"Structural? That's not what I do! I'm an interior designer, and interior designers do not do anything structural; interior designers do not know structures!" Oh really?
I have been an interior design practitioner for 25 years, and my response to this comment is, "It is not whether interior designers know structures, it is that interior designers do not do anything structural … knowingly." This fact is what separates interior designers who are qualified through proper education and experience from designers or persons who are not.
The question to answer is, "How does someone knowingly not do anything structural if they do not know what is structural?" I am reminded of an apocryphal story—an urban legend of sorts— about a designer who demanded the removal of a column because it obstructed his or her furniture layout. I have heard this story countless times, but I have never known of a real person who ever did such a thing. Regardless, the story conveys why interior design professionals must be identifiable and accountable for the building interiors they design: to protect the public.
The un-engineered removal of a freestanding column in any building may appear to be an obvious act of ignorance and is hard to imagine it actually happening. Concealed aspects of a building's structure are, by their nature, not obvious. Structures hidden within walls, floors and ceilings can easily go unnoticed by an untrained person. For example, something as simple as planning for the location of a floor-mounted electrical outlet or a water closet could become problematic if located over a support beam. Such a location would require penetration through the beam—compromising the structural capacity for which the beam was designed. Drilling through could snap the steel tension support system and prove to be a fatal mistake.
On the other hand, certain structural prerequisites should be assumed. For instance, specifying a chandelier to be mounted on a ceiling or designing cabinets to be fastened to a wall without providing for any structural support to carry the loads would no doubt cause structural failure and potential harm to the occupants.
Knowing a building's structural limitations is also very important. Proper planning to ensure that floor loads don't exceed the building's design is critical when planning for dense file areas, heavy equipment or even hot tubs. Are interior designers trained to calculate floor loads? No, but they must know that there are limitations, and they must recognize which professional to consult when questions of structure and loads arise—and incorporate appropriate design changes, as designed by an allied professional—to ensure public safety.
Interior designers should be cognizant of the many circumstances under which the design of a space can affect the building's structure. To protect the structure of the building they must plan spaces so they "knowingly" do not affect the structure. They must have an understanding of floor joists, beams and columns and how they fit together to make a building. They must have an understanding of what load-bearing walls and non-load-bearing walls are; and, if in the design process a structure must undergo modification, the interior designer must know who to consult and when, before a design solution is finalized. To do anything less would put the public at risk.
The interior designer who removed a column in our urban myth most likely consulted with a structural engineer or architect to determine what type and size of beam and columns could be installed to offset the loss of the errant one. If he or she did not follow that course, then I propose the person was not a qualified interior designer. But, since there is only interior design legislation to protect the public in 50 percent of the United States, then there is a 50/50 chance I am wrong. Ah, but that is fodder for another column!
Kimberly Marks is a director on the NCIDQ board and a practicing registered interior design in Texas. A national speaker and author, she wrote NCIDQ's monograph, "Structures in Interior Design." For information about Marks' publications and upcoming speaking engagements, go to www.buildingcodesforinteriors.com. For more information on NCIDQ, visit www.ncidq.org.