Optimize, Optimize, Optimize: Museum Conservation in the LEED Era

by Lindsey Westbrook

A conservator wearing a mask and touching up a sculpture

Photo: Katherine Du Tiel

Of all the behind-the-scenes museum jobs, the one many find most alluring is conservator. Sounds glamorous, right? Repairing Rembrandt’s Night Watch after it was slashed by a madman. Restoring Michelangelo’s Sistine Chapel ceiling to its original glory. And who can forget the art-historical heroics of the Monuments Men? In reality, the job can be stressful and requires the steeliest of temperaments, as it involves close personal contact with, and responsibility for, priceless works of art.

Traditionally, the field of conservation has been dedicated to arresting change in the interest of preserving artworks. And, being a careful lot, conservators tend to resist propositions that risk compromising the welfare of the art in their care. This is why, when the Smithsonian announced in the 1990s that it was taking a more fluid, seasonally based approach to temperature and humidity controls in its galleries—allowing for colder and drier conditions in the winter and warmer and more humid ones in the summer—many in the field were shocked. Yet the obvious cost savings made many a museum director take note (and consider adopting) what have come to be called “seasonal set points.”

World War II Sets the Standards

Since the middle of the twentieth century, says Michelle Barger, SFMOMA’s head of conservation, the accepted standard among conservators has been to keep galleries at 50 percent humidity, plus or minus 5 percent, and the temperature at 70 degrees Fahrenheit, plus or minus 2.

“That’s still the standard. But do you know why?” she asks with a smile. “Turns out it started in World War II, when they moved important artworks out of London and hid them in slate caves in Wales to protect them from looting and bombing. When they took them out after four or five years, they said, hey, these things are in pretty good shape!"

Black and white photograph of wrapped artworks lined up in a cavern

Photo: Cpl. Donald R. Ornitz

Prior to that, museums in London—and most everywhere—weren’t climate controlled. And conservators were repeatedly fixing flaking paint because fluctuating humidity was making the canvases expand and contract. Suddenly the field of conservation science was born, and it universally adopted the Wales cave conditions as optimal for galleries. And with that decision came a hefty line item in the budget for energy—especially in cities like Chicago or Milwaukee or Boston, which have extreme temperature and humidity swings over the course of the year.

LEED Demands New Approaches

When SFMOMA first learned that it would be expanding, it was a given that the new building must meet LEED gold criteria. This is a requirement for all new construction in San Francisco; it means that out of approximately 100 possible points in categories related to materials, energy usage, water efficiency, and so on, the building must score 60 or better. With San Francisco’s moderate climate, achieving this isn’t ordinarily too difficult. But for a museum, temperature and humidity control is a major priority—one that can make or break your ability to receive artwork loans from other museums, for instance. And it not only costs a bundle, but it takes a bundle of energy to make it happen, which can compromise your LEED score.

After Snøhetta was announced as the architect for the new building, the museum brought in Atelier Ten, an environmental design firm, as a sustainability consultant to work closely with the architects and the museum. Their collective job: to devise engineering strategies that would make the new building as efficient as possible across its mechanical, lighting, water, and other systems to make the LEED grade.

The front of the SFMOMA building

Photo: © Henrik Kam

Within this context, our conservators were asked to revisit the prevailing temperature and humidity standards. As it turned out, the larger field of conservation was doing the same thing; several seminal and somewhat contentious conferences had taken place just in the preceding few years. With consensus nowhere on the horizon, SFMOMA initiated our own Sustainability Roundtable in order to research a solution that would work for our institution and timeline.

Whiteboard showing an undulating graph

Internal stakeholders from conservation, registration, and engineering departments were invited, as well as representatives from Atelier Ten, Snøhetta, and Taylor Engineering (the firm providing mechanical and plumbing engineering). Also present were external experts who had been studying the issue for years, including staff from the Getty, the MFA Boston, and the Indianapolis Museum of Art. Local museums involved in building projects were invited as well, including the Anderson Collection at Stanford. At the end of the session, the group arrived at seasonal set points that would help reach the LEED target while still providing a safe climate for the needs of the collections.

An undulating graph illustrating set points of humidity based on the time of year.

Optimize, Optimize, Optimize

“We realized from the outset that minimizing the building’s energy consumption was key for LEED,” says Shruti Kasarekar of Atelier Ten, “and it involved customizing every aspect of the design of the structure and its systems. Optimize, optimize, optimize became the mantra. Where exactly are the windows? Can we extract a tiny bit more efficiency from the air conditioners? And so on. We ran through a long, iterative process of testing approaches, and combinations of approaches, to arrive at the best possible configuration of efficiency measures.”

Lara Kaufman (of Snøhetta) and Lotte Kaefer (of EHDD, the architecture firm partnering with Snøhetta) stress that while LEED compliance was a requirement, it was really just the beginning. Maximum sustainability was the true goal, and optimizing for that was the fun part. “We’ve gone above and beyond in so many areas vis-à-vis LEED,” says Kaefer.

“We had the climate in San Francisco working for us,” says Kaufman, “as well as the fact that, for conservation reasons, the galleries don’t have lots of windows, so you don’t have much heat loss there. Although we soon realized that retaining heat wasn’t going to be a problem; rather, shedding it was, since all those visitors are like little radiators, generating BTUs and humidity. So the mechanical system is set up to shed those loads most of the year.”

Visitors in a gallery look at large-format photography

Rendering by Steelblue

“Then, once we had optimized the heck out of the HVAC system,” says Kasarekar, “the next biggest piece to tackle was the lighting. Galleries require specialty lighting, but we needed to manage the energy consumption in order to reach the overall building goals.” Arup, the lighting engineers who collaborated with Snøhetta’s design team, came up with a “lighting energy budget” scheme that distributes the power draw across the building. Simply put, if the lights are brightened in one area, they must be dimmed in another. The controls are sophisticated, but they’re all managed from an iPad.

“Visitors may not realize that those curved ceilings on floors 4 and 5 are the result of a lot of computer modeling to optimize the throw of the lights within the space,” says Kaufman. “We built scale mockups so that the curators and crew could experiment with different types of track and fixture arrangements. In the final, multi-layered system, ambient lighting above coves (low energy load) allows the museum to use fewer track light fixtures (high load).”

An installation shot of the curved ceilings of the galleries

Photo: Henrik Kam

Contributing to the Field

Barger has been gratified to see SFMOMA fast-tracked into the larger conversation in the conservation community regarding the “cave” settings, thanks to San Francisco’s ambitious LEED targets. The results of the Sustainability Roundtable were presented at two of the most important museum professional conferences: the American Institute for Conservation (AIC) and the American Association of Museum Directors (AAMD).

“We’re definitely an ‘early adopter’ of the seasonal set points, and it’s been affirming to share our solution—and our process for getting there—with the field,” says Barger. “It’s really rewarding to contribute to momentum around this issue.”


Lindsey Westbrook

Lindsey Westbrook is a freelance editor and writer specializing in art, architecture, and design. Her clients include SFMOMA, Istanbul Modern, UC Press, Princeton Architectural Press, Kunsthalle Basel, the Museum of Contemporary Art Detroit, the Felix Gonzalez-Torres Foundation, and many others.

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