By Charles Plunkett
Multi-story construction has been around for many years in the self-storage industry and has become a mature part of this business. That doesn’t mean things don’t change or there isn’t still more to learn. Following is a brief overview of the advantages and disadvantages to building vertically.
Rentable Square Footage
Multi-story development allows you to use a much smaller piece of property to achieve the desired square footage for your self-storage development. How efficient this is depends on a number of factors including:
- Building setback requirements
- Ingress/egress requirements
- Impervious coverage (how much of the natural surface you’re allowed to cover with impenetrable materials such as concrete)
- Maximum coverage ratios
Assuming setbacks and coverage are not an issue, you can essentially cover most of a site except for the entry drive, a fairly small tenant-parking area in the front, and an unloading area. This type of layout will also be dependent on fire-department requirements and whether safety personnel require access all the way around the building.
Since most if not all of the units in a multi-story building are typically climate-controlled, it’s important to remember this requires access hallways. In addition, you’ll have elevators and equipment rooms as well as stair towers. As a rule of thumb, 75 percent of the total floor area will be rentable space, with the balance being lost to these portions of the building. You’re building the gross square footage, but you’re only able to rent the net leasable area.
One of the more recent developments affecting multi-story construction is a change in building codes. There used to be several different codes, however, they were all merged into the International Building Code (IBC) several years ago. The latest version, 2012 IBC, has been adopted by most cities.