By Kevin Brooks, LEED AP BD+C
October 28, 2021
Hey everyone! If you’re anything like me you were pretty into Lego’s as a kid. I don’t know about you, but I much preferred building sets over making my own designs – probably why I study Civil Engineering rather than Architecture! Turns out, we’re not still too young to play with Legos – or at least we can use much more expensive ones now.
Modular construction is what happens when a kid who loves legos ages twenty years and gets told to construct a building, give or take a few extra steps.
Ok – jests aside, modular (also known as volumetric) construction is pretty cool, and I’m going to talk about how it works and how it can be more sustainable than the default construction practices.
Modular Construction – How does it work?
Modular construction is a new trend in construction where large portions of a building are fabricated off site in a factory-like setting, then brought to the construction site and assembled together. This is most powerful in residential construction settings, where one building may have hundreds of rooms, but only a few layouts for those rooms. A factory could be set up to mass produce these rooms.
Volumetric techniques aren’t exclusively used to make rooms. Prefabricated wall panels are becoming more common as well. Some projects have even prefabricated entire mechanical rooms!
Modules are assembled in a factory-like setting similar to an assembly line. All the usual trades on a construction site, like plumbers and electricians, participate in the process. The difference from a regular project is that instead of having to move throughout the building to complete their work, the pieces of the building they work on move to them. This helps laborers be more efficient, but also safer. Falling objects become a nonissue and hazardous work, like welding, can easily be conducted away from other workers, rather than relying on control measures like barricades to keep people away from danger. The risk of a fall is dramatically reduced as the furthest a person can fall is from the module under construction to the factory floor.
Quality control becomes much easier as well. Each time a trade finishes on a module, the work can be inspected and touched up where needed. This contradicts a normal construction site, where the pace of work means that areas often only get checked after many trades have finished their work in the area, and have already moved onto other parts of the building. While laborers are needed at the actual jobsite to connect all the modules together, the number needed is much lower than at a typical construction site. Similarly, management staff is mostly required at the factory. This keeps staff and workers, for the most part, out of the elements that a building can be subjected to before it’s airtight. The need for field offices is reduced as well, but even field offices can be made from modular components! Jobsite offices tend to not be very energy efficient, so relocating to a permanent factory office would allow for huge energy savings – and it’d just be more comfortable.
The Triple Bottom Line – What is it?
Also known as the three pillars of sustainability, the triple bottom line encapsulates the major points of sustainability.
People:
Humans lie at the center of sustainability. After all, we want to save the world because we would like to keep living in it. Sustainable development puts a priority on human health and comfort. This can be accomplished in many ways, such as engineering the acoustics of a building to minimize irritating noise, ensuring that paints don’t off-gas harmful chemicals, or providing sufficient glazing for occupants to see the outside world during their work days.
Planet:
Climate change and its effects on humanity are the driving factors behind sustainable development. Therefore, the world must be considered, not just the humans in it. So we must look at how the built environment affects the planet. Does the roof reflect the sun’s rays and stay cool? Or does it absorb them, contributing to the heat island effect? How much energy does the structure use? How much carbon did it create by being built? How much more will it generate over its lifetime?
Profit:
This last point is more to allow sustainability to fit within society. For years, politicians have debated whether regulations are fair or not, and it’s generally a common claim that sustainability and high quality can’t coexist with low costs.
Personally, I think that our system’s current focus on short-term profit doesn’t actually minimize net cost – it simply pushes it somewhere else, whether that’s onto another company, or a few years down the line. Take plastic. It’s cheap and easy to use, but someday, we’re going to have to figure out how to get rid of it before it chokes our oceans. Even some current trends in design fall prey to this. Instead of retrofitting buildings to make them more energy efficient, owners will decide to build more efficient energy generation, saving in the short term but neglecting to solve the issue requiring them to spend money in the first place.
LEED, WELL, LBC, and other sustainable design systems aim to change the belief on that. Energy efficient buildings cost less to operate, even if they cost a little more initially. By getting input from all stakeholders early in the design process, costly changes can be avoided down the line. More importantly, the quality of the building you’re in can psychologically affect you, and it’s been shown time and time again that happy people work better.
