The exit sign—humble, omnipresent, code-mandated—is begrudged by designers. Perched above doors and in the nooks of long corridors, its fluorescent letters glow, gleefully indifferent to any adjacent color palettes, finishes, and details. Though essential in emergency situations, the exit sign is often the bane of architecture practitioners.
“We thought it was an area that was ripe for design,” says Mark Wamble, a founding principal of Houston-based Interloop—Architecture. By stripping the sign down to its core—the four letters, E-X-I-T—he and his team have produced a sleek and elegant revision, now available commercially through Architectural Safety Components. Standard exit signs comprise illuminated metal boxes or side-lit panes of rectangular glass. Interloop found that advancements in LED technology—smaller package sizes, increased luminance, and wider cones of light—would allow the letters to stand alone without any framing or housing. With each stroke fully lit and minimally attached to the mounting armature, the letters appear to float in space.
As a life-safety device, an exit sign is subject to rigorous design standards and operational requirements for its dimensions, its light emission levels, and the strict geometries of its lettering—all of which are mandated by federal law and scrutinized by Underwriter Laboratories (UL).
Meeting these UL standards proved to be a challenge. Working with machinists, electronics manufacturers, and engineers, Interloop went through several iterations to cram enough diodes into the letter forms to achieve the requisite brightness, and to perfect the design of the acrylic and aluminum light housing. For example, the arrangement of the diodes in each colored version of the sign had to be adjusted for the different ways red light and green light disperse, and the interior surfaces of the letter lenses had to be beveled and re-beveled.
“When you make prototypes for UL, you don’t just whip something up in the back room,” Wamble says. Instead, “you engage a half dozen manufacturers and say, ‘Will you please work with us and make some prototypes?’ and ‘This is going to take a while.’ We enjoyed it in a perverse kind of a way. It helped us clarify our ideas.”
Interloop emphasized flexibility. The design attaches the letters to the armature in multiple arrangements, enabling the sign to be mounted from any side (top, bottom, left, right). Factoring in the various add-ons like a storage case for battery backups, different arrow positions, and multiple colors, the sign can be configured in 244 ways.
Having options was important to the team, itself guilty of adding exit signs to their own drawing sets at the last minute, or at the request of a fire marshal. “Architects just … suffer through it,” Wamble says.
The jury celebrated Interloop’s exit sign as a breakthrough for architects. “There’s going to be a widespread cheer [that] goes up in all of architecture,” juror Mic Patterson predicted.
And Interloop is eyeing other life-safety devices, such as strobe lights, fire alarms, and fire sprinklers. “All that,” Wamble says, “is ripe for rethinking.”
Client: Architectural Safety Components
Design Firm: Interloop—Architecture, Houston · Mark Wamble, Dawn Finley, AIA (design principals); Eric Hughes, Peter Muessig, Jack Mussett (project team)
Project Adviser: Architectural Safety Components · Sam Youdal
Consultant: Martin Co. · John Martin
Fabricators: Moore Fabrication · Kerry Krumbeck; Professionalized Products and Services · Jerry Huang; Southwest Electronic Energy Group · Alex Marin; Anodizing Graphics of Houston · Linda Sayers
Special Thanks: Underwriters Laboratories · Abdul Ahad (investigating engineer)