Construction general contractor
Beyond Clash Detection: How General Contractors Can Use BIM on Any Project
Kate Kirwan
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Construction general contractor

BIM (Building Information Modeling) has been a buzzword in the AEC industry for years—and yet the construction industry as a whole has been slow to adopt the BIM process. In this article, we will investigate the software and processes used by a single construction company to deliver powerful services to our owners, consultant teams, and trade partners. Learn how to integrate technologies such as 4D scheduling/animations, 3D laser scanning, virtual reality mockups, and 360-degree cameras into your projects—improving overall communication and coordination. This article will discuss Revit software, ReCap software, Navisworks software, and Autodesk Rendering, with examples of projects that used virtual design from start to finish, as well as projects that benefited from BIM in select areas of the project. It will summarize a construction company’s BIM journey from BIM-free to BIM as often as possible, on all stages of a project.

Definitions

Below are our definitions of BIM and Virtual Design and Construction (VDC). These definitions are key to the approach and methodology we use in Canadian Turner Construction Company.

Building Information Modeling (BIM)

We define the Building Information Model as the model of an individual system, be it architectural, structural, mechanical, electrical, plumbing, or fire protection.

Virtual Design and Construction (VDC)

Virtual Design and Construction is the process of managing all the individual 3D project models, or BIM, for the entire lifecycle of the project. This includes the very initial planning stages through to project completion and building management.

Current State: The US Versus Canada

Canada is behind many parts of the US in terms of the application of BIM and VDC. In my opinion, this is due in no small part to the refusal by the Canadian government to require building information modeling on public projects. This is applied in the interest of fairness, allowing companies who may not have the resources to invest in and implement BIM. However, in many cases, and again in my personal opinion; this is redundant as many smaller or less financially able companies do not have the resources to work on large-scale government projects and so will most often not be involved in projects where BIM is of major benefit to the project.

Whatever the reason for the difference in BIM provision between the two countries, it is a reality that often on projects in Canada, we receive 2D AutoCAD drawings only, particularly from the mechanical, electrical, plumbing and fire protection (MEPF) sectors. It is also a reality that often our trade partners will not provide models or drawings in any capacity, and that the consultants only will provide these services, although this is more prevalent on the West Coast of the country than the East.

This lack of BIM provision informs the way we approach our projects, and the VDC services we offer in the Canadian market.

Our Software Toolkit

The following software programs are part of our standard toolkit at Canadian Turner Construction Company. We have built up this library over the past few years with testing and as project need arises.

• Autodesk AutoCAD
• SketchUp
• Autodesk Revit
• Autodesk 360
• Autodesk Rendering
• Autodesk Navisworks
• Various plug-ins, such as iConstruct for Navisworks
• Adobe Design Suite
• Autodesk ReCap Pro
• Synchro Software
• Lumion
• HoloBuilder
• IrisVR
• InsiteVR
• Trimble RealWorks

Identify Technologies and Processes That Will Best Benefit Individual Projects

Know your audience. What are you trying to convey? What are you trying to achieve with your drawings and models?

Establishing the project requirements early on in the project is key to successfully implementing the VDC process. When we review the VDC implementation plan for our projects, we identify the target audience of the work we are required to provide. The technology and software we employ depends on the construction knowledge and technological capabilities of our audience.

For example, our clients generally do not have a good working knowledge of 2D drawings. We can lose sight of this, having read complex 2D drawings for many years on a daily basis. The images below illustrate the power of 3D models, and how complex information can instantly become easier to understand and more relatable in a 3D context. Figure 1 below is a 2D site logistics plan, outlining the planned crane swing impact, access roads for site works and deliveries, planned site trailer locations and man hoist requirements. While the 2D image could be enhanced with the addition of text and arrows outlining the various components, it is not an image that clearly conveys the magnitude of the site works, particularly to someone who is not used to reviewing drawings from a two-dimensional point of view. Figure 2 is the exact same image, taken from a 3D perspective. The viewer can now appreciate the scale of the construction site in context with the surrounding area.

