types you build, and how many of each. It decides how fast you lease up and how much rent the building earns. A good mix matches what local renters need. A bad one leaves large units empty while small units sell out. This guide walks through the inputs, the trade-offs and a simple way to test a mix.
What a unit mix includes
A mix is more than sizes. Each unit type has several features that change its rent and demand.
- Size, such as 5x5, 5x10, 10x10, 10x15, 10x20 and 10x30
- Climate controlled or not
- Drive-up access or interior hallway
- Floor level and elevator access
- Special types: parking spaces, wine storage, lockers, business units
- Accessible units required by the ADA
Mix decisions are hard to change later. Interior walls can move, but drive-up buildings are fixed. Plan carefully before construction.
Start from local demand
Use your feasibility study as the base. It should describe who will rent and what competitors offer.
- List competitors within your trade area.
- Record each competitor's sizes, prices and which sizes show no availability.
- Note which competitors offer climate control and drive-up units.
- Look at the housing mix: apartments, single-family homes, students, military.
- Look at local businesses that may need larger units.
- Ask a local operator which sizes rent first.
Sizes that are sold out at competitors point to unmet demand. Sizes always available point to oversupply. Specific industry benchmarks for size distribution: [SOURCE NEEDED].
Small versus large units
Small units usually rent for more per square foot. Large units rent for less per foot but take fewer doors and less hallway.
| Factor | Smaller units | Larger units |
|---|---|---|
| Rent per square foot | Usually higher | Usually lower |
| Construction cost per foot | Higher: more walls, doors and hallway | Lower |
| Number of tenants | More, spreading risk | Fewer |
| Management work | More move-ins, more billing | Less |
| Typical renter | Apartment dwellers, overflow | Home moves, businesses, vehicles |
Verify rent-per-foot patterns with your own competitor survey. Do not assume them.
Climate control and drive-up
Climate control costs more to build and operate. It can command higher rent in some markets. Drive-up units are convenient for heavy items and businesses.
The right split depends on climate, competition and renter type. Price each option from real bids. See our cost to build guide.
Converting a multi-story building usually means mostly interior climate-controlled units. See converting a building to self storage.
Accessible units
The ADA sets a minimum number of accessible storage spaces. The 2010 ADA Standards, Table 225.3, require 5 percent of spaces for facilities with 1 to 200 spaces. Above 200, you need 10 plus 2 percent of units over 200.
Section 225.3.1 requires accessible spaces to be dispersed across the classes of spaces provided. That means across sizes and types, not only small units.
Test a mix with the numbers
Build a simple table for each proposed mix. Compare total rentable square feet and potential rent.
Use the same table to set opening prices. See setting rental rates for a new facility.
Common unit mix mistakes
Most mix problems come from copying another facility or guessing. A few habits prevent them.
- Copying a competitor's mix without checking which of their sizes sit empty
- Building too many large units because they are cheaper per foot to build
- Ignoring business renters who need drive-up access and wide doors
- Placing large units on upper floors far from elevators
- Treating accessible units as an afterthought instead of planning them by class
- Skipping a phased plan that lets demand guide later buildings
A simple planning sequence
- Survey competitors and record sizes, rates and availability.
- Draft two or three candidate mixes for the same building area.
- Run the rent table for each mix using surveyed rates.
- Ask your architect what each mix costs in walls, doors and hallway.
- Pick the mix with the best rent after cost, then sanity-check it with a local operator.
- Count accessible units and spread them across classes.
- Revisit the mix before each later construction phase.
Write down why you chose each size. When occupancy data comes in, you can see which assumptions held. That record makes your next phase or next facility faster to plan. More planning topics sit in our start or buy pillar.
Build in flexibility
- Use movable partition systems in interior buildings where possible.
- Phase construction so later buildings can follow actual demand.
- Leave space to add parking or larger units in a later phase.
- Track occupancy by size every month after opening.
Your management software should report occupancy and waitlists by unit type. That data guides the next phase.
Revisit the mix after opening
Your opening mix is a forecast. Real demand shows up in the first months. Review move-ins, move-outs and waitlists by unit type each month. If one size stays full, raise its rate or plan more of it. If one size stays empty, test a lower rate or convert it if partitions allow. Keep notes on each change so you can tell what worked. These reviews feed your next phase and your pricing decisions.
Frequently asked questions
What is the most common unit size?
It varies by market. Use your competitor survey to see which sizes sell out locally. [SOURCE NEEDED] for national size data.
Should all units be climate controlled?
Not always. It depends on local climate, competitors and renter needs. Price both options from bids.
How many accessible units do I need?
Under ADA Table 225.3, 5 percent for 1 to 200 spaces, and 10 plus 2 percent of units over 200 above that.
Can I change the mix after opening?
Interior partitions can often be reconfigured. Drive-up buildings are much harder to change.
Should I add vehicle parking?
If zoning allows it and local demand exists, parking can use land that would otherwise sit idle. Check lien rules for vehicles first.
How do I survey competitor unit sizes?
Visit or call each competitor in your trade area and check their websites. Record each size, its street rate, and whether it is available. Repeat the survey a few weeks later to see which sizes stay sold out.