By Nicholas Jodhan
During the past three decades, the evolution of the self-storage building type from the traditional garden-variety, single-story facility to the more visible multistory building has given developers pause for thought in the design phase. This evolution has ushered in an era of new design criteria, leaving developers to consider aesthetic and functional aspects as never before. The following factors now play a key role in self-storage design:
1. The product has moved from industrial zoned parcels to business/commercial ones, making the self-storage facility a more integral part of the community landscape. This movement demands the addition of architectural elements, which meet the goals and vision of planning commissions.
2. The change from single-story facilities with exterior unit access to the new multistory properties with internal access makes life safety considerations a priority design criteria. In an emergency, customers must be have quick, easy access to safe exit passages, and sprinkler and alarm systems must adequately protect customers' stored belongings.
3. Although the gross square footage of these new structures has remained roughly the same (plus or minus 100,000 square feet), the vertical vs. horizontal configuration gives rise to considerations for access to units and management of internal foot traffic. Gone are the days of vehicular traffic movement and drive-up unit access as major design considerations.
The design challenges mentioned above are but a few that greet today's self-storage designers and developers. As storage facilities become high-rise structures, the need for an elevator becomes paramount. This article focuses on the challenge of elevator placement in the new facility type.
The elevator is to high-rise structures what the truck is to a single-story building. It is a vertical vehicle that must take clients to the upper floors as readily as the truck took clients to their drive-up units. Although multistory buildings do not offer drive-up access, designers can make it as effortless as possible to get to units on upper floors. To create a truly effective layout with well-positioned elevators, the designer of a multistory site must design with a few fundamental axioms in mind.
Before we can fully understand the inner workings of a building, the selected site and desired building must be configured to conform to all site-related restrictions (lot coverage, setbacks, easements, servitudes, right-of-ways, landscape buffers, detention requirements, parking requirements, etc.). This configuration should be completed first because here is where we discover the criteria for exterior skin options and staircase exit location, as well as site-configuration limitations that force the office and lobby/ elevators into a particular location. A good designer will carefully consider the mandated parameters and should offer several layout options.
Code Compliance and Building Systems
Every municipality will be governed by several zoning, building, life-safety and ADA codes. Be they federal, national, state or local, these codes must be thoroughly understood and complied with during the design process. When laying out a multistory building, the designer must understand the building codes, type and system of construction being proposed.
This would allow the designer to lay out building grid lines and strategically place ingress/egress staircases that are life-safety-code driven. He will also be able to place any fire separation or demising walls through the building. The building's exterior could also now receive some additional evaluation that may or may not influence the interior placement of the elevators. Keep in mind that elevator function is suspended in fire-alarm conditions. Elevators are not considered a means of ingress/egress, so their placement is not typically code-driven.
Designing with efficiency in mind is another critical design consideration that can effect elevator placement. In the self-storage industry, individual property is valued on post lease-up (stabilized) net-operating income. Bearing this in mind, it behooves the designer to maximize the net-leaseable square footage of the building. If ever you examined the stabilized value of a facility at 72 percent efficiency vs. 78 percent, you would understand why designing with this objective in mind is so critical.
Placing the elevators in a location that affords maximized building efficiency should be the designer's prime objective. Because unit mixes are unique to each property, there is no standard placement of elevators. However, be aware this does not mean elevators should be placed haphazardly, but rather in a location that does not disrupt efficiency by causing a significant loss of leaseable space.
The type of elevator selected can influence its eventual placement. For example, a hole pneumatic elevator requires that a hole be drilled on site to accommodate the piston. In some instances, these holes could be in excess of 60 feet. The site may have some locations that would prohibit such a hole, but others that would accommodate it. Pneumatic elevators also require rooms to house their reservoirs.
Another elevator type to consider is a traction elevator, which requires specific shaft heights to accommodate its gearing. In buildings with gable roof lines, placing this type of elevator directly under the ridgeline could eliminate any roof penetration and possible future roof leaks. Other features of elevators, such as dimensions, or single or double doors, would also have some impact on design considerations and could play a role in determining the best placement of the elevator.
Give ground-floor access the next weighted value. There is a fair amount of design flexibility here. Elevators can be placed at the exterior wall with doors opening right onto a covered drive or they may be placed inside the building. Potential users of these facilities will view the access to the upper floors as an inconvenience if the ground-floor elevator access is too difficult. If the elevators are clearly visible and accessible upon entry, the general perception is that the upper floors are accessible as well.
Both location options offer particular benefits, such as convenient access, weather protection, security or efficient function. When elevators are set into the building, the distance from the face of the building depends on several design issues. If clients unload their stored items onto a cart and then into an elevator, incorporating a lobby/staging area into the design is a good idea. This gives clients enough space and time to get out of the elements, enter their access code and secure items on the cart before entering the elevators. Staging can range in depth, but 10 feet is a good practical number, particularly when there is more than one person trying to access the upper floors. Staging any deeper tends to be wasted space and can create unit-mix problems on the upper floors.
The next major consideration is foot-traffic movement. Obviously, there must be adequate width for people and carts to move through the facility aisles, but in regard to elevator placement, walk distance is the governing factor. Walk distance is measured from the elevator landing to the furthest unit from all accessible directions. Ideally, walk distance should not exceed 150 feet. In some facilities, that distance may be increased somewhat if the options for elevator placement are severely restricted.
There are several design criteria that must be considered in order to properly place elevators in a storage facility. The controlling factors must be balanced in a way that results in the best product. It is often a delicate balance to strike and a somewhat inexact science. Each property can have variations unique to that property. I suggest using double-sided doors, keeping all structural elements on a 5-foot design module, placing the elevators no more than 10 feet into the building and placing the elevators halfway along the longer dimension of the building. This will lead to the highest efficiency, creating the greatest investment value.
Nicholas Jodhan has been involved in the development of self-storage for the past four years, designing and developing self-storage facilities in several major cities in the Midwest, Northeast and South. He continues to develop creative ways of addressing the new parameters of the modern self-storage industry. Mr. Jodhan can be reached at NGJ1@earthlink.net.