By Ernest Granson
We all know what a construction site looks like: a huge hole in the ground with a lot of construction workers clambering over concrete pads, setting up scaffolding, wiring together rebar, framing walls, installing drywall and more. But the days of the project manager and the architect examining a blueprint on the hood of a pickup truck at a construction site are gradually fading, being replaced by field accessible Internet, laptops and tablets and advanced integrated software.
That’s not to say the very physical component of construction has disappeared. The building still has to be put together by those concrete and steel workers as well as all the other trades workers. But even those trades – drywallers, plumbers, electricians and sheet metal workers – are wired into networks that significantly increase the cost efficiency, decrease the build time and create a comprehensive and immediate accessible records system. And while those benefits are certainly welcome from a business aspect, there’s another key element to consider and that is the potential for better building techniques to help reduce the housing shortage.
Just what are those better building techniques? And what makes them superior to traditional methods? Well, that technology is called Building Information Modelling or BIM. In very basic terms, it amounts to data collection and, most importantly, centralization of that data. Thus, you have the technology which collects the data and the software which merges the data for access by everyone involved in the project. This combination enables multiple functions that all groups can utilize in real time. What BIM really stands for is a model of a building with information embedded into it.
For Bird Construction Inc., one of the largest and oldest construction companies in Canada, Digital Construction helps to shorten construction time on projects, reduces wastage, and increases the efficiency of its staff members and crews. Significantly says Kashish Madaan, Bird’s Lead of Digital Construction for Southern Alberta and Interior BC, BIM helps to pinpoint issues before they become problems on site during construction and that, in turn, reduces overall construction costs. But just how much cost and how much time can BIM save for a particular project?
“That’s a challenging question to answer,” Madaan explains. “The savings vary with project complexity—more complex projects tend to benefit more from BIM. Other factors include the quality of the design model, enhanced collaboration and communication for faster problem-solving, and quick decision-making facilitated by the information available through BIM."
To put that into perspective, let’s take a look at how BIM differs from traditional design modelling. That means we go way back to 1842 when chemist, astronomer and photographer John Herschel discovered that handmade drawings could be reproduced by laying a translucent or semi-transparent drawing on a chemically coated paper, then exposing it to ultraviolet light. The exposed parts of the drawing turned blue while the lines, which blocked out the light, remained white. This process could then be used to inexpensively reproduce as many drawings as necessary. In the 1940s, diazo blueline prints, which involved fewer toxic chemicals, began to take the place of blueprints. As you might guess, the blue-line process resulted in blue lines on a white background. In the late 1990s, both of those reproduction methods were replaced by large-scale scanners and printers and then by AutoCAD or Computer-Aided Design systems.
But, as Madaan points out, even those CAD-produced drawings were limited to a 2-dimensional flat surface. “When those plans were drawn, they were simply lines,” he says. “But now, with BIM, what it means is that each line you see on a blueprint represents something. When you open a Revit model file on your computer and select a line within the drawing, it displays the properties assigned to that line or group of lines. These properties indicate whether it represents a wall, plumbing pipe, or another type of element. This feature provides all relevant information upfront, including attributes such as wall length, width, and area, which are automatically populated through the Revit design software
Kashish Madaan, Lead - Digital Construction (Southern Alberta and Interior BC) at Bird Construction (right) and Shahin Mohamed, Digital Construction Coordinator (left), examine a DJI Mavic 3E drone which has just set down after its autonomous flight path over the construction site at SAIT's Taylor Family Campus Centre Redevelopment Project. After capturing images of the construction site the images will be uploaded to the DroneDeploy software for processing into a 3D map of the site.
“For another example,” says Madaan, “let’s say the architect wants to initiate an energy consumption analysis. That analysis can be based on the information which has been assigned to specific objects in the model. If the model shows that windows are facing southwest and the building is receiving a lot of sunshine it means there will be less energy needed to heat up the building. Now we’re saving on energy consumption. If the windows are facing north or east or the east and just getting sunlight during the morning, more energy must be utilized to heat up that space in the evening. So, during the design phase, all of this information can be used to make our project more sustainable and efficient.”
Functions such as energy analysis are enabled when the architect enters project coordinates into the software so that the building becomes located in real space and in real time. Usually, those coordinates are based on survey points or GPS location. From there, the architect can begin to develop the design. Once the initial model is built with the relevant metadata added to the model elements, the design can be visualized in 3D, which leads to the next step - clash detection. Clash detection is essential to identify any conflicts, especially in huge projects with a massive design and the vast number of components such as plumbing pipes, supplier ducts, return air ducts, fire prediction pipes, electrical wiring and conduits, electrical cable trays and many more. The traditional process would be for each of the various contractors and consultants to provide their own set of drawings to the building contractor with the assumption that all of the elements would fit without conflict. Then the process would see each of the subcontractors install their components; the electric trades would install their wiring and cable trays; the plumbing would go in, and so on. Inevitably, some of those components would find themselves fighting for space since the plans for each subcontractor had been designed independently. To resolve this, some components would have to be removed and then reinstalled. The result was a lot of rework, a lot of wastage and more time spent on construction.
“In today’s world,” Madaan explains, “all of this information is readily available prior to actual construction through BIM. The subcontractors submit their sets of models to us as they are developing them and they are collaborated into one platform in which we run the clash tests. If I know there is a certain space into which services are not fitting, we might have a conversation with the architect to maybe lower the ceiling a bit. The important thing is, we are having those conversations even before construction begins”
While BIM is primarily used to create the 3D models that encompass the geometry, spatial relationships, and data associated with building components, VDC or virtual design and construction software, is an integrated approach that combines BIM with project management techniques to optimize the construction process.