2D site logistics plan
Figure 1. 2D site logistics plan. (Photo credit: Turner Construction)

 

3D view of the same model shown in the logistics plan above
Figure 2. 3D view of the same model shown in the logistics plan above. (Photo credit: Turner Construction)

How much time and how many resources do you have?

Another consideration when determining what technology should be applied to a project is the amount of time you have to complete the work. Having a fully coordinated model for a project is wonderfulunless the construction schedule is so tight that you don’t have the resources and information required to get the model ready at such a time when the information is actually of use for the project. In this area, communication is key. Time also dictates the quality of the work output. Consider the two screenshots on the following pages, Figures 3 and 4, taken from two different animations created for project pursuits.

Figure 3 is an image taken from an animation created using scenes in SketchUp. For this hospital project, the VDC Department was asked to produce an animation of one of the project’s eighteen construction phases. This animation had to demonstrate to the client the impact of construction on the main entrance to the hospital and convey our understanding regarding maintaining patient, emergency vehicle, staff and visitor access during the course of construction. We only had three days to produce the model, one VDC modeler available to do the work, and they were located on the other side of the country in relation to the project. An added complication was that the project drawings, which were only provided in PDF at that stage, related to the interior works and only showed the outline of the exterior of the building. There were no exterior elevations. How were we going to model the exterior of a building from the other side of the country in three days?

The answer was Google Earth. The modeler “walked” up and down the street from the comfort of their desk, modeled the surrounding area and matched materials from the building as per the Google Earth images.

The resulting model allowed us to provide a rudimentary, albeit recognizable, animation showing the maintenance of building access, emergency service parking and patient drop-off zones, along with our hoarding plan and clear way finding signage. The client was able to recognize their building, and better able to understand our plan than if we had put marked-up 2D drawings in front of them. After we won the project, the hospital representatives asked us to create more models as construction progressed. We produced multiple interior animation videos demonstrating the impact of construction on the day-to-day operations of the hospital.

SketchUp animation screenshot
Figure 3. Time consideration: SketchUp animation screenshot. (Photo credit: Turner Construction)

Figure 4 is an image taken from a pursuit model created using Revit and SketchUp models which were imported into Lumion. Additional Lumion elements were added, scenes were created and the animation was rendered in the program. The VDC team had eight days to produce this model, with two staff members assigned. The project drawings were available in PDF only, but with more manpower and more time, we were able to produce a more detailed animation with a higher graphical standard.

Time consideration: Lumion animation shot
Figure 4. Time consideration: Lumion animation shot. (Photo credit: Turner Construction)

What resources do you have?

The final consideration, and perhaps the most important one, is the budget available to complete the work. This budget incorporates not just the software used, but also any training required and the time required to complete the work, as per Figure 5.

VDC department budget
Figure 5. VDC Department budget. (Photo credit: Turner Construction)

What can you do with the software you currently have access to, and will it provide what you need for the project? Turner’s Software toolkit, as shown above, contains 15 different programs, with an estimated cost per annum of $11,500 per person for our four person team. Bear in mind that this cost does not repeat in full on an annual basisprograms like Lumion and Trimble RealWorks are a one-off cost unless upgrading a newer version. The calculation in Figure 5 also divides the cost of a single or shared license into four, to account for our team.

Figure 3, the image from the hospital project animation video, was created by one modeler in three days with SketchUp, an inexpensive program, and Google Earth, which is free. The animation shown in Figure 4 took two modelers eight days to create, using Revit, SketchUp, and Lumion software. It also required a high-powered laptop with an excellent graphics card to create a top-quality animation. Not only are you paying for the software and the laptop, you have to factor in 128 hours of salary paid to the two modelers. All of these factors are important to consider when deciding what to integrate into your construction projects.

Technologies That Can Be Integrated into Construction Projects

There are a number of technologies that can be incorporated into the construction process. This section will focus on the most common technologies we integrate into our projects3D laser scanners, 360-degree cameras and virtual reality models. We provide all these services in-house rather than outsourcing, which allows us to control the final product, and quickly make changes if requested.

