Every musical performance is unique, but they typically begin with an identical ritual. The musicians file into their seats and the conductor cues a lone musician to play a specific note. As the concert pitch lingers in the air, the ensemble tunes their instruments to match it, cycling through each one of their strings while building a crescendo to a distinct and harmonious drone. But the delicate adjustments to each instrument aren’t the only things that impact the sound audiences (and musicians themselves) hear during a concert. Architecture plays a huge role–and it, too, can be fine-tuned, just like an orchestra.
Architectural acoustics, as a science, is a relatively young field with its origins in the late 19th century. But over the last century designers and engineers have been able to understand how the composition of a space will affect its aural characteristics with far greater precision and certainty than in centuries past. Architects are now armed with a new tool to mold their spaces to precise sonic specifications: algorithms. In fact, before they even begin designing, architects can work with acousticians to model the ideal sound of a space and come up with a design that meets those criteria by tweaking its shape, materials, and contours.
While algorithms have been used by architects to create mind-boggling facades and other cool formal experiments, the application of generative design to acoustics is a compelling example of how algorithms can help produce more functional (and often less expensive) architecture.
Algorithms played an essential, irreplaceable role in both the design and construction of the University of Iowa’s new Voxman School of Music.
The project, which includes a 700-seat concert hall, an intimate recital hall, rehearsal spaces, classrooms, offices, and communal lounges for both the public and students to enjoy, was complex in terms of its size–but also its budget, since it was funded by millions of dollars of FEMA aid after severe flooding in 2008.
“We do lots of complicated projects,” says Stephen Van Dyck, a partner at LMN Architects, the Seattle-based firm that designed the Voxman School of Music along with the local firm Neumann Monson Architects. “A building like Voxman is among the most complicated projects architects can undertake.”
Designing something at the scale of the six-story building, which clocks in at 184,000 square feet (roughly the same area as three football fields), is challenging enough. But the extra structural engineering, acoustic engineering, theatrical design, sustainability features (the building earned LEED Gold certification), and custom architectural detailing inherent to a space purpose-designed for music compounded that complexity. With 13 different companies consulting on the project, LMN Architects had to think like conductors to pull it all together cohesively. Digital design tools–like algorithms and parametric modeling–became the metaphorical score that mapped out how everything would fit together.
The most acoustically complex space in the building is the concert hall. Look closely at any concert hall or auditorium where musical performances take place and you’ll notice that the walls and ceiling are never flat. The Voxman School of Music–with its contoured walls and ceiling–is no different. A symphonic orchestra, a marching band, an acoustic jazz quartet, an amplified rock band, a solo singer, or any combination of those things could perform in the space. The acoustic design and audio-visual consultants Jaffe Holden worked with LMN to create a space that would be acoustically flexible to accommodate those uses. They wanted to let sound reverberate and linger but also provide intimacy–meaning that regardless of where you’re sitting in the space you can hear the instruments quickly.
The concert hall’s most dramatic gesture is an acoustic reflector that hangs from the ceiling. In addition to shaping the room’s sound, it also hides speakers, stage and house lights, and a sprinkler system for fire safety. Each of these systems has its own set of specifications. Horton Lees Brogden Lighting Design consulted on the lighting and had requirements like being able to illuminate zones on the stage or specific performers.
The only way to juggle all of these parameters, requirements, and specifications? Algorithmic design.
Scott Crawford–a design technologist at LMN and founding member of its Tech Studio, a team that comes up with digital tools for the company–developed the algorithms that the firm used to design the entire building, concert hall included. In a traditional design process, the architects decide on specific measurements for the buildings elements. A wall should be X feet tall, a window should be placed here, a door there, and so on. The difference in algorithmic design is that the programs don’t design to specific measurements; they design to parameters.
“We talk about all these aspects of the design as constraints, but they’re really relationships between pieces,” Crawford says. “When we design algorithmically, we’re specifying the relationships between them. The script is the logic for how things respond to one another.”
At the beginning of a project, the architects don’t know how many speakers or lights or sprinklers are going to go into a project–these details and needs constantly change and evolve. Algorithms help adapt to this change more readily. By designing a dynamic model of the space using parameters based on what these things need to accomplish, architects can easily accommodate new requirements for a project. For example, as long as the stage lighting can illuminate the first chair violinist, it doesn’t matter where it’s placed. The architects can input new information into the model and let it update itself to make sure all the requirements are met, and that the space is visually beautiful and acoustically rich.
These algorithms dictated the shape of the concert hall’s large overhead acoustic reflector, as well as other aspects of its design–like the ratio of opaque and transparent sections, where the apertures should be placed to allow for lights, speakers, and sprinklers, and the form of the balconies and walls in the concert hall itself.
“We would never have designed a ceiling like this without our tools,” Crawford says. “It has 942 panels, none are the same shape. It can get ridiculous when designers brag about the number of unique parts in their work, but it’s not about the number of parts; it’s the specificity of what they need to do, and we could control that with our tools.”
