Utrecht is dotted with special buildings, which you bike past regularly but know very little about. And some of these buildings are still in the make, such as Oopen, which will appear in the middle of Jaarbeursplein. Several round volumes, piled on top of each other, and gradually merging to form one high tower, surrounded by wide terraces. You’d be forgiven for not recognising this building as it isn’t there yet. It will provide space for offices and public facilities on Jaarbeursplein, more or less on the site of the skate track and taxi rank. Heatherwick Studio in England and the Dutch architectural firm Nudus were responsible for the design, and nine ‘ordinary’ Utrecht residents helped to choose the architect and the character of the building. When considering the character, the main point was that it should be a building for the people, a jolly counterpart for the city hall. Hence the name ‘Oopen’… Having said this, the public character still needs to be seen – architecture and utilisation are more than a name. The architects are doing their best to ensure that the offices, where the real money will be made, don’t determine the atmosphere. There will be cafés and shops in the broad ‘foot’ of Oopen, while the floor above will house a concert hall and a climbing wall. Right at the top, there’ll be a public rooftop terrace á la het Forum in Groningen. The upper and lower case ‘o’ in ‘Oopen’ literally reflect the shape of the building. The o-shaped discs are bigger and smaller, serrated in different ways, sometimes cut diagonally and unevenly piled up so that some of them jut out. Oopen will become the wild twin sister of the two smooth, erect, evenly matched Rabo towers a little further along. Built in 2011, they were considered massively high at 103 metres. Oopen will be 105 metres, just a tiny bit higher. The Rabo towers were designed by Kraaijvanger, a respectable architectural firm from Rotterdam. Heatherwick Studio designs, however, are highly imaginative. This is the firm that designed the Dr Seuss-inspired Little Island in New York and an unfolding, diamond-shaped glasshouse for Woolbeding Gardens in Sussex. So expectations are high. All things being equal, Oopen will be completed in 2028.