Total BIM in a Complex Renovation

Despite significant uncertainty, unknown structures, and heritage constraints, the project was delivered as a Total BIM project, with the 3D model serving as the legal contractual document. The BIM model evolved in stages:

• Initial modeling from historic drawings,

• Progressive laser scanning as access became available,

• Continuous refinement during demolition and construction.

Laser scanning and tools like Imerso were used throughout the project to achieve high precision where needed (e.g., elevator shafts), uncover discrepancies between drawings and reality, and resolve risks early—avoiding production delays.

Digital Rebar Without Drawings

The core innovation was delivering rebar entirely through 3D models, without traditional rebar drawings. Together with the structural engineer and concrete subcontractor, the team defined exactly what site crews needed from the model. Custom property sets (psets) were created for rebar, allowing workers to filter by building part, sequence, size, and type directly on-site using StreamBIM.

Concrete work was organized into work orders (StreamBIM topics) tied to specific building parts. Each work order included:

• Filtered 3D geometry,

• Automated quantity take-offs,

• Rebar specifications,

• Progress photos, quality checklists, and concrete mix documentation.

When unexpected site conditions arose—common in renovations—questions and solutions were handled directly in the same topic, with engineers updating the model instead of issuing new drawings. Models were refreshed nightly, ensuring site teams always worked with current information.

Productivity, Safety, and Culture

Using StreamBIM on mobile devices significantly reduced administrative work for supervisors, allowing them to spend more time on-site supporting production. The project also introduced a “command center” at the site entrance, with screens showing safety issues via a traffic-light system. This improved awareness, collaboration, and overall site safety.

Results and Lessons Learned

The project was delivered on time, on budget, with a low carbon footprint, extensive reuse of materials, and significantly improved energy performance—despite strict façade preservation constraints. It won multiple Swedish awards, including Best Construction Project, Best On-site Safety, og Best Project Culture and Quality.

Key takeaways included:

• Break complex projects into small, buildable parts,

• Use BIM as a live production tool, not just documentation,

• Be cautious with prefabricated rebar in renovation projects—flexibility on-site is crucial.

  
  
  

Looking Ahead

Johannes concludes by briefly showcasing Byggstyrning’s latest StreamBIM add-ons, including real-world contextual visualization (e.g., views from future boardrooms using map data) and dashboards monitoring automated BIM-to-IFC-to-StreamBIM pipelines.

Overall, the presentation demonstrated how mindset, collaboration, and well-structured digital workflows can make fully model-based construction not only feasible, but highly effective—even in the most challenging renovation environments.