Foundation repair of De Waag in Amsterdam


De Waag was originally built as a city gate. This St. Anthony gate was part of the city walls that were erected between 1481 and 1494. At the end of the sixteenth century Amsterdam expanded beyond the city walls. The St. Anthony gate lost its original function. Between 1603 and 1613 the city walls were demolished. In 1614 the street level was raised to create Nieuwmarkt square as it is known today. Not only did the canals running in front of De Waag disappear underneath the pavement but also part of the brickwork of the building. Now this is the basement of the building.

Between 1617 and 1618 multiple storeys were built over the courtyard of St. Anthony gate. Several guilds (scriveners, masons, wooden shoe makers, surgeons, goldsmiths and city guards) moved into the enlarged building. Each guild had its own entrance through one of the towers. In the tower of the masons guild intricate brickwork is still telling the story of seventeenth century craftsmanship. De Waag took its present form in 1690-1691 by the construction of a large domed room, surmounting a central tower. The interior dates from this period.

In the nineteenth century De Waag served different purposes amongst which housing the Amsterdam museum and later on also the Jewish Historical Museum. Between 1989 and 1994 the building was left empty. After that restoration was carried out aiming to solve amongst others structural problems. De Waag finally got new occupants being a restaurant on the ground floor and the intermediate floor and a new media company on the upper floors. The kitchen and the toilets of the restaurant are in the basement.

Task: The structural problems have persisted causing subsidence in various degrees to different parts of De Waag. In order to solve these problems permanently a new foundation will be put underneath the building. For this purpose the basement needs to be temporarily vacated. The kitchen and toilets will be housed in temporary units during the process of foundation repair. A new kitchen and new toilets will be installed in the basement afterwards. Erfgoed Installaties was asked to come up with a plan for dealing with the electrical and mechanical systems during the three stages of the foundation repair, transfer to the temporary units, demolition of the old systems and installing the new kitchen and toilets.

Approach: The technical systems have been altered many times over the years and were tucked away behind panels. Revision drawings and system descriptions were missing. Therefore a survey was carried out first. An understanding of every corner of the building was needed in order to find space for cables and pipes respectful of the historic interior. Original ideas and careful planning were needed.

Results: Despite the limited time that was available the plan for the electrical and mechanical systems was delivered on schedule. In addition several other issues like the emergency lighting system, the sprinkler system and the indoor climate were solved. The fire safety of this listed building shall be guaranteed in all three stages of the project.

Client: The city of Amsterdam

Completion: 2013