From 2024, Flemish government employees from a number of Brussels buildings will move into a unique, integrally accessible, sustainable and largely circular building in the Brussels North Quarter, called the Belpaire building, on the site of the former WTC towers.

The project, tentatively named Kantoor2023, achieved an "excellent" score on the GRO sustainability meter and is a first in Flanders in terms of circular construction.

Ingenium guided Het Facilitair Bedrijf van de Vlaamse overheid in striving for a project that links maximum sustainability to a flexible, comfortable and healthy working environment. The Smart Readiness Indicator was also tested on this building.

An innovative project

The Marie-Elisabeth Belpaire Building is part of an innovative project, ZIN in No(o)rd.

Towers I and II of the WTC complex on Simon Bolivarlaan in Brussels' North Quarter were transformed into a unique concept with a mix of living and working through alternating office and residential floors.

With this building, the Flemish government is once again raising the bar in terms of sustainability. The building makes a major contribution to achieving the Flemish government's 2030 climate objective.

Highest possible score

Office2023 achieves the highest possible score on the GRO sustainability meter. Achieving the score "excellent" is no easy task. The criteria by which sustainability is measured translate into concrete requirements that are sometimes difficult to reconcile. A classic example is daylight. Providing lots of daylight can lead to overheating in the summer, resulting in higher indoor temperatures. When designing Office2023, as many factors as possible were taken into account from the very first stroke of the pen. Thanks to that integrated approach, the building achieves an excellent score. The design scores well in all areas and benefits people, planet and profit. For example, the design scores well in terms of acoustics, there will be plenty of daylight, a panoramic view, excellent indoor air quality ...

A combined office and residential complex

Office2023 is also another unique concept because of the mix use building: a city within a city with interaction to the neighborhood. The zebra concept is a mix of living and working through alternating office and residential floors.

The site comprises about 110,000 sq. m. It includes 75,000 m² offices, 14,000 m² residential facilities, 16,000 m² hotel, as well as sports, leisure, hospitality and commercial areas.

View here the video of the zebra concept.

The mix of offices and residential floors keeps it from being dead at night. Public places such as a sports center, catering establishments, a conservatory ... ensure that even outside office hours there is something to do. 24/7. And that everywhere. The building has no back facade, all sides are equally valuable and equally active.

Sustainable and circular

With this new office building, the Flemish government scores even better in terms of sustainability. According to the GRO sustainability meter, it achieves a result of 'excellent' and the E-level (E15) is the lowest of all its buildings. This is due in part to a cold-heat storage system in which heat and cold are extracted from the ground and to a far-reaching application of solar panels on the roof and side walls.

Urban mining: The underground floors and circulation cores of the former WTC I and II buildings were preserved. What did get demolished was given new life. The new building consists of 68% preserved, on-site reused or recycled materials. Preservation and reuse are very pure forms of circularity for the sake of reducing waste and new construction materials and avoiding transportation and processing of both.

Use of materials: cradle2cradle: waste as nutrient for new products

Currently, the two WTC towers are being dismantled. The radiators, the ceilings, the carpet tiles ... all go out. These materials are not considered waste, but raw materials. Nor do they go to the landfill, but are reused, sold or recycled so that the cycle closes. Thus, up to 95% of the material can be recovered or recycled. The new materials, which will be used in the construction, also receive a materials passport and are inventoried. Knowing exactly which materials were used in which place makes it easy to find them if a material needs to be replaced. Thanks to the materials passport, the technical properties and lifespan are known and you know how to disassemble this material.

Future adaptability: The building is designed with a certain "neutrality." For example, the facade is designed to work for offices, residences and hotel rooms. The functions behind it are interchangeable without having to make interventions on the facade.

Water cycle: Rainwater and drainage water is treated to reduce city water needs by half.

Technical installations: controlled ventilations and opening windows increase user comfort

Energy Exchange: The functions in the building need energy at different times. An office mainly during the day, housing mainly in the morning and evening. Between the functions, energy exchange ensures the efficient use of energy and optimal depletion of energy generators.

Organic waste: through biomass

Energy efficient

Office2023 has achieved an E-level of E15. It is a nearly zero-energy building. This means that little energy is needed for heating, ventilation, cooling... and that the necessary energy is obtained from renewable sources. Solar panels were installed on the roof as well as in the canopies on the facades, which also serve as sunshades. There is also a cold-heat storage system whereby a heat and cold exchange with the groundwater is installed, and energy-efficient appliances were chosen.

Smart

Spurred by smart grids and other new energy technology coming to market to make buildings even more energy efficient, the European Commission's DG Energy launched a Smart Readiness Indicator (SRI). This indicator is under development and aims to indicate where there is still improvement potential for a given building. By applying the SRI, a number of additional opportunities were explored to make Office2023 even more energy efficient.

Ingenium

Unlike in many other projects, Ingenium did not act in this project as a classical engineering firm for the engineering of the building. Under a framework contract with HFB, Ingenium guided this project through the various phases of the change process, paying specific attention to sustainability, energy neutrality and maintenance. During the evaluations and negotiations of the submitted price offers, we advised the client in matching high ambitions with realistic expectations.

During the development of the project, we followed the established principles. And also during the operation phase, supported by an adequate BIM model, we ensured the monitoring of the program of requirements through commissioning. In particular, we guided the Flemish Government in the implementation of several hundred charging stations in the parking lot, which was technically a real challenge. This way of working strikes a balance between comfort of and for the user, the sustainability including energy neutrality of the building and the impact of changing legislation. Not an obvious balancing act for smart building experts.

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