Sustainable childcare centre building – times three
The city of Lünen is meeting the demand for childcare facilities for young families with the construction of three new daycare centres. All three buildings are based on the same design by the architectural firm Lutz Sommer and thus fulfil the requirements of the clients, who attach great importance to energy efficiency. Designed as a passive house construction, for example, the DuoPlus energy-saving roof system from Kalzip was used. The design requirements for the rooms were also realised thanks to the special floor plan, which can also be seen from a bird’s eye view.
One special feature becomes immediately apparent when looking at the three daycare centres: all three buildings were constructed according to the same design. Rooms play a key role in daycare centres and are often seen as “educational instances”. The floor plan of the buildings suggests that no two rooms are the same. The colour concept makes the division into groups obvious and thus provides orientation for the children. But the shape and size of the rooms also enable the realisation of different educational concepts.
The view from above
As hardly any of the rooms are laid out at right angles, it is not surprising that the single-storey buildings do not have a simple geometric shape when viewed from above. In the form of an incompletely assembled polygon, the buildings fan out into individually designed inner courtyards with play areas. On the other side, the roof ends with an almost crescent-shaped segment of a circle that is inclined towards the centre and converges into an eaves point. A water drainage system was specially planned for this and individually welded together. The entrance area is again inviting with a traditional pitched roof structure.
Precise planning for the Kalzip roof
In order to be able to reproduce this unusual roof shape the decision was made in favour of standing seam profiled sheets from Kalzip, which were produced specifically for this building shape. The polygonal surface in particular, which is arranged towards the inner courtyard already required conically shaped profiled sheets. A great deal of detailed work went into the planning and execution: instead of dividing the surface into five independent trapezoids, a continuous roof surface was created that creates a harmonious appearance despite the conically shaped profiled sheets and different inclinations to each other. The simple roof surfaces could be realised in the standard 65/400 construction width. In total, each roof consists of around 850 m² of conical Kalzip profiled sheets and 140 m² of Kalzip 65/400 in a stucco design.
Efficient thanks to energy-saving roof
For the day care centres Kleiner Kreisel, Dammwiese and Kinderhaus Lünen, it was clear from an early stage that the buildings should be particularly energy efficient. To minimise the amount of energy lost through the outer shell, the energy-saving roof system DuoPlus from Kalzip was chosen during the planning phase. Thanks to its high insulation performance, the system structure minimises heat loss in winter and protects against heating up due to solar radiation in summer.
The design principle of the Kalzip DuoPlus roof structure consists of the thermal separation of the outer roof covering and the inner load-bearing shell. A vapour barrier and a layer of impact-resistant insulation boards were first laid on the supporting structure. Using approved connecting elements, the systems elements were then mounted on this substructure. The clip rail is designed to accommodate the clip adapters with composite clips as an economical and secure fastening surface.
The E-clips were simply attached to the rail by rotating them in accordance with the spacing of the conical standing seam profiled sheets. Consisting of a metal core encased in a glass fibre-reinforced, UV-resistant polyamide, the E-clip ensures particularly low thermal conductivity. The height of the E-clip also ensures that there is sufficient space between the first impact-resistant insulation layer and the roof cladding for an additional insulation layer. This allowed the roofers to gradually lay the soft mineral wool insulation around the E-clips. The aluminium profile sheets were placed on the protruding clip heads and flanged at the standing seams using a flanging machine.