3D Laser Scanning

3D laser scanning is a non-contact, non-destructible technology that captures a physical object’s exact size and shape in the form of a digital 3D representation. There are three types of laser scanners: short range, mid-range, and long range. Short range scanners are typically less accurate than mid- to long-range scanners as they use laser triangulation rather than the pulse-based or time of flight method of medium to long range models. Laser scanners are based on the speed of light conceptif the length of time a laser takes to reach an object and reflect back to the sensor is known, then the distance of the object from the scanner can be calculated.

Each scanner model will specify their maximum range, or scan density, however it is imperative not to rely on the extents of these boundaries for accurate data capture as the further the distance, the less accurate a scan will be. Typical scan settings for a large area are set to a point density of 3 mm at 10 meters. This means there is a point spacing of 3 mm between each point at a distance of 10 meters. When the scanner is moved outside the 10-meter range, the distance between each point increases, so that at 20 meters the distance between each point is 6 mm. The lower the point density, the less detailed a scan will be.

It is important to remember that 3D laser scans can only see what the naked eye can seethey cannot X-ray or see through anything! Generally, multiple scans are necessary to capture all the data required. These scans must be pre-aligned in a common frame (either manually or with the laser scanners’ inclinometer) and overlap one another. The scans must be “stitched together” or registered later to create a comprehensive point cloud of the entire project. To facilitate this registration, targets, spheres or a mixture of the two are used in the field. A minimum of three common targets or spheres are required between adjacent scans. I like to have at least five common points to guarantee I can properly align the scans with one another.

Spheres and targets used to combine multiple scans together accurately
Figure 6. Spheres and targets, used to combine multiple scans together accurately. (Photo credit: Turner Construction)

We first used 3D laser scanning on a law firm project in downtown Vancouver. This project was a tenant improvement project, within a seven-story building dating back to 1973. The building was completely stripped back to original structure and split into a number of unitsa Nordstrom department store, offices for Microsoft and Sony ImageWorks, and the 40,000 square foot Miller Thompson law firm office on the 4th floor. We received base building AutoCAD files from the landlord, and the project interior designers created a Revit model based on the information contained within these files. The designers requested some dimensions from site, and the project coordinator and I went to take these measurements. We quickly realized that there were major discrepancies between the as built drawings provided by the landlord and the actual conditions on site.

We had access to the site a couple of months before construction began, which really helped as there was only one person available at the time to do all the scan-to-BIM work. We persuaded the owner to pay for the scanning, and using a Faro X330 3D laser scanner we completed 268 full color scans in the space of seven days. It took three weeks total to combine these scans in Autodesk ReCap Pro, bring them into Revit and model the existing conditions. Figure 7 below outlines the scan-to-BIM process. The completed 3D model revealed information critical to the success of the project; the perfectly aligned, 30-inch diameter columns shown on the base building drawings actually ranged in size from 26.5 inches to 31.5 inches in diameter, and they certainly were not in a straight line. This knowledge saved a lot of time and rework for the project, as there was custom pre-manufactured planters and seating wrapping around these columns. The large duct shown in Figure 7 was undocumented, and went straight through the planned mezzanine loft space. We decided to relocate the loft rather than reroute the mechanical system. Raised access flooring was specified across half the area of the office space, and we discovered that the height of this raised access flooring conflicted in parts with the perimeter ventilation boxes used for heating and cooling. Customized office pods imported from Italy had strict tolerances with regard to floor flatness, and our floor wasn’t flat! By using Trimble RealWorks, we were able to analyze the floor “levelness” and resolve any issues weeks before the system arrived from Europe.

