The Union Square development area showing the site of the ICC tower and some of the finished buildings.
Map of the layout of the Union Square site.
Artist's representation of the new tower design.
Artist's representation of the Union Square site looking over to Victoria Harbour.

The International Commerce Centre (ICC) in Kowloon, Hong Kong, is a new office and residential building developed on the Union Square site. Formerly known as Union Square 7, the tower was jointly developed by Mass Transit Railway (MTR) Corporation and Sun Hung Kai Properties. It is currently the tallest building in Hong Kong.

The tower is located on Nga Cheung Road and Austin Road West, at the southern tip of the West Kowloon reclamation area overlooking Victoria Harbour in Hong Kong. The tower was the final stage (Phase 7) of the Kowloon Station Development, known since 2001 as the Union Square complex.

Construction details of the International Commerce Centre

Construction was started in 2002 following a number of design changes to the originally planned ‘world’s tallest’ tower by the architects Kohn Pederson and Fox of New York, US, in September 2001. The old design had a 100m pyramidal top that included a transparent atrium, which would have raised the structure’s height to 580m. The construction was completed in 2010.

The developer took the decision to re-design the tower mainly due to new height restrictions imposed by the planning department in the areas around Victoria Harbour. These restrictions are in place to keep buildings from rising higher than nearby mountains.

The new design is a square 484m tower with 118 floors and 270,000m² of office space, retail areas, serviced apartments, hotel space and car parking facilities.

Design of the building

The building has been designed with tapered re-entrant nooks and slanted arcs at the base, which optimise the structural performance. These curves are spread outwards and create canopies on three sides of the structure. An atrium on the north side provides space for retail and rail station functions.

Mass Transit Railway – developers and finance

The tower was developed by the MTR Corporation (as the customer), Sun Hung Kai Properties (SHKP), Hang Lung Group, Wharf Holdings and Wing Tai Group.

The 270m-high Cullinan residential complex comprising two smaller 68-storey towers, the Cullinan north tower and the Cullinan south tower, was completed in 2009. The 262,185m² tower was known as the Union Square Phase 6 during construction.

"A seven-star hotel, operated by Ritz-Carlton, is located near the top portion of the tower."

The tender for developing the last two stages (Phases 6 and 7) of the ‘Kowloon Station Development’ at Union Square was awarded to SHKP in October 2000. The project was estimated to be worth HK$29bn ($3.85bn). One major financial term is that SHKP will have to give rental and management rights of 78% of the 82,750m² shopping mall to the MTR.

The land for the project costs HK$7.4bn. Kowloon Station, which is one of the six subway stations of the Tung Chung Line and Airport Express Line, is situated in the podium beneath the MTR tower. This tower forms a gateway for Victoria Harbour with the two International Finance Centres (2IFC) at the opposite side of the harbour.

Facilities at the ICC

The Elements Mall with a space of one million square feet, located in the basement of ICC, provides world-class retail and dining experience to the visitors of ICC. Designed by Benoy, the mall opened in 2007. It embodies the five elements of nature- metal, fire, water, wood and earth.

The ICC houses some of the world’s finest hotels, including the Ritz-Carlton, W Hong Kong and the Harbour View Place.

Three restaurants, namely Dragon Seal Restaurant & Bar, Inakaya and Tenko RyuGin, located on the 101st floor of the ICC are known as the Sky Dining 101.

The sky100 Observation deck located on the 100th floor offers a 360° view of the surrounding area. The ICC also has a fitness centre on 20th floor. The car parking has a total of 1,700 spaces, 500 of which are reserved for the ICC tenants.

Sustainable features

The building has a smart cooling system that monitors and analyses energy consumption during day, night and different seasons, as well as makes energy-saving adjustments accordingly.

The elevators are accessed through a passenger smartcard system, which assigns elevators to a group of people heading to the same destination. Water is harvested from the air-conditioning system and is utilised for cooling towers and sanitation purposes.

ICC Contractors

The design architect for the project was Kohn Pederson and Fox Associates; the construction architect was Wong and Ouyang (HK). The construction was carried out by Sanfield Building Contractors and structural engineering by Maunsell Group and Ove Arup and Partners Hong Kong.

The mechanical, electrical and plumbing engineering was carried out by J Roger Preston. Geotechnical engineering was by Ove Arup and Partners Hong Kong, Bachy Soletanche Group and Intrafor Asia.

"Injecting the cement grout at high-pressure helped in increasing the friction between the soil and barrettes."

The company responsible for the foundations of the building was Backy Soletanche Group. The wind surveyor was Rowan Williams Davies and Irwin. The façade of the building was constructed by Arup Façade division.


Due its location in a major fault zone with unfavourable geological conditions, the common end-bearing piling system as foundation was not suitable for ICC. There is an excessive depth and irregular grading of the rock.

After a lot of research and study on different foundation systems, the engineers settled with shaft grouted friction barrette pile foundation system for the structure.

Injecting the cement grout at high-pressure helped in increasing the friction between the soil and barrettes. By this process, the pressure while injecting the grout condensed the soil, which was loosened during the excavation. Four working barrettes and five trial piles of 4,000t each were constructed to test the process before actual works began.

ICC is the first private development in Hong Kong to adopt the shaft-grouted friction barrette pile foundation system.

ICC Engineering

The façade for the building comprises triple-glazed, glass curtain wall panels and lacquered aluminium panels. The building is of a traditional construction with steel and site cast reinforced concrete framework / columns, along with a site cast reinforced concrete core section, housing services and elevator shafts. The floor sections include a steel deck with concrete overlay.