hoofdfoto1 newsletter #3


    Environmental and Urban Planning Certification and Permit Application

    A procedure in two stages

    The Montagne du Parc|Warandeberg Project within the trajectory of the permitting requests; an outline of the fundamentals of our not so common approach.

    From the exchanges and reflections made during the preparatory competition stage the following major concerns quickly turned up:
    - accessibility (for employees, visitors, logistics,..);
    - needs of the project and the neighbourhood, shared infrastructure, synergies with neighbours;
    - opportunities and possibilities to create a better link between upper- and downtown.

    To observe these considerations and the possible opportunities at an early enough stage of the project, it was decided, together with the Regional and City administrations, to go for a procedure in two stages: first an environmental and urban planning certificate application including a mandatory impact  study* and only after, a permit application.

    Several analyses about access opportunities, socio-economic synergies and energetic solutions have occurred. This lead to several alternatives and variations that together with a basic proposal were included in the certificate application file. In this way it was possible to study during the impact study the effects of the project and its alternatives, both socially and economically, on life in general and at an urban level, at an early conceptual phase when the project could still be influenced and enriched.

    Meanwhile the (first) certification phase reached a positive conclusion.
    Our urban and environmental certification application was introduced to the Region in April 2014. An impact study, realised between October 2014 and May 2015, resulted in numerous recommendations that required important concept changes and has resulted in an Amended Certification file being introduced on 14th August 2015 to the Region. The public inquiry happened between 27th August and 25th September 2015. Following the public inquiry the Certification file received a positive advice from the Consultation Commission on 20th October 2015. Meanwhile, the urban as well as the environmental certificate have been delivered by the administrations.

    * The Brussels Town Planning Code (CoBAT) provides for a mandatory impact study for public or private projects that particularly because of their size, nature or location, can drastically affect the (urban) environment, or which may have serious social or economic consequences.



    The "Amended Certification File"

    How and to what extent the results of the impact study have influenced the further evolution of the project?

    In designing the new project, much attention was given to the project’s site layout, its scale and the context of the city fabric. The historical morphology of the inner city - its streets , squares and spaces – were interpreted and applied by the architects in their project through the use of a ‘building block with courtyards’. Following the recommendations of the impact study the designed volume articulated in a better way towards the surrounding buildings and the (public) space.




    The new volume follows the historical building line, re-tracing the curved route of the urban development plan of Henri Maquet (1903). Through partially inside-outside spaces (arcades, passages to inner courtyards) a connection is sought with the public space. In search for a coherent approach between volume and form, the swinging volume is lower than the existing towers and interacts through its fluctuating height with the surrounding buildings and the topography of the site. The average height of the surrounding buildings is 32m. The highest point of the existing Montagne du Parc building is 42,30m whereas the project’s highest point is at 34,50m. Although the project is 2,50m higher than the average of the surrounding buildings, it is 7,80m lower that the highest point of the existing building.

    However there are two reasons to differentiate this height calculation: - the calculation gives a limited view of the appreciation of the different heights relative to the project; the heights of the surrounding buildings show very large differences between them; - the project is situated on the border between the upper and lower part of the city and a difference in altitude of approximatively 13m, the height differences are experienced in a special way.

    The recommendation of the impact study requesting special attention for the limited height of the Bozar building was followed, the height at the corner of the Baron Horta street was reduced from with 1,25m in the amended certificate file.  The setbacks in the façades refer to the cornice height of the neighbouring buildings, respectively the Chancellerie and Bozar building.


    The street façades strongly define the identity of the building; showing a delicate and elegant bearing structure. In search for an esthetical balance between openness of the façade and urban integration, between day light and structural necessity, the rhythm of 1,35m distance between columns was chosen. Vertical columns, prefabricated with white concrete and green iridescent gravel aggregate, have variable sections depending on the façade details and respective heights which combine to create a smooth curved feature. Variations in rhythm articulate the building volume whilst the accesses emphasize the level transitions and the outline of the building volumetry. By this, a strong dynamic is introduced enriching the façade. Combining the irregular form of the columns, elliptical designs are created that are defined following specific principles, macro as well as on micro-scale, that overlap the regular basic pattern and enhance the already strong dynamic of the façade.


    The  building volume searched for the right proportion between mass and void, between compactness and day light. The form of the internal courtyards and their respective mutual ratio have been reconsidered following the recommendations. The resulting design not only has impacted the created fluent volume and the organisation of the different levels, but also has, by modifying the mutual connections between the voids, considerably improved the gain of daylight. The open inner courtyards provide approximatively 1400m² of green space including a large garden of more than 500m².


