When land is scarce, self-storage developers are forced to get creative. In fact, it’s one of the main reasons for building vertically. But there are lot of important things to consider with multi-story construction. For example, you need to pay attention to building types, elevator placement, tenant flow, item loading and unloading, code requirements and more. Design and construction are much more complex with multi-story than single-story.

Single-story projects are simpler and far cheaper to build than multi-story; but sometimes you don’t have much of a choice. If you’re going to build up, you must rise to the challenge! Keep the following in mind.

Size

Most self-storage developers would agree that all of the easy sites on which to build are gone. There simply aren’t any flat, 5-acre lots in high-density areas anymore. What remains are infill lots and teardowns, and these challenging parcels require vertical options to yield sufficient square footage.

Project viability boils down to whether you have enough square footage to be profitable. To determine the stories required, take the total amount of required storage and divide it by the available building footprint. I typically recommend a yield of approximately 80,000 net rentable square feet. Anything less won’t generate sufficient revenue, and too much can drive the build basis up too high and contribute to market saturation.

I suggest keeping your structure to three stories or less to allow for a type II-B construction, which has manageable costs for fireproofing and egress accommodations. Once you reach four stories, the building type typically changes, and costs per square foot increase dramatically.

Zoning

When it comes to getting project approval, complying with government protocols can be tricky. When you approach the authorities for the requisite permits, you’ll often find they don’t have an issue with your multi-story building, but they want it to look more like an office or other commercial structure than a self-storage facility. In many cases, developers wind up spending additional for items that aren’t necessary to the building’s function. For example, the municipality may mandate that the structure include particular fixtures such as windows. Your architect is responsible for making the building simple and functional, but also attractive in the eyes of local government.

Cost

With multi-story self-storage, you’ll spend more on your workers. You’ll need a savvy superintendent and a much larger team because it takes more man hours to handle the complex tasks involved.

You’ll also spend more on building materials. The ratio of exterior skin to rentable square feet is quite high on a multi-story project, so a large portion of your budget will be allocated to the building envelope. Controlling costs is a key responsibility of the development team. An architect can make any storage facility look good, but aesthetics and affordability are often at odds.

This is especially true when using traditional storage materials, such as CMU (concrete masonry unit) block, corrugated metal panels and an intentional lack of fenestration. It can be advantageous to apply high-cost treatments where they’ll get the most exposure and add the biggest value. If applied surgically, features like screen walls, panelized systems, faux shutters and other architectural embellishments can improve appearance greatly without breaking the bank.

Design

With single-story self-storage, design tends to be simple and consistent. You typically use the same materials, and procuring them is very cost-effective. There’s usually a prefabricated metal building, with corrugated metal panels for the walls, metal studs for the structure, and a simple roof. The average facility is 90 percent metal, with a concrete slab.

In contrast, multi-story development is diverse. These facilities can be built in endless ways. The modern complication is they’re often required by the municipality to blend in with their surroundings. This means buildings often feature an intricate design and several materials.

One of the key factors in multi-level design is elevator placement. I recommend you address this very early in the design process. Placement is a delicate balance between tenant convenience and revenue, and may require several revisions.

You need to consider elevator proximity to the loading/unloading area, and whether you’ll price units based on travel distance. Larger units typically yield lower rent per square foot, yet they’re often placed closest to the elevator. This isn’t necessarily a wise approach. You don’t want to inadvertently punish your highest paying customers simply because they’re renting smaller spaces.

Safety

Building more than one story also increases your construction-safety risk. Why? Two reasons: gravity and potential crowding.

Once you go beyond a single level or even two, fall protection becomes a very big deal. As a matter of fact, falling is the leading cause of work-related death, according to the Occupational Safety and Health Administration.

In addition, multi-story sites tend to be somewhat small. There’s less space for workers, equipment and materials to shuffle around, plus a lot of moving parts. This makes it easy for people to collide or otherwise get in each other’s way.

It’s the responsibility of the self-storage development team to ensure proper safety measures are established. At the site, there are many safeguards that must be built or put into place to protect workers. You’ll need to work with an advanced-level contractor, preferably one who has experience in building multi-story self-storage.

A Growing Opportunity

The decision to go vertical requires careful thought. Remember, the major benefit to building multi-story is you’re often able to use land no other developer wants. But because the design and construction process is more complex and expensive than building a single-story facility, make sure you have a capable team in place to ensure success. With the right due diligence, the end result will be a beautiful, well-functioning self-storage facility of which you can be proud.

Jake McMillan is digital strategist for Redondo Beach, Calif.-based InSite Property Group, the parent company of SecureSpace Self Storage and a partner of P.B. Brown, which specializes in self-storage construction. Insite is a fully integrated self-storage developer, builder and operator with a pipeline of more than 20 new facilities under development. Jake focuses on inbound and outbound marketing strategies for the company’s growing portfolio of properties.