26 July 2021

Kantoor 2023: a new sustainable and circular building in Brussels

In 2023, 3,000 Brussels civil servants will start working in Kantoor 2023, a residential-work complex aiming to serve as an example for future public construction projects in the city. The complex is the result of a Competitive Procedure with Negotiation, launched by the Agency for Facility Operations from Procura+ Participant Government of Flanders, for the procurement of the design and construction of a new building for city staff.

The procurement has resulted in the renovation of the two towers of the World Trade Center (WTC) in Brussels, with construction of a new block annexed between the towers. In terms of circularity, the current buildings are being used to the maximum. 62% of the current building will be reused or recycled. The parts that are broken down are being given a new life – for instance, 30,000 tonnes of the broken concrete is going to be used as recycled granulates in the new concrete, and will be Cradle-to-cradle (C2C) certified. Up to 95% of the new materials will be C2C certified.

Circular thinking is not only based on recycling and certification. It is also conceived in a forward-looking manner. The buildings are being designed in a way to enable functions to be switched for residential or non-residential use. In the beginning the towers will be used alternately per story for office and residential functions. The facade, HVAC, lifts, fire-safety, etc. are being designed so that they can serve various scenarios of usage. The neutral structure will ensure that offices, homes and hotel rooms be furnished within the same basic structure. The building will therefore not only focus on today’s needs, but will also be adaptable to tomorrow’s needs.

In terms of sustainable design, the roofs of the building and the conservatory are equipped with solar panels to the maximum. Heat and cold will be extracted from the ground with a cold-heat storage system, which will cover more than 60% of the energy demand. An exchange of energy between the functions will further reduce energy consumption.

In terms of biodiversity and green spaces, the structures include 2,400m2 of rooftop gardens, 2,850m2 of ‘air purifying’ facades, green office floors with 400 trees and 1,000 local plants, a greenhouse with 1,000m2 of unpaved surface and 25 large trees.

More about the results of the project, the tender objectives, and the requirements/criteria relating to sustainability and circularity, can be found here.