The Project

The BNP Paribas Fortis new head office at Warandeberg, Brussels was constructed to meet the most advanced standards in terms of sustainability and working comfort.

With a gross area of around 100,000 m² and capacity for 4,500 workstations it contains an auditorium, a conference centre, underground parking for 268 cars, 40 motorcycles and 330 bicycles, and a shopping arcade.

Sustainability Objectives

The building’s passive design uses the lower floor level for Seasonal Thermal Energy Storage (STES), with no less than 14,000 m³ of water stored under the building, enough for four Olympic-sized swimming pools.

The heat stored in the water during the summer months can be used in the winter, without using fossil fuels. The building also has an extensive green roof of 5,500 m², which is visible from several places, as well as a large number of photovoltaic panels.

KNX Solution

KNX was selected as the building automation system to achieve the sustainability objectives.

To regulate the lighting throughout the building according to room occupancy levels and measured natural daylight, detectors were installed in the following areas:.

Analogue detectors (x 697pcs) were placed in:

  • sanitary areas
  • small and medium sized rooms
  • corridors
  • large open spaces
  • showers (IP65)
  • underground car parks

KNX detectors (x 286pcs) were placed in:

  • stairwells
  • stairwells and lift shafts

The client opted for high-quality sensors from B.E.G. The PD2N-KNX and PD4N-KNX models with two integrated light sensors are able to achieve very precise light measurements. The sensors are  suitable for interiors with difficult lighting situations, e.g. for the corridors and prominent stairwells into which light enters from several window fronts at the same time.

Particularly high energy savings, as well as a high level of hygiene can be achieved by presence detection in toilet rooms. Here, the project managers chose the B.E.G. detector PD3N.


The new BNP Paribas headquarters was awarded the BREEAM Excellent Label following its completion in 2021.This is a testament to the energy optimisation capabilities of KNX; the only open Worldwide Standard for controls in both commercial and residential buildings.

BNP Stairs1

BNP Tables1

BNP Garage1