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The Unvarnished Truth

Here's why materials that age naturally are (often) the best choice for interiors, and how you can incorporate them into your next project.

By Andrew Franz, AIA

Here's why materials that age naturally are (often) the best choice for interiors, and how you can incorporate them into your next project.

For years, pure durability has ruled the design kingdom. Interiors of all kinds have been covered from ceiling to floor with materials and products boasting of long life-cycles with little degradation of their original, like-new looks.

But as technological advancements in finish materials steadily marched forward, many designers forgot to ask if that was truly the most desirable goal. In many cases, the results are plastified, impermeable and highly polished surfaces that offer little warmth or connection to the natural world—something humans innately crave.

It can be summed up in a word, biophilia, which refers to the natural and instinctive bond between human beings and other living things, as identified by Edward O. Wilson in his book of the same name.

This isn’t merely love of nature; some of us prefer the city over the lakes and mountains. But a minimally treated wood surface? It has an allure that’s hard to explain. This attraction has been dissected in a more recent book by Wilson protégée Stephen R. Kellert, entitled Biophilic Design. Skip past the sections on biophilic urbanism and geomorphology to the chapter named “Biophilic Architecture and Neurological Nourishment.” There, we learn how a simple, natural surface serves a deeper need in all of us.

Or skip the intellectual rationales altogether. People love wood, plain and simple. Naturally beautiful, with a mysteriously real texture, wood is substantial and appeals to all five senses.

The secret of much successful interior architecture is to present untreated woods and other natural surfaces—cork, stone, metals, wool fabrics and more—to the occupant. The result appeals not only because the materials age well and often feel right for the occasion; just as we feel healthier in a room filled with natural daylight, we respond more positively to these living surfaces composed of natural materials, treated or coated minimally—or not at all.

natural potential
The trend of increased use of organic, lightly treated surfaces brings the designer full circle. Copper, once prized for its natural patina, can be treated with modern methods to retain its original color, but biophilia-sensitive designers prefer the look of naturally aged and weathered copper, which somehow nourishes the spirit more so than its coated counterpart.

Just as patrons prefer the unbleached napkins at their local café, they feel safer touching natural-looking wood and distressed surfaces like reclaimed barn boards. Instead of only super-new, super-polished surfaces, the new zeitgeist favors the rougher and more handmade—which, whether it’s actually true or not, can suggest a more sustainable approach.

To specify the look, designers should consider the use of catalyzed finishes, which are thin but effective coatings favored by many cabinetmakers. According to wood finishing expert Ron Bryze, catalyzed finishes can include types of lacquers, conversion varnishes, polyurethanes, polyesters and even some vinyl sealers. Made up of long molecular strands, the finishes are harder and more resistant to water and chemicals. Unlike shellacs or conventional lacquers, catalyzed finishes will not melt into the previous coat once dry; to get adhesion, the finisher has to sand between coats.PageBreak

The best thing about catalyzed finishes is how they reveal the look of the wood. Done right, the coats are almost invisible—except on the budget worksheet, where their price premium may stand out.

Yet, it’s a relatively small investment in occupant health and morale that can reap large economic rewards. A recent white paper from environmental consultant Terrapin Bright Green, “The Economics of Biophilia,” compiles volumes of research to arrive at some jaw-dropping conclusions:

  • About 10 percent of employee absenteeism can be directly attributed to architecture that has no connection to nature
  • Biophilic work environments in New York City could produce nearly $500 million in productivity value
  • Similar changes to retail environments in California could increase sales by $47 million
  • Connection to nature can reduce the length of the average hospital stay by up to 8.5 percent

But even before Terrapin released its paper, architects and designers were already moving in this direction, for reasons of sustainability, health, and realizing the full potential of the built space to support the occupant’s well-being and purpose.

the material world
Reclaimed wood, no longer just for antique enthusiasts, has become a major component of many commercial designs. The corporate headquarters for Clif Bar & Company in Portland, Ore., for example, are dominated by reclaimed lumber. The design by ZGF Architects’ Kathy Berg radically repurposed an old warehouse, filling the former industrial space with natural light and rich wood tones. Berg’s team also created shallow wells near heavy traffic areas filled with smooth stones and planters. The combination of wood, stone, plantings and light creates a space adept at “neural nourishment.”

