Material is at the heart of the architectural imagination. We can talk about architecture through many lenses: as part of the urban fabric, as a social engine, as a formal exploration. But material is fundamental to the realization of ideas and intentions. It is the matter, stuff, and substance from which a thing is or can be made — something you can feel, see, and relate to. It is critical for bonding architecture to the human experience, to joining it to the surrounding setting, and for generating meaning and significance.

Our choices today span an enormous range from “old” materials — stone, brick, concrete, wood — which are relatively heavy and massive, to “new” materials — metals, glass, plastics — which are relatively light and transparent. Old materials convey stability, timelessness, nobility, and permanence, whereas new materials convey lightness, ephemerality, and mobility.

Architects around the world whose work is fundamentally inspired by material investigations abound in both spheres. Tod Williams Billie Tsien in New York, for example, is extraordinarily inventive with massive materials, working with concrete, brick, and stone in ways that create an architecture that is grounded, embedded in the earth, and aspiring to permanence. At the Barnes Foundation in Philadelphia, the firm responded to the challenge of rehousing an extraordinary personal art collection by creating “a gallery in a garden” with two long solid volumes for the education programs and the collection, framing an elevated light box for gatherings, events, and repose. The solid exteriors are clad in a woven pattern of limestone, which suggests the solidity and nobility of mass stone, reinterpreted in assemblies of metal-framed thin stone panels.

In our own work on the Design Building at the University of Massachusetts Amherst, we explored cross-laminated timber (CLT) construction — a modern version of the “old” material of heavy timber — as an optimal fit for the client and its context. The building program had as a primary goal the demonstration of sustainable environmental design. Research in engineered timber by the faculty at this rural campus made it a natural choice as a pedagogical opportunity. The glu-laminated columns and beams, CLT floor and roof slabs, and wood-and-steel zipper trusses for the atrium create a space of solidity, natural beauty, and warmth. Our work with contemporary mass timber extends and redefines traditional heavy timber, long used for barns, industrial sheds, and warehouses. The spaces, shaped by wood with its inherently sustainable origins, create a feeling of strong connection to the earth and to nature.

Lightweight materials have been the subject of intense investigation since the mid-20th century. In the past two decades, that investigation has accelerated. The Museum of Modern Art’s 1995–96 Light Construction exhibition and Harvard’s 2002 Immaterial/Ultramaterial exhibition both attest to the strong interest in expanding the limits of lightweight materials and their fabrication. Fumihiko Maki in Tokyo is an extraordinary innovator of light construction, exploring the potential of metal siding and screening. His many inventions with new profiled metal panels, tubular screens, and layered assemblies span the cultural sensibilities of Japan and the West. At the MIT Media Lab in Cambridge, Massachusetts, a collage of metal screens, crisp panels, and glass on the exterior create a delicately adjusted scale for this very large building in a campus context. On the interior, transparency and translucency from the central atrium to the outer walls provide an environment suffused with light. As associated architects on the project, we were fortunate to participate in developing the subtlety and refinement of each material and its assembly.

Our own work in older urban and campus contexts has prompted us to explore the expressive potential of light metals — copper, stainless steel, and aluminum siding, perforated screening, and panels — in structures as diverse as museums, university buildings, and energy plants. At the Museum of Medical History and Innovation for Massachusetts General Hospital in Boston (a front door to the hospital complex at the foot of Beacon Hill), we chose to clad the building in copper siding. Facing brick townhouses and the nearby State House, the copper material responds in color to its context while providing a new texture, reflectivity, and lightness to the building. The long three-story street façade is clad in standing and flat-seam copper panels and copper-fritted glass, creating a strong presence despite its modest size. We have discovered that metal materials introduce a delicacy and refinement of scale, and make insertion of new structures into a dense context more graceful and distinctive.

For me, the search for the right material to express a building’s human purpose and sense of place is paramount. The choice of material is a question of fit. Each project demands an exploration of material research, selection, and detailing to respond to context, to meet sustainable goals, and to evoke a compelling emotional impact.

My colleague Jorge Silvetti, a professor at the Harvard Graduate School of Design, put it well in his introduction to the Immaterial/Ultramaterial exhibition catalog: “Materi-ality is more than a technical property of buildings: it is a precondition that promotes ideas, creativity, and pleasure in architecture, and it guides us to the loftiest aspirations of theory.” To say it even more simply: Material makes an idea come to life.