making waves

Designing a chic, inner-city skyscraper holds dual responsibilities. Potential owners clamour for view corridors out to signature landmarks while the city is hopeful of a sculptural event in return.

The 82-storey Aqua tower with undulating balconies surrounding pond-like areas of glass more than fulfils both these requirements. Designed by Jeanne Gang, principal of Studio Gang Architects, and driven by Jim Loewenberg of the Magellan Development Group, the Chicago high-rise and podium comprises a hotel, apartments, condominiums, parking and offices. The tower has a huge 176,515m² floor area and is one of the tallest buildings in the world created by a female-led architecture firm.

Gang designed Aqua's most distinctive features to reach out beyond the core structure calibrating the depth and curve of each balcony to optimise vistas to Lake Michigan to the east, Millennium Park to the south and the Chicago River to the north.

Each balcony was also uniquely designed to optimise solar shading and passive heat control for each apartment or condominium all part of the contemporary tower's LEED-seeking agenda.

Aqua was shaped by an organic, site-specific design process, says Jeanne Gang.

"Rather than starting out with the goal of creating an icon, we let the climate and views shape the building, weaving it into its surroundings treating the building and environment as interconnected."

Maintaining the development's green focus, Magellan found a cost-effective way to create the curves for the concrete balconies, even though no two are the same.

The answer was simply a piece of steel that could be bent to a required radius for each pour, says Jim Loewenberg.

"When each balcony was finished, the band would snap back to straight and there were around six miles of edges to be formed on the project. To be able to re-use this material was important in a green building context."

Despite the exterior's sculpture-like appearance, the building has a cost-saving structure at heart. Gang wrapped the tower's rippling facade around a practical, pro forma rectilinear concrete frame.

The three-story podium's landscaped rooftop is another feature of the development. The second largest in Chicago at 7400m², this mitigates potential summer heat-island effect and provides amenities for the hotel, rented apartments and condominiums in the form of a swimming pool, running track and outdoor fireplaces.

However, it is the striking facade that is Aqua's principal claim to fame. At intervals along the almost kinetic balconies, ponds of windows ensure sufficient natural light penetrates the buildings. Glazing efficiency was another important factor in Magellan's quest for an LEED rating. Six different types of glass clear, tinted, reflective, spandrel and translucent were used in the tower, with placement determined by the orientation and function of the interior space. Fritted glass is also used on both sides of all glass exposed to the air to minimise bird strikes.

Aqua Tower is on track to achieve LEED Silver Certification. This includes the award of five out of five possible points in the field of Innovation and Design Process.

Story by: Trendsideas