In a world that is constantly changing, the demand for highly trained engineers is only increasing. For example, the new applications that need to be developed to achieve the goals of the Paris Climate Agreement or the realisation of a large number of new (sustainable) homes to resolve the housing shortage. Engineers are the people that form the basis of realising these essential facilities. It’s their job to provide insight and substantiate ideas into achievable solutions while ensuring all requirements, preconditions, and laws and regulations are met.
 

“Brainstorming solutions and making ideas achievable; that’s exactly what I love about my job as a structural engineer,” says Saskia. “I like the concept phase of projects, where you sit down with various parties involved to develop the proposed idea further. An architect, for example, can come up with the most beautiful buildings, but transforming these ideas into achievable solutions can present a complex puzzle. There is much to consider. One side of this is that the architectural design must be safeguarded as much as possible; the other side is that dozens of disciplines come together in one building, all of which occupy common ground. As a structural engineer, I examine exactly how the structure of the building should be organised, which materials are required, the consequences of various choices, and how the interfaces between the various disciplines should be aligned to work harmoniously towards a well- functioning and achievable whole.”
 

There is still a lot to be achieved in the structure of buildings when it comes to sustainability. Saskia explains: “My ideal scenario is to work on this structural puzzle with a view to sustainability. I find sustainability very interesting, and I am also actively busy with this at home. Since this year, I have been studying the role sustainability plays in building structures, and I’m investigating how to apply this at CAE. I will eventually structure the information I have collected, which relates to the use of materials and the connections used in structures. For example, the more flexible the building structure, the easier connections can be taken apart, the better a building structure can be disassembled and reused elsewhere. I’m very pleased to have the chance to do this in addition to my projects. What’s also really nice is that I have regular contact with the other divisions of Iv and get to learn more about how they deal with sustainability within their projects.”
 

The transformation of the Baumann Church in Rotterdam is an example of a project in which CAE was responsible for figuring out the ‘structural puzzle’ and whereby sustainability played an important role. The outer façade has been retained as much as possible to preserve the buildings’ characteristics and monumental character. However, the inside of the building has been completely transformed into a modern residential complex housing 33 apartments and penthouses while preserving the existing structure where possible. And this presented some structural challenges.
 

Only the outer walls and the front and rear façades remain following the transformation from a church to a residential complex. The space that was originally the church hall has been completely adapted. The roof has also been removed to create a transparent block with two more housing layers. In addition to the feasibility study, CAE also provided technical detailing and implementation guidance.

Two types of structures have been used in the building. The new structure has been designed as light as possible where it burdens the existing structure. A more solid structure has been applied where the foundationn has been completely renewed and complies with current quality requirements to minimise impact noise between apartments. This is the case for the nave of the church building, which has been filled with a new system of hollow-core slab floors and sandstone/ limestone walls with foundations. A new foundation with a  concrete core in the front of the building also guarantees the stability of the extra volume realised on the roof. Where possible, existing concrete piles have been used.

At the rear of the building is a sunken cellar. The new structure is more complex here. Because the new structure at the back of the building makes more contact with the existing structure, the existing piles were retained as much as possible. A light structure with composite steel deck floors has been applied, and the existing walls are connected to the new floors. The challenge here was aligning the new structure with the existing piles (creating straight lines downwards). But as discovered with the existing structure, this did not always work out well, which resulted in more complex transfers. The new structure and the archive drawings were therefore drawn up and calculated in a 3D model. Ultimately, the solution was found in a transfer structure that connected the new structure to the existing piles and adhered to the architect’s layout.
 

A number of windows in the outer walls have been knocked through to create a balcony on specific storeys. The balconies are pretty large, and integrating these into the existing structure was also a complex task in terms of logistics, detailing, foundations, and obtaining the desired rigidness (for correct load bearing). The desired size of the balconies was achieved by reducing the weight in the concrete by using steel consoles, making it possible to use the existing foundations.
 

This wholly transformed housing complex will be completed in early 2022. Residents will live here in a beautiful and central location and truly unique home. From the outside, the residential complex still resembles the old church, but inside the building, you will find modern apartments with character details such as striking stained- glass windows. Saskia: “This is also a project of which I can say: I am proud of it! We did an excellent job of it together. Such a major transformation from a monumental church to a residential building is not something that happens very often.”