Technical realization - CU building

As can be seen in the figure, the buildings most used material is glulam. Glulam is an engineered timber featuring a relatively low embodied energy while providing a decent resistance to forces and bending moments. The timber frame has been placed on an 8 by 8 meter grid. The overspan is realized by 2 glulam longitudinal trusses which are connected to each other by 3 accoya glulam transversal trusses. Accoya wood is infused wood, which is therefore resistant to the environment. This allows it to maintain its natural timber look and does not need regular maintenance. One can notice that the overspanning structure features 2 times 3 thicker beams. These are to cover a 16 meters span and minorly interfere with practical and architectural aspects. However, a thicker beam underneath was undesirable and therefore a different, more complex, a solution was found in a transversal beam.  

The higher moment of inertia of the SHS profile of the steel supports allows the supports to be quite slender and lower the amount of used steel. To further decrease the width of the supports and material usage, the steel supports will be connected to the first floor of Microlab after placements. This causes the buckling length to be decreased from 22 meters to 13 meters.  

The building features 3 main load paths. The most simple path is at the west-side of the structure. The loads will be transferred through longitudinal orientated floor system, which is supported by transversal beams. The second load path is the main load path for the overspanning structure. The loads are transferred through the transversal orientated floor system, which is supported by longitudinal beams and the longitudinal trusses. The loads through the longitudinal beams go through the glulam columns which are supported by the transversal trusses.  The longitudinal trusses transfer the loads to the timber columns and the steel supports. The decision to keep the two slendered inner supports, and thus the third load path, is based on two architectural reasons; the uncomfortable look of only 2 outer supports, the need for extra transversal trusses and thicker beams when left.  

The main stability of the building is provided by the two CLT cores. The Kerto Ripa floor slabs are regarded as a stiff floor system. Therefore they ‘distribute’ the stability of the cores to the rest of the structure. While the two types of trusses in the building are stable elements, they don’t cover the whole structure and therefore have a minor impact of the overall stability.  

Our building uses ATES, heat pumps, heat recovery systems and natural ventilation. This helps reduce the Operational energy demand from 36.5 kWh/m2, which is already good, to just 21.23 for heated and ventilated areas. We also use low embodied energy material for construction and recycle much of material from demolition, which allows us to be just 4.2 GJ/m2, installations included.

The apartments receive constant supply of HVAC, which is 21.23 kWh/m2 yearly operational energy demand. The public space is heated indirectly - by the air exiting the apartments, due to heat transmission through walls and also from the heated space on the ground floor, using the atrium for chimney effect.

Air can enter the apartment either naturally or mechanically. It then gets heated up evenly by floor heating, and then enters the process of recirculation through a heat recovery system, which is designed with ATES system.