How does Volumetric Construction fit into the Triple Bottom Line?
There’s no quick answer to this question. Volumetric construction is like an early car in the era of horses – it could revolutionize the industry if it catches on.
Let’s go point-by-point here:
- People:
- Construction is a dangerous job. Laborers are exposed to heights, heat, cold, welding, falling objects, and more. While companies are working to be safer, it’s a difficult process. Many laborers are used to working under very lax safety conditions – I’ve stopped counting the number of times I round a corner to watch a worker put their hard hat back on. Even worse, the air quality systems designed to protect a building’s occupants often don’t get turned on until after construction finishes to keep them clean. But what about the workers?
- What if we could put construction in a climate-controlled environment? One with specific spots for welding? One where there’s no work going on ten stories above you, where a dropped hammer could end your life?
- We could have facilities that are cleaner and more comfortable. The noise of a construction site would be removed from a city and put into a factory setting where it’s more appropriate. The factory can also be designed with noise attenuation to protect workers’ hearing, and appropriate ventilation can be added.
- At present, workers have to carry tools, materials, and personal items between areas of the jobsite every day. They have ‘shacks’, or temporary rooms where they can put their stuff. If you’re someone who works throughout a building, your shack might be twenty floors below you.
- What if workers had a consistent place to put their belongings, to eat lunch, and rest, that was near their job? They didn’t have to run around the building or transport all their tools whenever they finished a task. No tools left lying around the jobsite either. Not only would this be easier, it’d be more efficient – less time spent finding lost drill batteries or tracking down carts, more time spent getting things done. And for those new to the field, more work means more experience.
- Construction jobs aren’t consistent. They’re hourly, which means overtime for those who want it, but they can come and go with the project for those lower on the ladder. The variability of jobsite locations also means that one day your commute might be fine, the next it’s tripled in length (realistically, traffic does this too).
- By moving to a factory, workers don’t have to swarm a jobsite and take up all nearby parking. They could park at a factory that’s more accessible, reducing traffic within the city and shortening their commutes, allowing them more time to enjoy their lives. It’d be safer (driving is dangerous), cut down on CO2 emissions, and everyone would be a lot happier.
- Construction is a dangerous job. Laborers are exposed to heights, heat, cold, welding, falling objects, and more. While companies are working to be safer, it’s a difficult process. Many laborers are used to working under very lax safety conditions – I’ve stopped counting the number of times I round a corner to watch a worker put their hard hat back on. Even worse, the air quality systems designed to protect a building’s occupants often don’t get turned on until after construction finishes to keep them clean. But what about the workers?
- Planet:
- Currently, materials for projects are delivered to the site and stored somewhere, requiring part of the building to be constructed before materials can be handled effectively. Procurement of materials is a logistical hassle and trucks go in and out of job sites all day bringing shipments. Further, great amounts of trash are created, being hauled away in dumpsters.
- By using a factory, materials can be delivered and stored in greater quantities, and the constraint of onsite storage being limited by other trades and project progress is greatly mitigated. It’s also possible for arrangements to be made with suppliers for bulk packaging that can be shipped back to the manufacturer, reducing the amount of waste that needs to be disposed of or recycled.
- Construction sites tend to be inefficient users of energy. Even on the most advanced structures, advancements in insulation and heating, lighting, and ventilation don’t do much for a building that has no exterior walls. When only the exterior walls are installed but the main heating or cooling systems aren’t running, you rely on temporary measures that tend to be less efficient. Field offices suffer from similar issues.
- Working within a factory means laborers can work in a building that is insulated, well-lit, and climate controlled using systems designed to serve the purpose, rather than temporary measures.
- Quality control on current job sites is difficult to maintain due to the pace of work and how spread out it is. Despite new systems such as BIM360 field which help with quality issue tracking, there’s more and more double entry and project staff get bogged down with how much ground they have to cover – it’s simply not possible to check every area every time a trade finishes work there.
