The Council on Tall Buildings and Urban Habitat (CTBUH) recently announced that Hourglass has received an ‘Award of Excellence’. This automatically nominates the building for a CTBUH Award in the category of ‘Best Tall Building under 100 meters’ which will be presented during the 2021 Tall + Urban Innovation Conference. This year, the convention will be held virtually from 18 – 21 May. A CTBUH Award recognizes exceptional contributions from architects, project developers and constructors to the advancement of tall buildings, the urban environment and sustainable building practices at the highest and broadest level.

key position
Hourglass, designed by Dam & Partners Architecten for Maarsen Groep en Zadelhoff, was purchased by Bouwinvest in 2016. The building that was completed in the summer of 2020, is located at a prominent spot on the Zuidas: at the northeast corner of the Kenniskwartier (‘Knowledge Quarter’), adjacent to the future Station Zuid train station and the Zuidasdok. In line with its key position, Hourglass has a multifunctional character. The program includes 22.000 m2 of office space, 115 long-stay hotel apartments, a public restaurant and commercial facilities on the ground floor.
Because of the large variety in building heights in this area, the volume of Hourglass is composed of three blocks with different heights of up to 80 meters, in an L-shaped footprint. The building is sustainable, multifunctional, flexible and futureproof and has therefore been awarded with a ‘BREEAM-Excellent’ certificate.

sculpture
The design of Hourglass was inspired by Constantin Brâncusi’s geometric sculptures. Furthermore, its striking silhouette was a logical result of one of the main tenants’ need for a working environment that combines both openness and privacy. To cater to that wish, Dam & Partners Architecten designed an office space with several atriums that narrow or widen towards to the top, as well as floors that reach from façade to façade.
“This is how we created diversity in floor usage. As the work spaces surrounding the atriums are adjacent to the windows and more or less the same depth, the building automatically gets the shape of an hourglass. Because it is actually nothing more than a shell enclosing that usage,” explains architect Diederik Dam.
Its tailored silhouette, light sandstone and ample usage of glass lend the building a timeless and international appeal. The monumentality – in the form of sloping natural stone facades with glass incisions, is reinforced by the positioning of the windows in the facade: upright for optimal reflection. Upon entering the building, visitors are stunned by the spaciousness of the numerous atriums, the high green wall and the use of warm materials. The interior for the office tenant – one of the largest legal service providers in The Netherlands – is designed by Powerhouse Company. Due to close collaboration, the interior and exterior of Hourglass seamlessly connect.

photography by Sebastian van Damme