Unilever wanted an open, airy interior; Behnisch was aiming to maximize passive solar design elements, heating and cooling and lighting that interior with as much natural sunlight as possible. The typical way to meet Unilever's goal without creating a blinding overheated space would be to use heavily glazed glass, which blocks out solar heat (and is thus inefficient in winter); the typical alternative would be a pricey double-layered façade, with an exterior skin that trapped and routed solar heat and an interior layer to block out the light.
Behnisch, though, came up with its own innovative approach, a two-layered skin for the building that combines the very old and very new, as sustainable design so often does. The very old: "operable windows" (aka windows you can open and close from inside to control the temperature) and Venetian blinds. The trouble with the blinds, though, is that they couldn't handle the high winds of Hamburg's docks, which brings us to the very new solution: the semi-transparent foil wrapper that gives Unilever Haus its distinct look, a high-tech material called ethylene tetrafluoroethylene (ETFE) that lets through all the sun the building needs while shielding the blinds from the wind. In pursuit of a bright, open interior, then, Unilever found itself with a groundbreaking, hyper-efficient new approach to passive solar design.
As for those interiors, they are stunning on many fronts. Here's the soaring main atrium around which the whole building is organized:
This is the sort of inviting, connecting central space Unilever had asked for. It's also the core of the first office building on the planet to be entirely lit by hyper-efficient LED lighting. Not that it needs much artificial light: that big, overhanging hoop is a solar reflector, designed to bring sunlight to every nook and cranny of the atrium.
The whole building is also naturally ventilated and green-roofed, which together with the passive solar elements and LED lights and reflectors have reduced the overall energy requirement to 70 percent below the German average. Every building material was chosen with the best of environmental and human health in mind — not just to be kind to the planet and its people, but also to improve productivity and reduce sick days (which have plummeted among Unilever's staff since they moved in).
For Unilever, all of this was first and foremost a question of profitability: employees who could come to work more often and interact more efficiently while they were there would be good for the company's bottom line. Hochtief, the building's developer, simply presented Behnisch with a budget and a design brief to Unilever's pragmatic specs. It was Behnisch that filtered these goals through a lens of sustainability, sacrificing high-end amenities (expensive fittings and trim, grandiose entryways and office spaces) in favor of a hyper-efficient and ultra-welcoming physical space.
"I consider it not being worth it to talk about an office in terms of function," Behnisch partner Martin Haas told me. "Let's talk about living space. Let's consider well-being as much as possible."
In particular, the Behnisch folks focused on the idea of lingering, creating spaces that workers would naturally choose to hang out and interact and trade ideas in. "The aim in the building," Haas said, "was to create a 'not an office' building. To develop public space, a space to meet."
This sounds like run-of-the-mill management buzzword bingo, but at Unilever Haus, there's evidence of the real thing everywhere:
The scene above wasn't staged. The photo was taken late afternoon on a rainy spring weekday, the kind of grey day where you're inclined to spend your last hour or so at work daydreaming or surfing the net. But there are Unilever's employees, lingering in the meeting spaces Behnisch designed.
Behnisch's Martin Haas told me they had begun from the idea that people spend as many of their waking hours in their office building as they do at home, so the place needed to be not a work space but a living space for working in, "a little village" with many different kinds of "spatial experiences" for all the different moods of the working day.
Somewhere in all of this talk, you'll find the idea of sustainability. To create a great environment for working in, you have to make the air quality superlative, give it lots of natural light, make it comfortable and efficient, place it in a vibrant community where there's lots to do before and after work and on lunch hours, make it easy to get to and from. The foundations of all of this are sustainable foundations. Sometimes, though, they're no more visible than a building's framework is as you ponder its striking foil-wrapped façade. To get to exemplary sustainability, in other words, you can start with something as simple as making an office space work better.
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