The façade of the RAL building in Bonn unmistakeably showcases the identity of the client and user of the building. A total of 428 Schüco ALB large louvre blades with motorised solar tracking provide shading and reduced heat gain for almost all of the offices and meeting rooms. What makes this building really stand out is that the glass louvre blades are screen printed in the virtually endless RAL colour spectrum, which been synonymous with the institute for over 90 years.
The representative, easy-access and incredibly energy-efficient office and warehouse building of RAL – Deutsches Institut für Gütesicherung und Kennzeichnung (German Institute for Quality Assurance and Labelling), along with its subsidiary RAL gGmbH, is situated at the Am Mühlenbach business park in Bonn. With the return to its home town of Bonn, the long-established institute also wanted to embody its values in the newbuild completed in 2017. “Functionality, quality of life, identity at the highest technical and sustainable level using the latest sophisticated components and technology relied on in day-to-day operations, with products and services that are quality assured by RAL.”
The building was also to reach beyond these “inner values” in its external appearance and be self-confident, high-class and attractive, to clearly allude to the core expertise of the RAL family and stand out from the crowd.
Exciting building shape
Architectural practice Frank Piotrowski added a touch of fun to the west side of the new technology park “Am Mühlenbach”, with its strictly rectangular functional buildings, by designing a slightly curving building structure. The design therefore took inspiration from the adjacent spacious, natural flood plain which lends its name to the Mühlenbach business park. The tension between rectangular and rounded basic forms gave the newbuild the chance to develop unusual room configurations within the required space allocation.
The most heavily used and, due to its northern location, most difficult to utilise area of the building on Sankt Augustiner Straße was designed to be strictly orthogonal. Located there are the necessary underground car park, the main warehouse and the highly technological colour laboratories on the ground floor as well as an office atrium on the upper floor. In this position, the warehouse space can be filled and emptied seamlessly without interruption. The windowless warehouse façade is also used as advertising space, with a white backlit logo making the new RAL institute headquarters visible and familiar.
The building depth has enabled the creation of a three-part office use concept on the upper floor, which turns into an atrium in the central area. The access corridors are also lit and visually enhanced. The management area there can be accessed separately via the staircase.
Open and closed façade areas
In contrast to the strictly rectangular part of the building towards Sankt Augustiner Straße, a gently curving structure was built in the west section. The basement level there houses the building technology system and the historical archives. The ground floor holds a self-sufficient public conference area with a view of the green Mühlenbach plain. The upper floor is exclusively reserved for a two-part office use concept. At the intersection of the two parts of the building is the central entrance area with reception and access to the only staircase connected to the entire building.
Solar sails from the RAL colour spectrum
The exciting contrast between building shapes is continued in the façade design. A ground floor that appears solid with a natural stone façade made from German blaubank muschelkalk serves as the base for the light upper floor with room-height glazing and a flat roof that that noticeably overhangs on all sides. Above the base, the specially developed glass louvre blades really come into their own as sun shading.
The floor-to-ceiling glazed units rotate around their centre axis while motors allow them to follow the position of the sun and provide soft lighting conditions to the adjacent rooms thanks to their translucent perforated coating. With their finely graduated colour design, they are a striking indication of one of the core skills of the client, as they have been designed in the colours from the RAL design colour system. At the same time, they open up a new area of application, as RAL colours as coatings for glass panels have not yet been standardised.
The system of external sun shading is based on the Schüco ALB large louvre blade system in terms of technology. The active glass louvre blades mounted on the façade are designed in over 80 different colours and measure 3.00 or 3.50 metres high, approximately 50 centimetres wide and weigh 100 or 120 kilogrammes apiece. They can be rotated on a radius of 90° and can thereby automatically follow the angle of the sun. The motors required for this are integrated in the concealed aluminium load-bearing profiles. Linear drives with a force of 3000 N each ensure that the 428 louvre blades follow the angle of the sun quietly and accurately.
The Schüco FW 50+.SI façade with electrochromic glass from Saint-Gobain is another innovation that was used in front of some meeting rooms and offices, which do not have any sun shading by means of vertical louvre blades. The light transmission of this dynamically tintable glass can be regulated between 1% and 60% according to requirements across four levels. Depending on the solar radiation, shading and heat gain can be controlled variably.
