Most of us have been to a professional sporting event and sat in seats that, while comfortable, could have used a little more leg room. We’ve no doubt wondered why the designer of the stadium or arena couldn’t have given us just a couple more inches between the rows. While a couple of inches for one row of seats doesn’t seem like much, multiply it by dozens of rows and the impact on the total number of seats in the stadium or arena becomes significant.
In short, the owners of the sporting franchise want to maximize the amount of rentable space (seats) while providing adequate, but not excessive, space for the customers. As owners and operators of self-storage, our goal should be the same.
In maximizing the amount of rentable space, the most overlooked factor is the unit-mix layout. Since income is derived from renting storage space, it is fundamental to maximize rental areas and minimize common areas such as office space, lobby and access corridors. This is not much of an issue when developing a traditional drive-up facility, but becomes increasingly important as the industry moves toward interior climate-controlled units and multi-story properties.
You might think maximizing storage would be an easy proposition, but a surprising number of unit layouts do not incorporate some basic rules that maximize rentable space.
Every development requires a certain amount of common area, and each operator has a different preference. Do you favor a spacious rental office with lots of room for merchandise displays, or want little more than a door and front desk? Is it important to provide packing and moving supplies to your customers? Is the profit margin from merchandise sales worth giving up the rentable space? The answers to some of these questions depend on the marketing strategy for your particular location.
Does the customer’s perception of quality require a large rental office? Are your target customers so budget-conscious that a large office sends the wrong message? These are questions that affect how much of the total area will be used for the rental office/common area. Although this is an important consideration, it is not the factor that has the greatest effect on layout efficiency.
Most self-storage layouts are based on a 5-foot grid system, and a 5-foot-wide corridor is standard in the industry. While narrowing the corridor to maximize storage space may result in more rentable space, customers may not appreciate the more restrictive corridors. Instead, the focus should be in minimizing the linear feet of corridors on each floor plan.
A unit mix with an average unit size of 120 square feet will be more efficient than a unit mix with an average unit size of 90 feet. Since every unit requires frontage on a corridor, a smaller mix with more units will naturally require more linear feet of corridor. Whether a space measures 10-by-10 or 10-by-30 feet, it has 10 feet of frontage on a corridor.
A 5-foot-wide corridor for a 30-foot-deep unit has a ratio of corridor width to unit depth of 5:30, or 0.167. Compare this to a 5-foot-deep unit on a 5-foot corridor, which would have a ratio of 5:5, or 1.00. A 5-foot-wide corridor with units on both sides effectively cuts these ratios in half; therefore, double-loaded corridors should be used wherever possible. Remember, the higher the ratio of corridor width to unit depth, the less efficient the unit-mix layout.
The layout of two unit sizes in particular has a strong bearing on the efficiency of the unit mix―namely 5-by-10 units and 7.5-by-10 units. The tendency by many is to situate the unit with the 10-foot dimension along the corridor. This contributes to an inefficient mix. A 5-by-10 unit with the 10-foot dimension along the corridor has a corridor width to unit depth ratio of 5:5, or 1.00, compared to a ratio of 5:10, or 0.50, if the 5- foot dimension is placed along the corridor. This is illustrated in the diagram below.
The difference for the 7.5-by-10 units is not as profound, but when multiplied by 60 or 80 units, it has an impact. The rule that should be applied is the side with the narrower dimension should almost always be the side open to the corridor. The only exception would be when such a layout would result in support columns falling in the middle of a unit door.
Most storage developers and operators strive to maximize convenience for the customer. This strategy includes minimizing the number of turns required from the elevator to any particular unit. An ideal layout requires only two turns from the elevator to access the majority of the units; however, three turns is not an unreasonable number, particularly if the first turn is the one from the elevator.
Some operators prefer a pass-through elevator design. While this is slightly more expensive, it allows a customer to push the cart through the elevators doors on the bottom floor and then, without changing directions, push the cart off the elevator through the opposite doors on the floors above. Most operators that have installed this type of elevator have received favorable comments from customers.
Efficient unit layout requires “banks” of units be no narrower than 20 feet. This allows for back-to-back rows of 10-foot-deep units. At times, the width of a building may challenge this requirement. In such cases, unit sizes can be shifted between floors to arrive at the most efficient overall mix. Also the depth of units against exterior walls can be varied to allow the interior banks to be no narrower than 20 feet. If the spacing still doesn’t work, one trick that may help is turning corridors in the opposite direction.
Even though the majority of corridors in a particular development may run east-west, there is nothing wrong with turning a section of the units 90 degrees so the corridors run north-south. The primary consideration in doing this is so the number of turns from the elevator and the distance to the units does not become unreasonable.
Cost vs. Profit
The beauty of getting maximum efficiency from a building is that it doesn’t cost much more than an inefficient design but will maximize income. Corridors don’t provide any rent, so eliminate them wherever possible. Recently, a reworked unit mix for a three-story structure resulted in an additional 1,400 square feet of rentable space. That’s the equivalent of adding fourteen 10-by-10 units without enlarging the footprint of the building. The cost increase for doing this was minimal, but the added earning potential was significant.
Not all architects are created equal, and leaving the unit-mix design up to the architect may not maximize unit efficiency. Getting the right layout is like putting together a multi-layered jigsaw puzzle. There are many pieces that can fit together in a variety of ways, but for maximum efficiency, each piece needs to be in the right place. Not everyone has the patience or the understanding of spatial relationships necessary to accomplish this task.
However, by learning these few basic rules about layout efficiency, you can move closer to maximizing the earning potential of your self-storage development. Remember the lesson from the ball park: Make the customer comfortable, but avoid the temptation to add a few extra inches between the rows.
Kent Flake is the owner of Arizona-based Full Circle Storage Consulting, a subsidiary of West-States Storage Group LLC, and has been involved in storage development since 1996. For more information, call 480.202.1669; e-mail firstname.lastname@example.org.