Light as Air

May 1, 2008

Translucent, visually floating architecture uses ample daylight, windows, screen enclosures, and a ceiling grid of white LEDs.

By Craig DiLouie

Sub-article: Analysis: Are LEDs Ready for Prime Time?

Starting in 1189, when Kaiser Friedrich Barbarossa granted the Port of Hamburg the status of a customs-free zone, the city has served as Central Europe's main port and home to a strong bourgeoise. Today, in fact, it ranks as Germany's largest port and Europe's second-largest container port. The voice of Hamburg's business community is its Chamber of Commerce, which provides services and representation to its 107,000 member companies. Since 1814, the chamber's home has been the Börsenhalle, a classic historic stock exchange building.

The chamber wanted an addition to accommodate amenities such as conference rooms and lounges and, in 2003, held a design competition challenging architects to propose concepts for a new three-story addition inside the building's main hall. The project was named Haus im Haus, or "house inside a house." The addition would have to reflect the historic character of the building yet be contemporary.

Behnisch & Partner proposed a somewhat different direction, earning the firm first prize and a contract to its affiliate firm Behnisch Architekten to develop the concept further and ultimately realize it.

"We elected to use a smaller footprint, leaving more of the integrity of the Börsenhalle intact, and build higher vertically," says Martin Haas, partner with Stuttgart-based Behnisch Architekten. The concept called for a 15,000-square-foot, five-story structure rising to a greater height than the original three-story plan, exploiting the main hall's height while preserving its generous nature.

The top floors include exhibition spaces displaying remarkable works from the chamber's economics library, the oldest of its kind in the world. (larger image) PHOTO: HANS JÜRGEN LANDES

"While respecting the particular requirements for this historic structure, the new structure within unfolds in layers and planes made of different materials," he adds. "The lightness and seemingly immaterial appearance of the structure contrast with the solid, massive walls of the historic hall. The structure is organized in response to functional requirements and a variety of fascinating spatial solutions emerge both within the structure and in relation to the existing building."

The former trading hall has historical arched windows that fill the space with generous amounts of daylight. (larger image)  PHOTO: HANS JÜRGEN LANDES

Steel and Glass
Raised from the ground on steel beams, Haus im Haus is composed largely of steel and glass. The structure accommodates working space for individuals setting up new businesses, meeting rooms for chamber members, a social club, open and private dining spaces, and an exhibition space displaying remarkable works from the chamber's economics library, the oldest of its kind in the world.

The top floors have a private character, with much of the space dedicated to the presentation of valuable old books. In keeping with the balance of history and modernity, traditional furnishings, such as tufted sofas and crystal chandeliers, are presented in a contemporary context.

A bridge on the second level connects the new structure with the Alberta-Schäfer-Saal of the historical hall, serving as an extension for receptions, exhibition openings, and other events. The roof terrace, reached via a small footbridge, provides stunning views of Hamburg's City Hall and the roofs of the Hanse town through a band of historical arched windows.

The ceiling of Haus im Haus consists entirely of custom LED panels connected to a control system, providing general and task illumination and a range of dynamic lighting effects. (larger image)  PHOTO: HANS JÜRGEN LANDES

LEDs and Daylight
Behnisch Architekten envisioned Haus im Haus as a visually floating, translucent, luminous structure. Daylight would be the primary light source, supplemented by electric lighting that would be controllable for maximum flexibility, highly efficient for maximum sustainability, and integral to the architecture.

"To consider artificial lighting not as a mere necessity but as a means of creating the impression of a translucent, floating structure represented a completely new departure in the design and definition of interior lighting," says Haas.

While the lower portion of the former trading hall has a series of archways leading to offices, the higher elevation has two levels of historical arched windows that fill the hall—and Haus im Haus—with generous amounts of daylight. Windows line all four sides of the structure and aluminum screens form partial enclosures on all sides, giving Haus im Haus a transparent, reflective character. Inside, a grid pattern of glass panels serves as the floor, permitting the flow of light throughout while also creating a translucent physical structure. "During the day, the screens capture the light, mimicking the various hues produced by sunshine and other weather patterns," says Haas.

The screens also reflect playful highlights from the interior's electric sources that consist entirely of LEDs. The ceiling, in fact, consists entirely of 3-foot by 3-foot white-light LED panels, designed by the architects in collaboration with manufacturer Nimbus, that provide supplementary lighting during the day and primary lighting at night. A grid of 400 LED light points is mounted on each panel, the LEDs set into a 10-millimeter Perspex sheet into which 400 conical countersinks had been made.

"By thus embedding the light modules in the Perspex sheet, the latter itself functions as a soft, dazzle-free light source, without completely foregoing its transparency," Haas explains. The countersinks limit glare by limiting the emission angle to 90 degrees; light distributed in a horizontal direction is visually more comfortable. "A sense of height and open perspectives is thus retained," he says.

The floors are also lighted from below either by broad grid formations of light modules or other, smaller clusters that function as accents.

Above: Haus im Haus accommodates working space for individuals setting up new businesses, meeting rooms for chamber members, a social club, and open and private dining spaces. (larger image) PHOTO: ROLAND HALBE Below: A bridge on the second level connects Haus im Haus with the historical hall, serving as an extension for receptions, exhibition openings, and other events. (larger image)  PHOTO: HANS JÜRGEN LANDES

Lighting can be adjusted as needed via an advanced control system for practical or aesthetic purposes. For example, it can be set to dim up and down for functional use and aesthetic appearance. Touchscreen control enables operators to program and recall dynamic light sequences, such as calming light waves that ripple almost imperceptibly across the ceiling, slowly drifting "clouds" of light, or single shooting stars that flare and fade.

"The LED modules can flood a selected area with sufficient light for work procedures or, on a dim setting, simply mark access routes," says Haas. "The LEDs are computer-programmed to mimic the daylighting program. In the evening, this provides the illusory effect of being in the daytime. Such adjustable lighting, employed only when and as required, represents a hugely cost-effective and environmentally friendly investment."

Craig DiLouie ([email protected]), a lighting industry journalist, analyst, and marketing consultant, is principal of ZING Communications.

Project | Haus im Haus

Owner | Hamburg Chamber of Commerce

Location | Hamburg, Germany

Architect | Behnisch Architekten (Stefan Behnisch, David Cook, Martin Haas)

Interior designer | Behnisch Architekten

Light planning (LED lighting system) | Nimbus Design

Lighting | Ulrike Brandi Licht

M/E/P engineer | TPlan

Photography | Roland Halbe; Hans Jürgen Landes

Lighting manufacturers | Nimbus, Lux Lichttechnik, Erco, Baumann Metallbau GmbH

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