Elsewhere in the building, similar algorithmically mediated balancing acts between acoustic performance and architectural design took place. In the 200-seat recital hall–which has a street-facing, 30-foot-tall wall of windows–the architects and acoustic engineers design a cast-panel system of sound absorbers and reflectors on the ceiling and wall opposite the windows and painted them crimson, which helps make the space visually distinct. A pipe-organ hall features Venetian plaster walls and an ornate screen behind the instrument itself to create warm, reverberant sound. In a practice room, the architects designed a system of suspended metal “kites” to direct sound and also to hang lights and fire sprinklers.
“Proving something seemingly complicated is easy to build, and showing it has secondary functions were really important to what we’re able achieve,” Crawford says. “It’s not just for acoustics and aesthetics, but function too.”
But the complexity of the building wasn’t the only thing driving this novel design process–funding issues also played a role. After floods inundated and damaged existing buildings on the university’s campus in 2008, FEMA awarded the university $83 million to help reconstruction efforts for three fine arts and performing arts facilities. Instead of rebuilding the school of music on its campus, the university decided to move it downtown to better connect it with the city’s social life. That decision gave the architects permission to come up with a visually daring design for the building’s urban context–with its dove-gray, textured terra-cotta panels and glass facade, the School of Music was designed to be a striking symbol for Iowa City. At the same time, using FEMA funding created a major constraint due to the rules of using disaster-relief funding. FEMA requires an open-bidding process for the projects constructed with its monies, and the contractor who offers the lowest price (and who is often the least skilled) for the job wins. Even if LMN designed the most visually and acoustically strong concept on paper, it wouldn’t matter if the execution was terrible.
So the architects decided to design for the most basic building techniques out there. You won’t find exotic finishes or rare materials at Voxman, nor will you find anything that requires specialized hand-tooling to make. You will, however, find techniques that have been used (and perfected) for decades.
For instance, the architects specified an extra-thick cast-in-place concrete structure since it’s affordable and common. Plus concrete has mass, which is an important acoustic insulator and one of the best defenses against sound transmission from the noisy street outside to the sounds generated throughout the building. To counteract the harshness of the exposed concrete structure, the architects designed felt “fins” that attach to the walls and ceiling in the communal lounges, lobby, and hallways. They also applied bright colors to certain details–like the elevator banks and doors–to enliven the space, and specified industrial materials throughout the building, like the perforated metal panels that comprise the railings and banisters along the six-story-tall atrium and staircase that links the floors, to achieve a balance between cost savings and aesthetics. When the sun shines through the perforations, it creates a handsome dappled shadow effect.
The acoustic reflector in the concert hall, one of the most complex pieces in the entire building, looks like a master artist sculpted it. But it was actually produced by a company that typically makes metal facades for gas stations and car dealerships. The designers called for a dull, ultra-matte finish so that it didn’t look like metal at all. The material is also quite thin, so the architects called for folded up edges to give it a thicker, more robust appearance.
Why did its appearance matter? Because of a phenomenon called psychoacoustics, which influences your perception of sound in a space. When musicians–and informed audience members–see certain materials in a space, it affects their perception of the sound. Wood for example, is associated with warm sounds. It was important that the reflector didn’t read like an industrial element since metal has a reputation for producing undesirable “tinny” acoustics. Even if a room made of metal produced the exact same acoustics as a room made of wood, the prejudice of metal’s sound quality might cause some to perceive it as inferior.
“This is a panel that’s normally used to make facades of buildings that are exposed to extreme weather,” Van Dyck says. “When we proposed making the signature element of a concert hall out of a facade panel, there was quite a bit of heartburn.”
Even the way the architects produced their design documents was novel. One of the most critical aspects of producing the building was making sure its components–like the acoustic reflector–could be made on an CNC machine by the fabricators. Typically, fabricators will redraw the architect’s design documents since the programs architects use don’t always speak the same language as the tools fabricators use. Not so with LMN’s team, which produced design documents that were frequently one in the same as the construction documents. When Crawford’s team created digital models for the architects, the exact same files could be sent to fabricators, which sped up the process and reduced human error. The only way the architects knew they would get FEMA and the university to sign off on their ambitious designs was because they had this digital model.
“It was incumbent on us to develop documents that are really like an Ikea instruction kit that would be easy for any fabricator to understand,” Van Dyck says.
As complicated and experimental as the Voxman School of Music was, the architects delivered the building to the university ahead of schedule and under budget–an anomaly in an industry usually plagued with construction delays and ballooning costs. The architects credit the streamlined design and construction process wrought by algorithms and digital models. But as pioneering and innovative as the process is, what matters most is what came out of it.
“We knew we could make the most stunning building in the world but if it didn’t sound good, it would be failure,” Van Dyck says. “Going to a concert and closing your eyes and hearing spaces do their job is sublime.”
Move over starchitects, algorithmic architecture is officially mainstream.
Design Architect: LMN Architects
Associate Architect: Neumann Monson Architects
Construction Management: Mortenson
Acoustic + AV Design: Jaffe Holden
Theater Planning: Fisher Dachs Associates
Lighting Design: Horton Lees Brogden
Structural Engineering: Magnusson Klemencic Associates
Mechanical, Electrical, Plumbing Engineering: Design Engineers
Energy Analysis: The Weidt Group
Civil Engineering: Shive-Hattery
Vertical Transportation: Lerch Bates
Life Safety/Code: T.A. Kinsman
Cost Estimating: Rider Levett Bucknall