- On an assembly line, each trade’s work could be checked for every module as they progress through the line. One supervisor could check every module without having to walk through the entire building multiple times a day, just observing them as they roll by.
- This has major implications for sustainability. Building systems only function as designed if they’re installed as designed. By improving quality control, systems work and function better, meaning the buildings will perform closer to their design levels. Higher quality installations means fewer leaky pipes, poorly sealed vents, and malfunctioning heaters, all of which waste energy and water.
- Currently, buildings are designed to be hard to bring down – makes sense in terms of keeping them standing. But when it comes time for them to be demolished, they often have to be blasted apart with explosives or broken up with kinetic methods.This damages many of the core components of the building and makes them non reusable.
- With some effort, modular buildings can be taken apart in a similar fashion to how they were put up. This can make material reclamation and recycling much easier. Further, it’s easier to renovate a modular building as the modules can simply be removed and reorganized to rotate them around the structure while taking selected ones off site to be repaired.Theoretically, factories similar to the ones used to assemble modular buildings could be used to disassemble the modules.
- Currently, materials for projects are delivered to the site and stored somewhere, requiring part of the building to be constructed before materials can be handled effectively. Procurement of materials is a logistical hassle and trucks go in and out of job sites all day bringing shipments. Further, great amounts of trash are created, being hauled away in dumpsters.
- Profit:
- While construction’s dangers are a primarily human impact, the costs of injuries are incentives for companies to be safer. Workers getting hurt or killed prompts fines, lowers public opinion, and makes it harder for companies to find laborers.
- Given the numerous safety benefits of modular construction, workers should both be and feel safer on the job. Safety controls would be easier to engineer and enforce. Safer work is faster work, and it tends to be better quality as well.
- Normal construction proceeds as follows. The site is developed and foundations are built. The structure is erected, and MEP pipes and wiring follow it. Exterior walls, then interior walls, and finishes follow. Quality control is conducted simultaneously to MEP pipes and wiring until finished. Finally, the site is restored and the building is certified for occupancy.
- Going modular allows site development and foundations to be constructed while the modules are being built. Quality control is built right into the module construction process, so all that remains is installing the modules. It tends to take a little more time prior to construction to engineer the modules so they can be constructed and brought to the site, but once that’s done, modular construction proceeds much faster than normal methods used today.
- As previously discussed, traditional construction practices are energy inefficient and create large amounts of waste.
- On average, about 40% of embodied building energy use occurs during construction, with the other 60% occurring over its life cycle. While the construction energy use isn’t the main culprit, any savings here can help structures get closer to net-zero.
- Similarly, the waste produced by construction is expensive to dispose of, and it’s generated in such large quantities that it can be problematic. Reaching agreements with manufacturers to reuse packaging could reduce overall construction costs significantly.
- Over the past few centuries, construction productivity has stagnated, which stands in stark contrast to other industries (such as manufacturing) where progress has increased with time. This is despite numerous technologies coming into play, such as BIM, CAD, increasingly complex analytical software, and new scheduling systems.
- While it’s seen use, modular construction remains relatively untested on a large scale, though it’s becoming more common. Many recent innovations in construction have focused on building design and tracking productivity and quality, with little focus on making buildings go up faster. Modular construction stands to help not only productivity and quality tracking, but also construction time!
- While construction’s dangers are a primarily human impact, the costs of injuries are incentives for companies to be safer. Workers getting hurt or killed prompts fines, lowers public opinion, and makes it harder for companies to find laborers.
Conclusion
Modular construction is a highly situational but potentially incredibly effective construction tool that the industry is, at present, simply scratching the surface of. As advancements continue to be made in building energy efficiency, construction energy use will take up an increasingly larger portion of a building’s energy use over its lifetime. Similarly, advancements in construction technology will cut down on waste. Modular construction stands in a unique position to reduce both construction waste and energy consumption, and will become essential to sustainable construction in the future.
Very nice and informative blog. This blog beautifully explains the positive impact of modular construction on the triple bottom line – people, planet, and profit. It’s enlightening to see how this approach not only boosts efficiency and profitability but also aligns with sustainability and social responsibility.