Scan-to-BIM process
Figure 7. Scan-to-BIM process. Top left: site photo; top right: combined 3D laser scans. Bottom left: modeling process; bottom right: the completed model. (Photo credit: Turner Construction)

The exterior walls of the office space were made up of a glazed curtain wall system. When we initially modeled from the 3D laser scans, we didn’t model the curtain walls. However, when our drywall trade partners began to lay out their wall locations on site, we realized that the meeting room walls, laid out along the perimeter of the office, were defined by the window mullion locations. These locations were based on the landlord’s drawings. As a result, every single perimeter wall location had to be revised. Rather than having the site team work to figure out a layout, calculate the new volume of each room and quantify the change required to the interior designer, we were able to go back to our original scans. An exercise that would have taken a couple of days to figure out on site only took a few hours to resolve. We modeled the actual window mullion locations, laid out the new wall locations, and created drawings for approval by the design team within a four-hour time frame.

Since this first project, we have completed the scan-to-BIM process in-house on a number of different projects across Canada. We began with renting our scanners from a third party, and in February 2018 purchased a Leica BLK 360 scanner. Depending on the project requirements, we use Faro total station scanners or our BLK 360 unit to complete the scans.

Floor flatness or "levelness" study
Figure 8. Floor flatness or "levelness" study. (Photo credit: Turner Construction)

360-Degree Cameras

360-degree cameras are omnidirectional cameras with a 360-degree field of view. Essentially, a view in every direction is recorded within a single image. At Turner Construction, we use 360-degree cameras for numerous reasonsto document construction progress for our owners, to capture existing conditions and to create a digital portfolio of our work.

We take 360-degree images with either our Samsung Gear 360 camera or our Ricoh Theta V camera and upload them to HoloBuilder, a cloud-based software that allows us to create virtual tours of our sites. We use HoloBuilder because it is easy to share the images and easy for the end user to navigate.

Virtual Reality (VR)

Virtual reality is a computer-generated immersive experience within a 3D environment. A person using virtual reality equipment is able to "look around" the artificial world, move around in it, and interact with virtual features or items. We share out VR models across a number of different platforms, and we create all our VR models in house using a number of different software programs.

As shown in Figures 1 and 2, complex information can instantly become easier to understand and more relatable in a 3D context versus a 2D one. We create and use virtual reality models to deepen understanding of a particular project element, such as a virtual model of kitchen millwork, for example; or deepen understanding of a project space, such as the layout of the entire kitchen.

The Watson Goepel law firm project is one such example. This tenant improvement, or fit out, project is located in downtown Vancouver, and a team of nine partners from the firm formed a steering committee in charge of approving the design decisions. The interior design team created beautiful, detailed look books for the project to complement their 2D AutoCAD drawings, but given that the lawyers were unused to reading 2D drawings, they were having trouble visualizing the space. This was causing delays to our construction schedule.

To help the client understand the design and expedite their decisions, we decided to model key areas of the project. These areas included the reception area, the client kitchen, main boardroom, private offices and interstitial meeting rooms and one of the open office areas. We worked closely with the interior designer, who provided all information relating to the textures and finishes of the office, and created incredibly detailed Revit models. Using the exact material specifications from websites and catalogs, we produced custom families of every single component in the chosen areas; manipulating images of the finishes in PhotoShop to produce seamless textures. We rendered the models in the cloud with Autodesk Rendering.

When we shared the VR models with the steering committee, they were immediately able to understand their new office. They signed off on a particularly expensive piece of millwork in the client kitchen that had been holding up construction, changed the height of cabinets in the open office from 6 feet high to 4 feet high to maintain clear lines of sight, and changed the custom-designed reception desk from round to rectangular.

Evolution of the reception desk at Watson Goepel
Figure 9. Evolution of the reception desk at Watson Goepel. (Photo credit: Turner Construction)

 

Companion Class

BIM (Building Information Modeling) has been a buzzword in the architecture, engineering, and construction industry for years—and yet the construction industry as a whole has been slow to adopt the BIM process. In this session, we will investigate the software and processes used by a single construction company to deliver powerful services to our owners, consultant teams, and trade partners. Learn how to integrate technologies such as 4D scheduling/animations, 3D laser scanning, virtual reality...
Industry Talk
Autodesk University
Beyond Clash Detection: How General Contractors Can Use BIM on Any Project

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