    The recommendation to enhance the existing important pedestrian flows between the lower and upper city, has been considered since the competition phase of the project. As a result rue Montagne du Parc and rue Baron Horta will be largely returned to the pedestrians.  By relocating the existing parking access on the rue Baron Horta, a unique opportunity emerges to revive this public space in coherence with the urban fabric. Still with the intention of linking the lower and upper city, the project allows the creation of an urban elevator within its own limits. A public elevator (in coordination with the public authorities) would allow to cross the declivity more easily. In addition, the newly created internal street links the urban elevator and the upper entrance to the building with the metro station Parc and the tram stop situated in rue Royale. For the Montagne du Parc street a proper balance between motorised traffic (logistical access) and pedestrian flow is proposed.


    The impact study recommends a mix of activities on a socio-economic level.  

    Out of our ambition to realise an ‘open’ headquarter, new facilities and interesting concepts will be integrated.  Possible synergies with Bozar are analysed (embedding an info/ticketing site, a foyer (Bozar-café),  shared use of a seminar centre...). What kind of urban activities or concepts it will be, is not yet determined; however, both commercial as collective activities along the Rue Ravenstein, Rue Baron Horta and on the level of Rue Royale have been requested in the certification file. In that way we integrate semi-public environments inside, where we not only increase the intrinsic quality of the building but invest together with Bozar in restoring liveability to the site, even outside office hours. 

    In response to the recommendation to make the urban functions visible in the streetscape, the architects have broken up the façade rhythm over part of the ground floor. An arcade is articulated as a transitional space between the street, the urban function and the shared courtyard. On the other wall portion, along the Rue Ravenstein, commercial surfaces are shifted to the front line.


    “Structural sustainability” is the driving force within the design development. Bearing outside façades preserve the open plan ensuring that new layouts remain possible in the future.   To this quality of flexibility, the notion of 'sustainable maintenance' is grafted; a rational technical approach were good control of maintenance costs and energy consumption is the challenge. The technical installations are simple and centralised in the underground area  where a water basin provides thermal energy for heating and cooling. This integrated approach makes it possible to achieve the ambitious standards for passive building and BREEAM certification.


    The environmental impact linked to a building is largely determined during the design phase, but also the assessment of the environmental impact of our demolition and construction works are very important. Are we efficiently dealing with energy and water consumption? How do we get a grip on effects such as noise, vibration and pollution? 

    In order to fully implement the execution phase two main aspects are important: drawing up clear specifications and good site management. The contractor we ask for a 'sustainable' site management with a focus on managing and reducing the environmental impact of the site: responsible energy and water consumption, an efficient traffic plan and a judicious choice of building techniques and materials for the site organisation.  Respecting the BREEAM criteria imposed; stricter than the recommended framework by the impact study and the legal framework.

    1.    Measuring and  monitoring 

    Prior to the start of the works, the acoustic levels and vibrations at the level of the adjoining buildings are measured. Acoustic measurements are carried out on the outside of the buildings near the facades. Recording of vibrations occur in the areas behind the respective facades and in the sensitive areas in relation to their use. These prior measurements make it possible to establish a reference for the entire site which the Montagne du Parc building is located. 

    During the execution phase (both demolition as well as construction works), a continuous monitoring is foreseen in order to ensure that the environmental impact of the site respects the limit values defined in the specification and in relation to the frame of reference. This procedure is initiated in order to check the acoustical and vibration impact of the site on his immediate surroundings and to remediate when necessary. 

    2. Follow-up contractual engagements  

    The project definition contains clear clauses (good/best practice) relating to an environmentally friendly site, in which the level of ambition to which the tendering contractors must comply, is also determined. 

    The contractor will be required to report periodically on the management of noise,vibration and air pollution and compliance on proximity and accessibility standards. He is also requested to submit and keep track of a waste management plan and site layout plan. Traceability and assurance that the objectives relating to reuse effectively achieved critical. Also, reviews of the use and transport schedules to and from the site must be strictly followed. Traceability and the guarantee that the objectives relating to reuse are effectively achieved, are of utmost importance. Also, reviews of the consumption and transport schedules to and from the site will be strictly monitored. 

    Moreover, the project team Montagne du Parc I Warandeberg warrants careful monitoring; all environmental risks linked to the execution phase will be inventoried and evaluated in terms of measures to reduce site disturbance and the normative and legal framework thereabouts.  Specific tasks on dissemination of information and answers to questions regarding the site organisation will be handled by a site communication responsible.