February 1, 1998

8 Min Read
Multilevel Design Considerations

Going Up?

Multilevel Design Considerations

By Cecile Blaine

Twenty years ago, the mere mention of self-storage conjured upan image of a long line of one-story, garage-like units. Today,however, the typical self-storage facility might be housed in aone-story, two-story or even sky-scraping building.

Facilities are growing up.

The very reasons for going to a multilevel sometimes dictatevarious elements of the building's design. Usually more expensiveland creates the need to build up rather than out, as pricierland requires a facility with more earning potential than asingle-story facility--more units and greater square footage inorder to bring in the revenue.

"What makes the multistory more attractive, of course, isthe cost of land," says Herman Menze, a self-storagefacility designer based in Tempe, Ariz.

Vincent High, a sales representative with PioneerInternational Steel Inc. in Austin, Texas, sees a trend in thedevelopment of multilevel facilities. "I am starting to seemore expensive sites, sites located near higher-end residentialcommunities," High says. Those facilities say a great dealabout the changing market. "Whereas the property itself isfairly expensive, people are willing to pay a little more on thedollar to get their unit closer to them."

It makes sense that developers who build on expensive landwill spend more on their facility and will charge higher rentalrates. "The people who are going to spend the money on aproject--on an expensive piece of property where they need tobuild up--generally are going to go high-end. They are going tooffer climate control. They are going to offer all the finerfeatures that you'd find in a self-storage building."

Planning/Project Approval

The height of a facility is directly proportionate to zoningregulations. In fact, if self-storage is still unknown to manyplanning and development departments, multilevel facilitiesconfuse them even more.

"Generally, on the multilevel projects, you need to getapproval from the city," High says. "And you are goingto have to get an architect.

"One thing we find in the multilevel buildings is thereis a bit more planning involved and a lot more of an approvalprocess. You don't want to get too involved in a project only tofind out that it won't be approved. So, there is a lot ofpre-approval that goes on through the counties or cities beforeyou get to the builder. You do have to keep flexibility inmind."

Breaking the Code

Many aspects of design are pre-determined by building codesand regulations--whether national, statewide, county or local.The facility's location dictates its building codes. For example,the Universal Building Code (UBC) reigns in most of the westernstates, Building Officials' Conference of America (BOCA) is usedin the eastern United States, while the state of New York has acode all its own. These national codes determine suchspecifications as roof load, stairwell configuration and theminimum distance between a unit and the nearest stairway. NewYork, on the other hand, is particularly quirky because it is theonly state that requires facilities to have fire hatches with arailing to the roof, according to Jamie Lindau, sales manager ofTrachte Building Systems Inc. of Sun Prairie, Wisc.

"There are a lot of particulars in each state," saysLindau.

The Americans With Disabilities Act (ADA) also requires publicbuildings to accommodate the handicapped, whether that be withramps, parking, special bathrooms or all of the above.

Local fire codes affect sprinklers, fire walls, fire doors andother related specifications, says High. As a general rule ofthumb, he says, a building larger than 40,000 square feet willneed sprinklers and anything more than 16,000 square feet willrequire fire walls approximately every 3,000 feet.

One thing that Menze likes to point out is the love/haterelationship with sprinklers. "The fire departments lovethem," he says. "The managers generally hate them,because they are more afraid of water damage than fire damage.So, as a practical matter, I think the operators have to getaccustomed to them."

In the design of Squaw Peak Mini-Storage in Phoenix, which hasone three-story building, Menze was required to install onesprinkler head for every unit in the facility. The upside ofhaving so many sprinklers meant no fire walls were needed.

Building height is frequently regulated by local authorities,but there are ways to be creative with restrictions. For example,Menze faced a 24-foot building height restriction on the Phoenixfacility he designed. "So, how do you get three floors in 24feet?" he asks with a laugh. He did it by designing abasement into the building with ground-level access, whichbrought it to 24 feet and gave him the number of units needed tokeep to the owner's pro-forma.

"One of the things we did was put the basement two feetabove ground, so our ground-level floor is two feet up,"says Menze. "That way you can back up and unload apickup."

