A gas factory used to operate in the bustling Utrecht city centre. After it was demolished, the empty plot remained undeveloped for a considerable time. After revitalizing the contaminated soil, the municipality of Utrecht decided to transform the area into a recreational park, the Griftpark. The urban plan consists mainly of a north-south central axis, unfolding amidst the park boundaries. The children's city farm Griftsteede, is the natural crowning of the straight route, ending in a spiral curled structure, reminiscing a crosier. The complex consists of the main building accommodating the children's' farm, an Environmental District Center, a space for educational information on nature topics, a playground and some detached stables.

​

A trial and error design process followed, investigating the possibilities of different spiral structures.

​

From this study, a volume was developed that has its origins in the two-dimensional ground plane and is made up of a grid of main girders and connecting purlins. The main girders all have the same in-between distance and angle. The connecting purlins are parallel to each other, placed in the same distance. The interplay of lines, gradually forms smaller whirls around an enclosed circle, resulting in a cochlear pattern. The main building acquires a fan-shaped plan. The girders all have a fixed vertical angle compared to the ground plane, transforming the two-dimensional structure into a spatial fabric. The purlins in the sloping roof plane serve as contours.

​

All the girders are of the same profile and the same goes for the purlins. Both these structural elements are made out of wood. The lucid structure results in just two types of joints. The interconnection of the girders in one hand, and the structural connection between a girder and a purlin on the other. Minimizing the number of distinctive joints, allows effortless construction, rendering the structure very affordable.

​

The climate control installation is kept as simple as possible. Natural ventilation is applied in the majority of times. The big eaves provide plenty of shade and prevent the building from heating up. Only the upper floor has extra mechanical facilities installed to avoid overheating. The stables are ventilated naturally through a slot between the roof and the window frames, allowing a permanent fresh airflow. The large eaves and the brick walls contribute to a comfortable micro-climate as well.

​

In the central hall, the wooden structures are left exposed. The high strip of windows in the offices on the upper storey lifts the copper roof visually. From the central hall, one sees both the top of the roof, as well as the lowest point, where the flow of the shape is similar to a funnel.

​

By combining materials such as glass, copper, steel, brick and wood, the building leaves a modern, yet playful and natural impression to the visitor, providing a place with spatial warmth, where children and nature can meet.