A native of California, Gregor Horstmeyer is an enthusiast of performance-based seismic design, in addition to glass, timber and concrete design. Growing up working in a glass blowing studio, he eventually combined his interest in glass with studies in engineering by writing a final year thesis on hyperbolic glass shell structures at the Form Finding Lab . Since joining Eckersley O’Callaghan in 2011, Horstmeyer has worked on projects of all scales in numerous parts of the world.
Sigrid Adriaenssens: Where does your fascination for glass stem from?
Gregor Hortsmeyer: I attended a public high school that had an incredible visual arts department. The dedicated teachers there worked tirelessly on behalf of the students and the program to find funding for study in various media. Specifically, David Camner was awarded grants to promote teaching the fiery arts: ceramics, bronze casting, and glass blowing. Interested in art, I signed up for the program as soon as I entered high school.
(In the glass studio; Paly Glass)
As a young individual with an affinity for science, time spent in the glass studio became the tactile and physical counterpart to the phenomena I studied in my chemistry and physics classes. Working with glass connected me to processes in action: phase changes, centripetal force, viscosity, thermodynamics, fracture mechanics, and thermal strain. All are simultaneously at play, and many of the properties inform one-another. What on a whiteboard is a complex system to describe and understand, is in the art studio an active experiment. I spent those four high school years arriving at studio before sun rise and staying after hours to experiment with glass as much as I could.
What is the most interesting property of glass and how can you exploit it in design?
Glass is a non-crystalline solid that is made of disordered SiO2 molecules held together by strong and stable atomic bonds. One consequence of this atomic arrangement is that the electrons inside glass are not excited when bombarded with photons across a range of energy levels, namely the energy levels corresponding to the visible light spectrum. As a result, the material is transparent – non-reactive to visible light, allowing it to pass through largely unabsorbed and unaltered.
To exploit the transparency of glass, we try to better understand the physical characteristics of the material so that we can create structural elements and systems such as glass walls and glass roofs.
What is your most daring structural glass project? What was the challenge and how did you solve it?
A recently completed tower in Salt Lake City has a large glass apron at the entry level that is designed to offer maximum transparency. Additionally, the structural glass facade is designed to tolerate extreme building movements.
Kinematic Façade Global; EOC
The slender building core that supports all 24 hanging stories is set back from the perimeter to allow for an expansive and column-free thirty-five-foot-tall lobby entrance. This design results in significant building movements during seismic events. While all hanging floor plates above the ground move together uniformly, the lowest hung floor (Level 2) interfaces with the stationary base-supported entry façade. This presented a challenge.
The critical design challenge was to dissect and understand how the building moves during wind storms and seismic events. A study of deflections, rotations, supports, and rigidity was conducted to define a realistic solution to enclose the building with glass and accommodate the building displacements without developing undesired forces in the structural glass assemblies.
Kinetic Façade Hinge; EOC
To address these challenges and meet the design intent of a transparent all-glass facade, a kinematic hinge system was developed to accommodate the building vertical movements. Precision linear slide bearings were used to absorb the building’s lateral drifts which allowed us to avoid an opaque movement joint and ultimately create a facade that provides an incredible view into and out of the building.
What is your advice to young engineering students wanting to pursue a career in innovative and creative structural design?
As engineers, we are being asked to provide solutions to problems. We do not search for a singular scientific answer, but instead consider the constraints and offer one of often many possible solutions.
These possible solutions might be easy or difficult, simple or complex, cheap or expensive. It is the engineer’s job to determine the best solution given the project’s constraints.
Always be willing to consider creative solutions; don’t fall victim to the “it hasn’t been done, it can’t be done” mindset.
I believe that this creative approach should be an office philosophy. The engineering team should look beyond the obvious, most pragmatic solution. To be able to deliberate these alternative solutions you need to be surrounded by people with experience who you can look to for guidance – engineers who will challenge your assumptions. This mentality for solving problems should be fostered from the beginning of a career and I suggest young engineers to look for design offices where the Principals are actively involved in the design process themselves. In such a setting, a young engineer can gain confidence and experience in approaching problems with an open and creative mind.
What question do you never get asked and would like to be asked? What would be the answer?
It is not so much “what” I am asked but rather “when” I am asked. I think we, as engineers, should be engaged in answering questions much earlier in the design process. We need to understand the constraints and goals of a project prior to design conception. In that way, we can use our knowledge of structures and materials to inform the design right from the beginning. A great example of this is a staircase we designed in Uruguay.
We sat down in a meeting with a fabricator and he pulled out a piece of scrap paper that he had been given by the architect in Uruguay. The paper had a single line spiral drawn in the middle, and a vertical line on one side of the spiral. He clarified that this drawing was the design intent – a spiral staircase cantilevering on the side of a building. Then he left.
Being engaged with a design so infant, we were able to examine the fundamental behavior of the staircase and let that inform the design and material pallet. The final design impressed both the fabricator and architect.