BIM: Proving Its Value

Switch Engineering was engaged to design a conversion of an old air-side warehouse space into a 3,700 square foot walk-in cooler for food cargo at the Edmonton International Airport. At the beginning of this project, we chose to invest in a 3D point cloud, using a FARO Focus laser scanner, of the warehouse space. Each scan takes approximately 8 minutes to complete, and for this particular space, the scan took most of the day. This gave us a point cloud model of the pre-construction space with accuracy of measurements to +/- 1.00 mm.

 

Comparison to Point Cloud & Image

 

Initially, the design called for building the cooler interior to the space, including structural steel to support the cooler roof (made from insulated cooler panels). The cost for the structural steel exceeded the budget; therefore, the client needed a different option. Switch Engineering suggested coating the existing warehouse's interior with four to five inches of spray foam insulation. This alternative took away the need for internal structures and increased the working area of the cooler. We needed to ensure that the existing steel structure and roof assembly could handle the new dead load of 4 inches of spray foam. One challenge of determining if the roof could accept the additional dead load was the lack of as-built data.

 

Our structural engineer needed to measure the open web steel joists' profile and reverse engineer the as-designed dead load. Typically in this situation, a site visit would be required by the engineer, a lift rented, safety protocols followed, and hand measurements taken along the length of the steel member. This time spent coupled with the equipment rental would be thousands of dollars extra that the client would have to pay. Additionally, tape measures have an accuracy of +/- 4.00 mm at 8-meter measurements depending on their class, and there is an additional chance of human error. However, we had our point cloud ready for use. The Structural Engineer was able to create the open web steel joist profile, and as an additional benefit, see the bending profile of the joists under load allowing him to determine that the roof was not overloaded in the past. This was all done remotely using the point cloud we generated.

 

Measurements From the Point Cloud

 

In addition to significantly reducing the need for site visits for design verification, this point cloud scanner allows us to generate a very accurate BIM Revit model of the space to create drawings from and integrate with the client's asset management systems. For this cooler, we entered all model information of mechanical cooling equipment used here and directly integrated it into the client's asset management system format. This is an especially valuable takeaway for clients in situations like this where a retrofit project is on an old building with minimal to no as-built documentation.

 

We want to bring this value to all of our future retrofit projects and clients from this positive experience! And is the reason why Switch Engineering uses BIM in our work processes as a standard and not as an additional service.

 

Point Cloud in Revit