Council on Tall Buildings and Urban Habitat
 

Sowwah Square, Abu Dhabi
Featured February 2014
Sowwah Square was recognized as the winner of the "Best Tall Building Middle East & Africa" award in the 2013 CTBUH Awards Program.
Other Featured Tall Buildings
“This is a very powerful composition where sustainable features have been embedded from the design stage as part of the core functions within the complex.”
- Karen Weigert, Juror, Chicago Chief Sustainability Officer

Location
Abu Dhabi
Completion
2012
Height
Al Khatem, Al Maqam: 155 m (509 ft); Al Sarab, Al Sila: 131 m (430 ft)
Stories
Al Khatem, Al Maqam: 37;
Al Sarab, Al Sila: 31

Primary Use
Office

Owner/Developer
Mubadala Real Estate & Infrastructure
Design Architect
Goettsch Partners

Architect of Record
Serex International

Structural Engineer
Oger International (design); Serex International (engineer of record); Thornton Tomasetti (peer review)
MEP
Oger International (design); Environmental Systems Design, Inc. (peer review)
Contractor
Oger Abu Dhabi
Other Consultants
Hann Tucker Associates (acoustics);
WSP Group (fire); Martha Schwartz Partners, Ltd. (landscape); Integrated Environmental Solutions, Ltd. (LEED); One Lux Studio, LLC (lighting); MFD Security Ltd. (security); Jenkins & Huntington, Inc. (vertical transportation);  RWDI (wind)
Sowwah Square stands out as consciously sustainable and warmly inviting, yet a formally disciplined project in a region where achieving such aims have historically proven difficult. The interdependent elements work together such that the project functions as an integrated machine. From sun-tracking shading devices to elevated lobbies with views of cool roofs and the sweep of the harbor, little seems to have been left out of the calculations. That a building in this climate could support as much glass as it does is a testament to the possibilities of well-orchestrated design.

Its clear massing and organization helps to ensure that the design will not appear dated and will continue to support pedestrian activity, even as new sustainable technologies come into use. The elevation of the stock exchange on pedestals reinforces the importance of the commercial activity inside, while creating an enticing, shaded communal space beneath, lending a calming tone to the monumental surroundings. The curving approaches at the waterside promenade promise to soften the edges of the angled towers, while clearly pointing the way to the center of activity.


Sowwah Square is a major new commercial development on Abu Dhabi’s Al Maryah Island. The city’s new urban framework plan, entitled Plan Abu Dhabi 2030, has designated the previously undeveloped island and the adjacent edges of Mina Zayed and Reem Island as the city’s new Central Business District. The project totals over 290,000 square meters of office space and features the iconic new headquarters building for the Abu Dhabi Securities Exchange, surrounded by four office towers, all overlooking the water. In addition, the project integrates two levels of retail and two parking structures. A generous landscaped plaza connects the four buildings and the exchange.
Figure 1. Overall view of complex at night
The stock exchange building at the center of the complex is an iconic, four-level facility. Glass-enclosed with a roof the size of a football field, the building rises 27 meters above a 49-meter-diameter water feature on massive stone piers. The four granite piers house the stairs, mechanical risers, and service elements for the exchange. The four office towers frame the stock exchange building. The first full office floor of each building starts 34 meters above the ground level, providing a transparent, open lobby and elevating the views from tenant floors.
Beneath the plaza, a two-story retail podium weaves through the development, providing 23,220 square meters of upscale shopping along the waterfront. At the north and south boundaries of the site, two parking structures, partially submerged, serve the complex with more than 4,800 parking spaces.

Sowwah Square is the first mixed-use project in Abu Dhabi to be pre-certified LEED-CS Gold based on sustainable initiatives. However, the complex looks beyond the LEED certification process to emphasize a sustainable design approach throughout, integrating both active and passive sustainable design strategies.

The environmentally responsive enclosure system uses a mechanically ventilated cavity and a double-skin façade system over large portions of the office buildings. These elements mitigate the 40 ºF interior/exterior temperature differential and protect building occupants from the intense sandstorms and the constant corrosive mist of the neighboring Gulf coast.

The double-skin cavities run uninterrupted along the entire height of the four office towers, starting from the fourth floor and extending to the penthouse mechanical floors. Within these cavities, active solar shades continuously track and adjust for the sun angle to provide optimal shading to the building’s interior. The cavity is sealed to protect the gears from airborne particulates.
Figure 2. Office tower lobby
Active solar shading and glass selection keep the cavity from increasing the internal radiant temperature. To minimize the amount of solar energy penetrating the outer layer of the double-skin system, an outboard fin with a very high shading coefficient (76 percent) was selected. The remaining energy was then blocked from reaching the inner façade by the active shading; however, its presence contributed to an elevated air temperature within the double-skin cavity.

Figure 3. Complex plan
To alleviate the accelerated temperature and achieve the moderating air buffer, the warm cavity air needs to be flushed out using an air source cooler than the natural air temperature. The solution was to collect the exhaust air from the tower offices and, instead of allowing it to escape into the atmosphere, redirect it back down the double-skin cavities, where it is exhausted at the fourth-floor mechanical level. Sensors within the cavities modulate dampers at the top of the building, directing the air to the optimal zones of the cavity depending on the time of day and outdoor temperature. Additional dampers will allow filtered exterior air to enter directly into the cavity during economizing periods such as night and winter, when the outdoor air is cooler than the collected exhaust air.

Figure 4. Detail section through double-skin façade Figure 5. Diagram showing location of double-skin façades
Through these efforts, the design team expects the double-skin cavity to be an average temperature of 89 ºF (32 ºC) when the exterior temperature reaches 115 ºF (46 ºC). This condition will allow the high U-value of the insulated inner glazing to more easily block the air cavity’s radiating energy. Most importantly, calculations estimate that the double-skin system designed for Sowwah Square will generate savings of 7,200 kWh of electricity per day across all four towers and provide a more comfortable thermal environment near the perimeter wall, all while protecting itself from the harsh external elements.
Figure 6. Interconnecting plaza looking over the water
Related Links
CTBUH Skyscraper Center Profile:
Sowwah Square

Sowwah Square was recognized as the winner of the "Best Tall Building Middle East & Africa" Award in the 2013 CTBUH Awards Program.

Download Sowwah Square 2013 CTBUH Awards Book section
2013 CTBUH Awards Book
The CTBUH would like to thank Goettsch Partners for their assistance with this article.
Photography © Mubadala Real Estate & Infrastructure and Goettsch Partners