How BIM and modular construction can help reduce construction waste
The US Environmental Protection Agency (EPA) reported that 145 million tons of construction and demolition waste were dumped in the US landfills in 2018. Besides, the construction industry is responsible for 39% of global carbon emissions. By 2025, the annual construction waste is expected to reach 2.2 billion tons globally. So how do we tackle this inevitable crisis that stems from unmanaged construction waste?
A possible measure is to use innovative solutions like Building Information Model (BIM), and prefabrication and modular construction across small-and-large scale projects. Modular prefabricated construction means constructing components of the building structure off-site and later transporting these components to the construction site for assembly. For example, the floors, walls and panels are constructed off-site and later installed together at the construction site.
Prefabrication and modular construction have been a great boon to the US AEC industry. The COVID crisis has pushed the industry to adopt technology that can help us overcome manpower shortage, construction costs and supply-chain issues in construction. Together with 3D BIM models, modular construction can ensure shorter project duration, enhanced resource management, better product quality and more importantly reduced construction waste. Let’s find out how:
? When it comes to prefabrication, the off-site construction and the use of technologies such as 3D printing require fewer materials and yet deliver better quality. The left-over material, if any, is reused in-house thus avoiding construction waste dumped in landfills.
? Building Information Modeling or BIM helps designers and other construction stakeholders visualize and gauge the dimensions and location of prefabricated components. The digital construction allows the project team members to estimate the quantity and location of the components and help them decide elements that require prefabrication.
? The design stage becomes easier with precise calculations of building elements and area measurements. Besides, this detailed information assists project stakeholders in identifying the number of resources required for the project. This, in turn, decreases construction waste.
For example, structural steel, metal studs and electrical panel with pre-cut wires as per required length, roofing with panels, ceiling light with the prewired metal jacket are some of the building elements that can be prefabricated off-site as per the design requirement.
Here’s a case study of an apartment building built using BIM and modular construction that will help us see this in application. Can we mention the case study as a reference?
The apartment building has a combination of metal and brick panel facades. It has five levels of apartments with wooden frames and two levels of concrete retail/office/common spaces and one-level underground parking. The entire project spans across an area of 2,41,070 square feet including the underground parking.
The BIM implementation plan was for the architectural design. Vertical framing had standard dimensions (8 feet). Frames around the windows had standardized dimensions as well. As a result, the studs were ordered as per the required length and even the dry wall had a standard size.
With the help of BIM, the electrical contractor retrieved information on wire length for each outlet. The electrical break panels, could therefore be, delivered directly on-site with connected wires. On-site, the contractor had to simply use the wire to the outlet. Also, the electrical metal cladding was pre-cut off-site. This avoided the use of excess wiring and metal cladding.
Similarly, in the case of plumbing, elbows fitting, spools cutting and other waste line PVC related jobs were prefabricated at the plumbing contractor’s shop. The plumbing parts were later fixed together on-site. With this off-site prefabrication, it was possible to cut most spools out of the same 20-feet piping material, thus saving piping materials.
The BIM coordination, construction planning, use of prefabricated framings, electrical and plumbing works helped in reducing on-site construction waste. Besides, the use of standardized dimensions and cutting construction materials at the shop lowered the number of packing materials that were brought to the construction site. Prefabrication jobs also led to less waste at the construction site and thus required fewer laborers to remove the waste and fewer dump trucks to dispose of the waste.
To sum it up, we cannot avoid construction waste. However, we can reduce construction waste by the efficient use of innovative technologies. BIM and modular construction technologies not only speed up the building process, help save time and costs, but also lower the environmental impact. This only makes it a win-win situation for all of us in the construction industry!