How should a storage facility recommend a unit size?

Recommend a unit from the customer's item list and your own measured units, not a generic size chart. Ask what they are storing, the largest item's actual dimensions and how often they need access. Match that to the interior size, door opening and clear height of the units you have open, and send the recommendation with its assumptions in writing.

Why generic size charts cause move-in problems

A generic size chart line reads something like "a 10x10 holds a two-bedroom apartment." That shortcut breaks for three reasons.

• Nominal sizes are not interior sizes. A unit sold as 10x10 can measure less inside once walls, posts and door tracks are accounted for. Ceiling height can change from building to building at the same facility.
• Door openings are smaller than units. A roll-up door on an interior hallway unit can be much narrower than the unit itself. A sofa that fits the floor may not fit through the door.
• People pack differently. Someone who needs to reach their things every month needs an aisle. Someone storing for a year can pack wall to wall.

When the recommendation is wrong, the cost shows up on move-in day: a transfer to a bigger unit, a second trip with the truck, staff time spent on rework, and a customer whose first experience was a problem. None of that requires a statistic to see. It is the reason to recommend from measurements instead of from a chart.

The workflow, from first question to move-in

Step	Owner	What happens	Output
1. Intake	Whoever answers: front desk, phone, web form	Collect the item list, the largest item's dimensions, access frequency and move-in date	Completed intake note
2. Estimate	Front desk	Turn the list into floor area and height, and flag items that cannot be stacked	Rough square footage and a tallest-item height
3. Match	Front desk	Compare against measured units that are available now, including door size and access type	One primary unit and one fallback
4. Recommend	Front desk	Tell the customer the unit, the reasons and the assumptions	Written recommendation
5. Confirm	Front desk	Send the summary by text or email before the customer rents	Customer has the dimensions in writing
6. Exception	Manager	If it does not fit at move-in, apply your transfer policy the same day	Transfer or adjusted plan, with notes

Two rules keep this from becoming slow. First, step 1 should take a couple of minutes with a standard set of questions (see the checklist below). Second, the manager handles only exceptions, so the front desk can recommend without waiting for approval.

Measure your own units once

The match step only works if you know your real dimensions. Walk the property once and build a unit sheet. Re-measure when you renovate, convert units or add buildings.

Field	Why it matters	Example entry
Unit type and nominal size	What the customer sees on your rate sheet	10x10, interior hallway
Interior width and depth	Real floor area for the estimate	9 ft 8 in x 9 ft 10 in
Clear height at the lowest point	Beams, sprinkler heads and lights limit stacking	7 ft 6 in
Door width and height	Decides whether large items get in at all	3 ft 6 in x 7 ft
Access type	Drive-up, ground floor interior, or upper floor by elevator	Ground floor interior, 60 ft from loading door
Climate control	Some customers need it for specific items	Yes

The example entries are placeholders. Use your own tape measure. If units of the same nominal size differ between buildings, record each building separately.

Questions to ask every customer

Use the same questions every time, whoever answers. The first five are required; the rest help when the customer has them.

• What are you storing? A rough room-by-room list is enough.
• What is the largest single item, and roughly how long, wide and tall is it?
• Will any items need to stand upright or stay unstacked?
• How often will you need to get to your things? Weekly, monthly or rarely?
• When do you need to move in?
• Optional: Will you arrive with a truck or trailer? This affects whether drive-up access matters.
• Optional: Is anything sensitive to heat, cold or humidity?
• Optional: Do you expect to add or remove items over time?

If the caller cannot answer the largest-item question, say so in the intake note. It can change the recommendation more than any other answer.

A worked example (hypothetical)

This example is invented to show the arithmetic. The customer, items and unit dimensions are not from a real facility.

A customer is leaving a one-bedroom apartment for a few months. They will need to get in about once a month. Their list:

• A sofa, 84 x 36 inches, about 34 inches tall
• A dresser, 60 x 20 inches
• A queen mattress and box spring, which will stand on edge against a wall, taking about 80 x 20 inches of floor
• 20 moving boxes that measure 18 x 18 x 16 inches, stacked four high
• A bicycle, about 70 x 24 inches

Floor area, rounded:

Item	Footprint	Square feet
Sofa	84 x 36 in	21.0
Dresser	60 x 20 in	8.3
Mattress and box spring on edge	80 x 20 in	11.1
Boxes, five stacks of four	5 x (18 x 18 in)	11.3
Bicycle	70 x 24 in	11.7
Total		63.4

The customer needs monthly access, so plan an aisle. A 30-inch aisle running the depth of a unit that is 9 ft 10 in deep adds about 24.6 square feet. The plan needs about 88 square feet.

Now compare against the measured units in this hypothetical facility:

• The 5x10 measures about 45 square feet inside. Too small.
• The 10x10 measures 9 ft 8 in x 9 ft 10 in, about 95 square feet. On floor area alone, the plan fits with roughly 7 square feet to spare, and the stacked boxes reach 64 inches, under the 7 ft 6 in clear height.
• The 10x15 fits easily, at a higher monthly rate.

Floor area is a first screen, not proof of fit. Items are not perfect rectangles, the aisle has to stay clear, and odd shapes like a bicycle or a sofa with arms rarely pack flush. The arithmetic also says nothing about whether the sofa clears the 3 ft 6 in door or can turn from the hallway into the unit. That depends on the sofa's actual depth, height and arm shape, the hallway width and the door's clear opening, so ask the customer for those measurements and check them against your unit sheet before you call the unit a fit.

The recommendation: the 10x10 on the stated assumptions, with the 10x15 as the fallback if the list grows, the door check fails or the customer would rather not pack tightly. The written summary lists the dimensions used, says the 10x10 leaves little spare room, and asks the customer to confirm the sofa's measurements against the door before move-in.

That summary also protects the customer. If they arrive with a second dresser, everyone can see why the plan changed.

Common problems and what to check

These are likely causes, not proven ones. Check them against your own transfer and move-in notes before changing your process.

Symptom	Likely cause	What to check	Fix
Customers transfer to a bigger unit in the first week	Recommendations based on a chart or the lowest advertised rate	Intake notes for transfers: was there an item list?	Make the largest-item question required
Large items do not fit through the door	Door sizes were never recorded	Your unit sheet	Add door width and height for every unit type
Two staff members recommend different sizes for the same list	No shared method	Compare two recent recommendations	Use the unit sheet and checklist for every call
Online renters choose units that are too small	Listings show only nominal size	Your website or rental page	Show interior and door dimensions where your listing allows it
Customers rent too large and move out early	Fear of the unit being too small, without an estimate	Move-out reasons	Share the estimate and the spare room in writing

What to track

If you keep one number, count move-in transfers to a different unit size within 14 days, divided by move-ins in the same period. Read the intake note for each one. The notes tell you which question was missing.

Where Propty fits

Size questions can arrive by phone while staff are on the property. Propty's self-storage page describes answering calls day and night with an approved greeting, quoting only from your rate sheet and texting back missed callers. What it could tell a caller about units would depend on the unit information it is given, so the unit sheet above is worth building either way. These descriptions come from Propty's public pages as checked on 2026-10-14. They are not a test of the live product. What is available for a property depends on setup and connected services, so confirm current behavior in a demo before relying on it.

See how Propty works for self-storage, see the self-storage demo, or read more self-storage answers on Propty Learn.

Sources

• Propty for self storage: product statements used in "Where Propty fits" (answers every call 24/7 with an approved greeting, quotes only from the rate sheet, texts back missed callers).
• No outside statistics are used in this article. All dimensions and figures in the example are hypothetical, and the arithmetic is shown.