The metal screen that wraps around much of the new Science and Engineering Complex at Harvard University is a piece of advanced engineering in motionless action. Made of 14 000 panels of precisely formed and cut stainless steel, it appears to be a gigantic cheese grater. But the façade is actually a finely tuned device for controlling both the light and the heat that enters the building.
Modelled to block the heat of the summer sun and allow it in during the winter, the façade’s panels are an intricate but stationary control system that dramatically reduces the building’s heating and cooling requirements compared to a traditional HVAC system, bringing the complex’s carbon emissions down by an estimated 42%. The façade manipulates light by selectively reflecting the sun into the darker parts of the half-million-square-foot building, cutting down on its electricity costs.
“The idea was to do as low-tech of a building as possible,” says architect Stefan Behnisch, whose Boston- and Germany-based firm Behnisch Architekten designed the complex. Reducing the building’s heating, cooling, and lighting requirements is part of the way Behnisch and the university are hoping to address the large greenhouse-gas footprint of such a big complex. Buildings account for nearly three-quarters of electricity use in the US and even some supposedly high-performance buildings rely on energy-inefficient mechanical systems to keep them comfortable. Using a passive façade proved a much more environmentally sustainable approach. The goal is to keep the sun on the 200 hottest days completely out of the building”.
Set to open to students later this year, the USD1-billion Science and Engineering Complex is the first major element of Harvard’s campus expansion in Boston’s Allston neighbourhood, across the Charles River from its main campus in Cambridge. The complex was intended to stand as an emblem of the prestigious university’s cutting-edge science and engineering capabilities, and an opening act for the expansion.
The low-tech façade of the building, perhaps counterintuitively, is the smart solution for a place with such a high-tech purpose and sets the stage for the innovations the complex is likely to help foster. “It was expected that this first building would set the terms for the future campus development. So, it was not easy to develop,” Behnisch says.
Originally planned in the early 2000s as a laboratory building, the project hit a wall during the financial crisis. Once the dust settled, the project was reimagined as a more diverse building, housing labs, lecture halls, and classrooms to accommodate bioengineering, computer science, data science, electrical engineering, materials science, and mechanical engineering—many different types of spaces to pack in, even for a building complex this large. “It became a very complex program,” Behnisch says.
Intended to be one of the greenest buildings at the university, the project was designed to meet the LEED Platinum environmental standard and the Living Building Challenge health and wellness standard, which certifies that its building materials are free of common harmful chemicals such as asbestos and chlorofluorocarbons. The building also met the standards of Harvard’s own Healthier Building Academy, a partnership among faculty from the university’s Office for Sustainability and the schools of engineering, public health, and medicine.
“Quite a few of the materials we normally use especially here in Europe for fire protection or even wood materials, we couldn’t use because we couldn’t get the necessary environmental certifications from the companies. It was a laborious route,” Behnisch says. “The university was very ambitious. Only a few clients are willing to undertake this effort”.
Behnisch says it was important from the start that the project be a physical representation of the university’s scientific focus. The façade became the most visible way of putting those ideas into built form. Behnisch Architekten partnered with the environmental engineering and design firm Transsolar to develop the façade’s approach and refine its design. Shaped like punched-through picture frames, with elongated fins around their top edges to block or redirect the sun, the panels create a grid outside the building that, while not invisible, still allows people inside to see out.
Getting the façade’s 14 000 panels built was another challenge. “I always had the idea that it was not different from a car hood,” says Behnisch, suggesting that the rectangular-shaped panels could likely be stamped out of steel using a typical two-form press. But this approach was found to be less than ideal. “The two forms are usually grinding, so the metal can’t flow easily, it’s stretched, and you need more material to make it stable”.
Behnisch reached out to German fabricator Edelstahl-Mechanik to try a different approach, using a single form and high-pressure water to push the flat metal plates into shape and laser-cutting the fine details for each panel. “We were able to save about a third of the material,” Behnisch says.
The real savings will come over the life of the building, as the stationary façade passively blocks heat and allows in light. Along with the building’s other environmentally sustainable features, the façade will help it produce fewer carbon emissions than a comparably sized building.
The façade system builds on one used in another, smaller project, in Switzerland, but Behnisch says the Harvard example shows how effective the concept can be at reducing energy requirements on a large scale. He hopes to refine and replicate the concept on other projects going forward.
“When we look at the energy consumption of the building sector, we need to become more efficient. And the efficiency should be triggered by design, by intelligence, and not just throwing more mechanical elements in the building,” he says. “The high functionality is determined by an intelligent design. And I thought that is what this school of engineering is all about”.