For a new waterfront hospitality development in Upper Manhattan designed by our firm called La Marina, we employed a raw-looking wood rain screen mixing lightly colored and unfinished boards. The pre-weathered look complements the buildings’ Corten steel roofs and gutters, together recalling the maritime structures typical of the Hudson River and New York Harbor. Inside, exposed metals and subway tile are at home with a natural oil finish for the wood slab bar top. Along with low-VOC coatings and sealants, the interior palette reflects the wooded setting of the restaurant and café, with a natural vibe complementing the beachside location and resort-like amenities.

Even office towers are well-served by these ideas. For a two-story vaulted lobby in the recently completed Bank of America Tower at One Bryant Park in New York City, irregularly sized segments of Jerusalem limestone around the lobby core lay bare actual fossil content. Wide planks of bamboo finish the lobby ceiling, and the elevator bank walls are covered in stainless steel-framed leather tiles. Designed by Cook + Fox, the materials mix generates a highly tactile, biophilic response, as well as decent acoustics. PageBreak

Metal surfaces can also produce desirable biophilic benefits. When SWA Group, a landscape architecture firm in San Francisco, set about occupying an old warehouse, the interior solution included the rich texture and rust color of Corten steel panels to affect the landscape architecture principle of “bridging the interior and exterior.” Designers with Ojanen_Chiou Architects used the panels to create a wainscot-height surface floated several inches from the original walls, starting as wayfinding near the parking lot, continuing unbroken along the façade and into the entryway where it clads walls, partitions and a reception desk.

creating living surfaces
In all of these merit-worthy projects, the finishes are left uncoated or coated only lightly. This is especially true for those that will not have frequent direct contact with occupants. But even those surfaces that occupants touch or step on regularly can be allowed to show wear—confirmation that inhabitants are alive and busy.

Incorporating living surfaces into commercial projects can be surprisingly simple, and will certainly be rewarding for the client. Keep the following four rules in mind:

  1. Carefully consider the intended use of the space before selecting finish products. Certain living surfaces will hold up better under heavy use and traffic than others.
  2. Choose the lightest possible coating for surfaces that need to be finished. The material should show as much of its innate color, texture or grain as possible. Heavy varnishes, polishes and treatments will conceal or otherwise diminish the biophilic aspects of the surface.
  3. Plan for the surface to age naturally. While it may be desirable to protect, for instance, the color of wood from the bleaching effect of ultraviolet rays, generally it is preferable to allow wood to wear, metal to tarnish and form a patina, stone to change color with age, etc. These aspects of the materials are the very same aspects that make them “nourishing” to the building occupants: the connection to nature and natural cycles of life.
  4. Couple the living surfaces technique with an aggressive natural daylighting strategy whenever possible. Light itself is healthful, and the interplay of the light with the finish material amplifies the biophilic effects, with the sun’s movement creating a play of shadows among the interior elements.

Sunlight is valuable not only for creating this art installation-cum-sundial effect; it also connects occupants and visitors to the natural, daily cycle of the sun. It’s a reminder that time is passing, which in biophilic terms is a good thing. Interior surfaces and finishes can do the same, too, if we allow them to age naturally.

By combining only a few materials—or by selecting many and varied living surfaces—we can enrich our surroundings in ways both subtle and aggressive. In all events, it will bring out our most natural appreciation.


Andrew Franz, AIA is the principal of Andrew Franz Architect, a full-service architecture, planning and design firm based in New York City. Recent projects by the firm include La Marina, a waterfront hospitality development in Upper Manhattan, as well as arts and performance venues and facilities for non-profits and foundations including Film Forum, Classic Stage Company, Century Foundation and the Mellon Foundation. Experienced in interiors and original furnishing design, Franz creates original expressions combining a classic aesthetic with a modern sensibility.