Others, like Lindau, say that basements bring on otherproblems. "With a basement, you have the potential concernof water leaking in, the musty smell," he explains."Sometimes owners will use climate control on that lowerlevel to help take out that musty smell." But more oftenthan not, he says, "you've got a problem. It's a basement;it will smell like a basement."

Mix and Match

Building on more expensive land for a wealthier customer baseoften means building a facility with a unit mix that is lopsidedtoward smaller units; larger units are usually placed on theground floors, with the greater number of smaller units, such as5-by-5s and 5-by-10s, built on the upper floors.

For example, High is currently working on a facility thatincludes a three-story building in which the entire first flooris divided up into 10-by-20s with the second floor housing the10-by-10s, 5-by-10s and 5-by-5s.

Adding levels to the old model of the self-storage facilitymeans that the owner must provide additional amenities to helpthe customer get around, such as dollies, carts and perhaps aloading dock.

Elevator Ride

When taking a facility from a flat string of boxy units to astacked formation, the question of having an elevator comes intoplay.

In his experience, Lindau says a lift is usually included inthe design of a two-story building, while elevators are almostalways built into three-story facilities. The cost difference isapproximately $20,000 for the lift, compared with $50,000 for theelevator, he says.

On the other hand, High says not all Pioneer's two-levelprojects have elevators or lifts. The bottom line, he adds, isthat owners should want to make it as easy as possible forcustomers to get to their units, while staying within the budget.

Just the presence of an elevator points to an upper-scalefacility, a sign of class and convenience. It's just anotheramenity that makes the difference between an average facility andone that caters to a customer base that can support higher rentalrates.

Whether they are required or not, elevators can be added to afacility as an architectural point of interest and to adddimension, as Menze illustrated in his latest project.

Structure Juncture

The structure of a multilevel facility usually has some subtlechanges from that of its one-story brother.

Some builders say that the foundation for a facility withmultiple levels doesn't differ greatly from a single-storybuilding. Others, like Trachte's Lindau, note the increase inmaterials and change in the footings.

"If you only go one to two stories, you use more re-bar,more shovel footings," he says. "You typically are notallowed a floating slab. You need a frost wall or a trench-wallfooting instead. If you were constructing a metal building upnorth, you do not need a footing. But when you go to a two-story,you usually cannot do that. You have to go to the frostline."

As facilities grow taller and taller, construction materialsare increasingly restricted. For example, more flammablematerials such as wood are frowned on as the facility designgrows.

Likewise, whereas single-story facilities sell convenience interms of distance from the customers' cars, provided by theirexterior entrances, upper levels of multilevel buildings aredesigned almost exclusively with interior hallways. That is donefor a number of reasons, the strongest of which is saving spaceand money for climate control.

At Squaw Peak Self Storage, the multilevel facility Menzedesigned, he has created door mullions, headers and end panelsout of structural members in order to strengthen the hallways."This way, you can take a mullion and hit it with asledgehammer and you are not going to hurt it," he says.

Climate Control

In order to maintain higher rents and attract an upper-scaleclientele, multilevel facilities--with interior hallways on theupper floors--are perfectly set up to offer climate control.Larger, non-climate-control units with the roll-up doors aretypically placed on the ground level with street access. Then,the smaller, upper-level units located on interior hallways haveclimate control.

"The rent you get is 10 to 20 percent higher,"attests Menze, who put evaporative coolers on the ground floorand upper level and standard air-conditioning units in thebasement of Squaw Peak Self Storage to reduce the cost ofcooling.

In a world where convenience is everything, climate control isan added incentive to get customers to take those extra stepsfrom their cars that those upper floors require. "They wantto drive up to their unit, they want to walk two feet and openthe door," he points out. "Anything more than that is ahassle."

Today's multilevel facility design reflects several differentmovements in the market: the scarcity of attractive rural sites,a move to urban markets and a demand for a product located closerto home. The end result has been higher standards than ever.Multilevel design is subject to more building regulations andstronger construction requirements. It has followed a trend ininterior over exterior hallways and has offered the mostsophisticated amenities the industry has known.

So, at least in the case of multilevel facility development,what goes up, doesn't necessarily come down--either in price orin quality.

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