The Council on Tall Buildings and Urban Habitat (CTBUH), a leading international organization in the field of tall buildings and urban sustainability, honored the new U.S. Embassy in London as a 2020 Award of Excellence Winner in the Best Tall Building Under 100 Meters category.
Recognized for its exceptional environmental leadership and energy-efficient design, the embassy features an outer envelope of about 399 single-layer ethylene tetrafluoroethylene (ETFE) facade sails, which were designed, fabricated and installed by Birdair Inc. of Taiyo Group. The design concept was done in the U.S. with architects from Kieran Timberlake and project designers from Arup.
The embassy’s form is that of a transparent crystalline cube set atop a monumental colonnade, according to information from the architectural firm. The high-performance facade is made of laminated glazing and the outer envelope of ETFE, a transparent film shaped to minimize solar gain and glare, affording generous natural light throughout the interior and access to the site’s striking views. The tonality of the envelope shifts with the weather and time of day.
Birdair installed steel beams (57 carbon steel “headmounts”) at roof level, to which a hanging 180-ton aluminium skeleton was suspended, horizontally braced at intermediate levels. The skeleton has an articulation at every joint, and the ETFE panels were attached to the skeleton, resulting in an hourglass shape.
Constructed by B.L. Harbert International, the embassy building incorporates multiple energy conservation strategies, including daylight-responsive lighting and shade controls, passive and active chilled beams, efficient mechanical systems and combined heat and power generation. Renewable energy is harnessed through photovoltaic technology and ground source heat pumps, which use energy from the earth to heat and cool the building. Work was completed on the building in 2017.