The exchange of information in existing buildings differs significantly from that in new construction. It is important for all partners in the construction chain to work according to the same methodology. The ILS Existing Buildings Working Group is developing new guidelines (ILS) for the exchange of information in BIM (Building Information Modeling). The new ILS is now being shared with the market for validation and feedback.

A design for an existing building must take into account existing (heritage) values, structural (im)possibilities, and the technical condition of the property. Because a BIM model is primarily a communication tool as well as a design tool, it must be practical for all partners. For the consultants you’re working with. For the person who will be surveying the building. And for the contractor responsible for construction. With the new ILS Existing Buildings, the digital approach to projects in existing buildings is optimized.

Lijnbaan 101–111, originally designed by Krijgsman and Van Duin Architects and built in 1967, has been renovated several times over the years. In 1998, D&T van Manen Architects carried out a renovation in which two large Octatube curtain wall facades were added.

Boltt has asked Octatube to investigate whether the single-pane glass in these facades can be replaced with more sustainable options. For Octatube, which is increasingly dealing with these types of sustainability issues, this presents an interesting challenge. Octatube has since contributed to the engineering of the project. The facade of the left section, designed by Mei Architects, was completed in the summer of 2023.

Together with project manager Bouwplot, Boltt developed an action plan to make the two buildings more sustainable and merge them. In a series of rapid-fire sprints, the existing conditions, the documents for the environmental permit, and the construction drawings were finalized.

Boltt used archival drawings to incorporate the existing conditions into a BIM model, which was also used for the environmental permit application. This comprehensive model also incorporates Nike’s requirements. The partition walls between the two buildings have been removed, and a new customer staircase and elevator shaft have been constructed. A new warehouse has also been added, and the entrance has been relocated from Lijnbaan 111 to Lijnbaan 105.

We created construction drawings for contractor J.P. van Eesteren. To do this, PelserHartman first created a point cloud of the existing conditions. Boltt processed this point cloud, integrated the suppliers’ models into the BIM model, and managed the process.

Together with SBB Ontwikkelen en Bouwen, a strategy was devised for the construction phase that aligned with the tight schedule and the expectations of all parties involved. Prior to the construction phase, feedback was first gathered from the contractor and co-creators on the architectural principles of the final design. The architectural principles were then incorporated into the 2D details and construction sections. The design dossier was thus aligned with the upcoming construction process.

The BIM strategy was then fully coordinated. The digital information cards developed by SBB played a key role in this process. These digital information cards specify the architectural information that must be included in the element, as well as the geometric visualization of the element across the various phases. SBB coordinated this architectural information with the co-creators, and it formed the basis of the construction process.

To ensure comprehensive coordination among all parties, Boltt created digital mock-ups of various building components, focusing on the quality of the model, the architectural elements, and the BIM data. To optimize the construction process, the model was developed in alignment with the construction schedule. The longer the lead time for a building component, the earlier it was incorporated into the BIM model. This process was made possible through close consultation and collaboration with SBB.

During the later design phases, we worked closely with the contractor J.P. van Eesteren on this. Our technical designers developed a smart and practical construction method to maintain the pace of construction, ensuring that the client could begin leasing on schedule while preserving Studio Gang’s architectural design.

In a building this tall, a lot of technical infrastructure converges on the lower floors—precisely where you want to maintain an open feel. That’s why we put extra effort into the technical design of the areas where the ventilation ducts and sewer lines needed to be installed. We managed to conceal them in designated zones so that the double-height commercial spaces remained visually appealing.

Due to the limited construction site space and the short construction period of just 1.5 years for a gross floor area of 12,000 m², contractor Van Wijnen sought an extremely detailed BIM model that was perfectly aligned with the work of consultants and suppliers. Prefabrication and direct assembly of components straight from the truck were necessary to shorten the construction time and minimize construction errors. The BIM model also had to be suitable for checking the production models of the co-makers.

In the BIM model, the various building components—such as natural stone, window frames, structural elements, and steel structures—were developed separately. We organized and coordinated clash detection sessions to ensure alignment with consultants and the contractor. The entire building was first constructed virtually (and completed!), taking into account the assembly sequence and construction logistics. And during the production and execution phases, Boltt checked the production models. All digitally, of course.

We advised Adyen to have the connection designed by an artist and to invite several artists to submit proposals. Amsterdam-based street artist Frankey presented the most compelling design. The environmental permit drawings were created by Boltt, and we advised Frankey on the presentations to the aesthetics committee and the materialization of the design. We handled the further technical development, including for contractor Van Wijnen.

The bridge's facade is made of Acrylic One, with the facade panels formed using composite materials in 3D-printed molds. The walkable glass floor spans from building to building. The lamppost, the balustrades, and the bolts are also 3D-printed.

Starting with the preliminary design, work was carried out as part of a construction team in collaboration with the contractor Heijmans Woningbouw. In addition to all design work and the technical development of the design, Boltt played a coordinating role in this process, during which Boltt also facilitated and directed the BIM process. The construction team met once a week in Rotterdam to consult quickly and make decisions. This ensured a lightning-fast yet meticulous process.

The detailing was developed in collaboration with Heijmans Woningbouw and its subcontractors. Because the subcontractors also contributed ideas and worked together as part of the construction team, the model and details took shape relatively early in the process. As a result, there were relatively few changes to incorporate later on. This led us to ask: can we start manufacturing the prefabricated structural elements as early as the design phase? In short, how can we work through the process together as efficiently as possible?

Drawing on our knowledge of local construction practices and our background as designers, we assisted Studio Libeskind with the technical development and construction of this monument. The monument’s eventual completion was preceded by a complex process that spanned five years. Every change or addition—from extra names to lamps and fences—and every minor obstacle along the way was immediately incorporated into the model.

By providing 3D models and detailed drawings, we were able to illustrate the implications for all external consultants involved. Since the focus had to remain entirely on the monument, all necessary but distracting technical elements had to be subtly concealed. Throughout the process, we worked closely with Studio Libeskind to find the best solution in every instance.

We were in weekly contact with Studio Libeskind to ensure that we stayed as close as possible to the essence of the design. Boltt wanted to know exactly which design aspects were important so that proposed changes that did not meet these criteria could be rejected by the project team right away, allowing us to quickly seek a better solution. The time difference between New York and Amsterdam worked in our favor; issues raised in the afternoon often received a response the very next day—Dutch time.

The structural engineer’s archive drawings served as the starting point for modeling the building, and contractor BAM was involved at an early stage in creating 3D as-built surveys and point clouds. This allowed us to verify whether the elevation values in the point clouds matched those in the archive drawings. Cross-sections of the point clouds revealed the building’s tilt and whether any components were out of plumb.

To get a detailed view of the building’s condition, we used detailed drone photos of the entire exterior. By comparing these with historical imagery and archival drawings, we were able to determine which parts were historic and which were not. For example, this allowed us to conclude that a section of the first floor could be demolished. Using the historical imagery, we were able to identify elements that were not shown in the drawings and elements that had been replaced over time. One example of this is the steel windows with opening sections, which have been reintroduced in the new design.

BIM was actively used as a communication tool between the contractor, architect, structural engineer, and subcontractor. Using the ArchiCAD renovation filter, we were able to clearly visualize the existing, the elements to be demolished, and the new elements in the 3D model. This also applies to the load-bearing and non-load-bearing components, material properties, interior and exterior elements, and the NL/SfB codes. In addition, the steel supplier used the model as a basis for sizing their components.