The technologically advanced sun shading, façade and window systems with sophisticated designs were constructed in full by experienced metal fabricator and Schüco partner company Keskin Fensterbau GmbH, based in Troisdorf.
Energy efficiency and ecology at the highest level
All external surfaces of the RAL building are highly insulated, making it possible to dramatically slow down the discharge of internal heat and heat from outside, despite the large windows. The natural light and heat is used to reduce the additional artificial light and heat requirements. Controlled ventilation using heat exchangers extracts the warmth from the used air and feeds it back into the fresh air. Thanks to these measures, the primary energy requirements of the building are 52 kWh/(m².a), well within the strict specifications of 55 for a KfW efficiency house. The heat energy requirements are 5 kWh/(m².a), while the energy required for power is 30 kWh/(m².a).
The level of natural light also plays a big part in the extremely low energy consumption. The highly insulated window and façade units from Schüco help to reduce the amount of artificial light. A daylight sensor calculates the amount of daylight in each room and regulates the light intensity and colour temperature of the artificial light in the installed lamps. The energy for heating and cooling is provided by means of a geothermal heat pump in a closed circuit of 20 deep bore holes. Over the course of a year, the energy is taken from the ground in winter and fed back again in summer. The boreholes also serve as a heat source for surface heating and as an active cold source for surface cooling.
All rooms in the newbuild have a controlled, clean ventilation system with gradual individual room control for the fresh air/outside air required. Although it is still possible to open the windows (Schüco AWS 75.SI+), which are highly insulated in terms of energy efficiency and sound reduction, it is no longer strictly necessary. When the windows are closed, this means that the noise impact from the busy Sankt Augustiner Straße can be significantly reduced.
Transparent fire and smoke doors
Due to the building’s design, only one staircase is required for the entire building. The direct escape routes for all rooms are a maximum of 35 metres long. The individual fire compartments (rectangular office building, rectangular management building, round structure) are less than 400 m², meaning that additional fire protection measures are not required within the fire compartments. The door systems from the staircase to the fire compartments (underground garage, warehouse, office units) are large, glazed, self-closing fire/smoke doors. They were designed as double-leaf doors with closing sequence in the Schüco ADS 80 FR 30, Schüco Firestop T90/F90 and Schüco ADS 65.NI SP systems. The motorised locks, opening buttons and code card operation for all locked doors are all part of the easy-access architecture. Smoke is extracted from the warehouse by means of a separate smoke gas ventilator with an output of 10,000 m³ per hour.
Sustainable to the last detail
Quoted at the entrance, the RAL philosophy is in line with the holistic, sustainable building concept, which is well thought-out beyond energy efficiency right down to all the ecologically relevant details. For example, the new RAL building also has surface drainage with cisterns embedded in the ground, rooftop greening and a roof-based 10 kW photovoltaics system, which is supplemented by three quick charging stations for electric vehicles. The additional electricity required to operate the building is certified green energy from sustainable sources. The outdoor facilities were designed with nature in mind, with local shrubs and as little soil sealing as possible. The atrium in the upper floor provides a new home for a bee colony too.
Project name: RAL building, Bonn
Client: RAL gGmbH, Bonn
Architect: Frank Piotrowski architectural practice, Bonn
Fabricator: KESKIN Fensterbau GmbH, Troisdorf (Façade and sun shading) Noll GmbH, Görgeshausen (Interior design, fire and smoke protection)
Schüco systems in project
Sun shading: Schüco ALB large louvre blades
Façade: Schüco FW 50+.SI
Doors: Schüco ADS 75.SI / Schüco ADS 75 HD.HI
Windows: Schüco AWS 75.SI+
Fire and smoke doors: Schüco ADS 80 FR 30, Schüco Firestop T90/F90 and Schüco ADS 65.NI SP
Special features: Parts of the façade without vertical louvre blades in front of the offices and meeting rooms are fitted with dynamically tintable, electrochromic glass by Saint Gobain.
Article courtesy of Schüco