We like to argue that structural forms should be tuned to their function. When this is done well, it brings an intrinsic elegance that adds to the aesthetic of a building. Arches, shells cables nets, tapered cantilevers are all examples of expressed structural systems.
This should not really be surprising. We are surrounded in nature with things like trees, spider webs and egg shells amongst others which for very good evolutionary reasons have forms that are highly tuned to their structural function. Our sense of “the way that things should look and be” is formed by our everyday experience and we generally feel more comfortable where the structural function of what we are looking at is evident in its form.
Fortunately, there is more to building design that structural performance, and fortunately not everything in nature is shaped by gravity forces…!
In a context of shrinking energy resources and climate change, the need to tightly control energy use has become a prominent design driver in the built environment. In environmental design, the drive for energy efficiency needs to be well balanced against comfort and well-being, in particular.
As structural expression has contributed to shaping buildings of the last century, environmental drivers such as solar shading, daylight, ventilation and envelope efficiency should contribute more to shaping today’s buildings, influencing their massing, their facades… and at a larger scale also influencing masterplanning.
We have been weaving some of these environmental drivers into the design of a number of canopy roofs and façade screens. This presentation on Environmental Expressionism includes a number of examples. For the design of the canopy roof on the new Santa-Maria del Pianto underground station in Naples we have considered shading, daylight and structural efficiency to drive the arrangement of the elements of a complex lattice structure. For the canopy roof of the Capodichino station, also in Naples, we have inserted twisted fabric sails into an efficient cable net roof structure, and tuned their geometry and arrangement for shading and daylight. On the Biomimetic Office project we have optimised the massing of the building for daylight and usable floor space. On the UCL New Student Centre in London and the Cabo Frio Convention Centre in Rio, we have proposed façade screens tuned to control solar gains, whilst not compromising daylight and views.
In design having a number of often conflicting design drivers is the rule rather than the exception. Advances in 3D parametric design and multi-objective optimisation have made it easier to effectively handle these multiple drivers and produce buildings better fitted to their use and their environment. And moreover… we have found that the optimal character that emerges from resolving the design tensions between multiple drivers often has a certain visual appeal, analogous to the visual appeal of natural systems that have adapted to meet varied and sometimes conflicting objectives through evolution.
Image courtesy of Exploration