It focuses on the planning, coordination, and execution of construction activities. VDC tools such as Revit, Navisworks, Autodesk Assemble, Fuzor, Synchro and many more allow the contractor to estimate cost and quantities, as well as construction scheduling. By marrying BIM and VDC, the contractor is able to visualize a schedule and determine issues before construction starts. Some VDC platforms also incorporate pricing for labor, equipment and even for cost of living, politics and geography.
As far as accuracy of those functions – information populated into the BIM model, scheduling and cost estimates – Madaan says it’s dependent upon the accuracy of information entered by the various teams involved in the project.
The on-site reality show
There’s another vital component which the construction industry has adopted to achieve even more cost efficiency and that is what Madaan calls reality capture. By harnessing mobile technology, contractors are able to accurately monitor construction progress, not only to make sure the project is on schedule but also to track material usage and cost, again, all in realtime. This component is usually divided into zones; drones, laser scanners and 360-degree cameras.
A drone’s primary mission is to create a 3D map of the construction site. It flies autonomously over the site, captures the data and flies back to the on-site operator. For the most part, the data is in the form of images, but the payloads on the drone can vary. For instance, it could be outfitted with a laser scanner camera for various measurement functions or with a thermal camera which can estimate heat loss.
Back at the office, Madaan says he uploads the set of images onto the DroneDeploy program. “It takes about three to four hours to process the data. Once it’s processed it creates the 3D topography,” Madaan says. “A typical schedule would see the drone complete one flight on a Monday and then again later in the week. I can then compare the data for the two flights and it tells me how much earth has been moved. If the excavator contractor is billing me weekly, I can confirm the volume of earth moved and approve the bill. A bird’s eye view of the site, helps us plan our logistics as well.”
The drone can determine elevation points to assess not only the site’s topography but also boundaries and flood risk, information that is essential for issues like insurance premiums and legal disputes.
Laser scanning or HDS (high-definition surveying) has become another important tool to increase construction efficiency and safety.
Although the technology has been around since the 1960s, it wasn’t until recently, when bandwidth and data storage costs became economically feasible, that the construction sector has been able to utilize it consistently.
In very basic terms, a laser scanner captures the shape and geometry of objects and creates 3D models which can then be integrated with BIM and/or VDC to produce accurate visualization of a building project including the architectural frameworks and the various utility or mechanical components such as ductwork. Measurements of structures by a scanner can be as precise as a millimeter and can capture millions of data points per second so a technician using a single handheld scanner can complete the measurement of project in a fraction of the time that it would take a team of workers over a period of days. And, because the scanner is able to measure high ceilings from the ground or penetrate into inaccessible areas it can eliminate safety hazards.
Once the data, called the “point cloud” is gathered, it’s uploaded to create a database of connecting points in a 3D co-ordinate system. The resulting 3D models are then accessible to any personnel or teams of personnel anywhere in the world, reducing or even eliminating the necessity for site visits.
Working in conjunction with laser scanning is the use of 360- degree cameras mounted on hard hats that document progress on the job site. As Madaan explains, there is no extra work or stoppage involved for a project coordinator or site foreman who simply walks through the site as they would on a normal inspection. Recording of the 360-degree camera coverage is uploaded to the server and is available for viewing by everyone associated with the project. Progress can be monitored by viewing the day’s inspection and comparing it to previous inspections. A time lapse sequence can also be created throughout all the phases of the project. Software such as OpenSpace Capture, which is one of the programs used by Bird Construction, tracks the location of the camera wearer on the site in relevance to the floor plans. This allows the viewer to know exactly where on the site the images/video are being captured. The viewer sees a view similar to Google Maps.
While this captured data is useful to follow construction progress, there’s another significant purpose and that is for providing evidence in case of a claim by one of the parties involved in the project. “Take for instance, a claim that this particular wall wasn’t installed correctly or something had been installed or left inside of a wall that shouldn’t have been,” Madaan says. “With time stamped images/video recordings, any of those claims can be confirmed.”
From blueprints to digital analysis
There are even more sophisticated software tools available that can boost efficiency for construction products as Madaan points out, software that Bird, in fact, is already using such as Revizto. This tool greatly adds a new dimension to project co-ordination and documentation. The Revizto app incorporates massive amounts of information about a project including all 2D drawings, 3D models and issue tracking that enables efficient communication between all project stakeholders. Bird Construction plans its construction logistics in a 3D environment. Site superintendents utilize VDC tools to visualize various scenarios, allowing them to address complex logistics issues before they become actual problems.
“To enhance progress tracking,” says Madaan, “our team conditions models to feed data directly into Microsoft Power BI. This enables the creation of customized progress tracking reports.
Traditionally, we would compile information manually in Excel or on paper. Now, this information is added directly as model attributes, streamlining the process and ensuring real-time updates in Power BI.”
For example, during a concrete pour, the foreman can enter the quantity of concrete in real-time using a tablet, along with relevant details such as the concrete grade and cost. This data is live-linked with a Power BI report, ensuring that everyone, including management, is instantly informed when the job is completed and aware of the associated numbers. There’s no need for manual calculations, which saves time and eliminates unnecessary update meetings. Equally important, this type of software serves as a data management and analytics tool, enhancing overall project efficiency.
It should also be pointed out that Artificial Intelligence has become a vital component of construction software. There are numerous apps such as Autodesk Construction Cloud, Procore, nPlan, Doxel and more which integrate AI for not just project management and analysis but for also for prediction of risk, potential delay and budget overruns. Just as in other industries, AI is considered a tool that will bring analysis, prediction and efficiency to a new level.
