This mega project, like others of its size, required strategic planning of BIM development processes to achieve the best possible outcome with limited budget and time constraints. Innovative solutions needed to be developed to optimise major BIM tasks without compromising the model quality, and to adhere to the tough healthcare codes and standards.
Developing multiple electrical trade BIM models for the 210,000sqm healthcare facility with capacity for 548 beds and 1,170 parking spaces required maximising the prefabrication of electrical raceways, wall rough-in boxes and other electrical modules to reduce site manpower needed and to accelerate the electrical installation of the prefabricated components.
Another major challenge is the model coordination. Electrical equipment needed to be coordinated in the very limited-spaced electrical rooms, as well as coordinating the electrical raceways and bus-ducts through congested mechanical ducts and fire protection pipes and sprinklers. Systematic and detailed clash detection techniques were needed to detect and resolve clashes between different trades. Furthermore, Engineering alternatives needed to be proposed to resolve clashes where coordination only could not clear the clashes.
During the design and construction of the project, a steady and ongoing stream of design changes was being received from consultants and other trades. This introduced the need to develop a flexible approach for design updating which ensures timely adapting our model with the design changes received with minimal or no impact on budget and schedule.
Major BIM activities that have statistically consumed significant working hours in previous projects with similar nature and size have been identified. The wiring of power systems - for example - consumes 30-40% of the power layouts development hours due to the need to comply with the applicable codes and standards for wire sizing, voltage drop, derating factors, etc. A Revit add-in was developed to populate the wiring information using the existing device information in the electrical consultant models. The tool calculates the wire size, voltage drop, derating factors in addition to other project specific requirements based on the load and rating of the devices. It also verifies conduit fills based on the wire sizes detected and suggests the optimal conduit size for all the conduits within the network.
The development of wall rough-ins layouts is another BIM activity that consumes significant BIM hours. An in-house tool was developed to detect the appropriate wall box for each device and place the wall box element aligned to the wall with correct elevation and populated wall box information.
Detailed prefabrication Revit families, assemblies and sheets were developed for various electrical assemblies such as high-level wall boxes, wall rough-in boxes and fire alarm modules. The bills of quantity for these prefabricated assemblies are being developed using Revit schedules.
A well-defined process was developed for asset information management. Various tools were developed to populate and verify asset information prior to extracting the COBie files and uploading them to the commissioning platform.
