I loved playing with Lego blocks as a kid. I liked the idea of using similarly-shaped objects to be able to build a variety of different structures. In modern building construction, shipping container-sized modules, pieced together like Lego blocks, are a growing trend. Long Island City, N.Y.-based UA Builders projects there will be a 6-percent increase in modular/off-site building construction by 2022. Projects ranging from tiny to colossal are going modular. What does this imply for the rest of the building community?
A typical shipping container is 320 square feet of space. Single shipping containers are becoming popular for tiny homes because they can be transported on a truck and the structures are built to be weatherproof. Tiny homes are also a great way to repurpose retired shipping containers. A Dwell article shows 11 different floor plans composed of one or several shipping containers.
For a small, but not tiny home option, Ryan Wallace has a plan. Solar Home Factory is a modular home manufacturer, started by Wallace. In 1995, he added a solar photovoltaic system to a family cabin. A few years later, he built a zero-net energy (ZNE) home on-site in Geneva, N.Y., and now has taken up modular construction.
Today, Solar Home Factory has three bays where it creates ZNE homes. It makes three different modular-unit homes in sizes up to a total of 1,050 square feet. With millennials and second-home owners in mind, these modules are designed to connect on-site and stay off the grid. Solar PV panels, an air/water heat pump and an energy recovery ventilator are preinstalled for the HVAC.
Wallace’s concept scaled into a 20-home subdivision project called Lake Tunnel Solar Village. This development in downtown Geneva sold the first phase of units in two weeks.
For a medium-sized project, 461 Dean in Brooklyn, N.Y., is now the site of a 32-story apartment complex constructed of modules. Wired reported that 90 percent of the construction was completed off-site. This is a mixed review for modular building. Initially, the developer claimed, “The structure would be ready 18 months sooner and cost 20 percent less than a conventional tower.”
Unfortunately, this project took two years longer than expected and went millions over budget. One lesson learned here may be that triangular-shaped buildings, such as 461 Dean, are trickier to construct, especially with modules.
Large-scale modular buildings
On a very large scale, the Ras Abu Aboud stadium in Doha, Qatar, will be built with modified shipping containers. Dezeen reports that this 40,000-seat soccer stadium will be one of the host sites for the 2022 Men’s World Cup. The inside of the shipping containers will be prefabricated off-site. As an example, two modules will arrive at the location to serve as bathrooms. All the plumbing, fixtures and finishes will already be completed. Similar to an RV, a couple of simple connections will make the rooms ready for use.
Interestingly, since this stadium is modular, this entire building could be moved to another site after the World Cup, if you know anyone who is in the stadium market. The current location is right on the water in Doha, so the stadium could be loaded on a cargo ship and taken somewhere else in the world.
The race to the tallest building in the world is now modular. Back in 2013, Sky City in Changsha, China, was planned to be the tallest building in the world. The cool twist is that it was intended to go from zero to more than 2,700 feet tall in 90 days! The plan was to spend about 120 days building modules off-site and then assemble the whole structure in three months. The current tallest building, Burj Kalifa in Dubai, UAE (2,722 feet tall) took about five years to build.
The Sky City project ran into some regulation issues and stalled. The site is currently a fish pond, so they have a long way to go there. Technically, Sky City is actually below grade right now, which is not going to set any skyscraper records.
Another modular project that is creeping along is the Jeddah Tower in Saudi Arabia. This skyscraper is aiming to be over a kilometer tall (3,281 feet), which would make it the tallest building in the world. It is unclear if this project will be completed by 2020, as construction was suspended at one point. There was early concern about hoisting prefabricated building modules so high by crane, based on wind loads.
This tower has a different twist on the modular concept. There are yellow construction modules that look like they are creeping up the building story-by-story. Basically, the modules are workshops the builders use to complete the facade and then they move up to the next level.
Prefab for productivity
What does modular construction mean for the traditional builder in the United States? There is huge opportunity to do more work off-site. I think if most contractors counted up the hours they spend driving to sites and finding parking, they would be unhappy with that number. In traditional construction, the industry spends a lot of time not building.
Some things can’t logistically be constructed off-site and delivered. However, with careful planning, a fully equipped mechanical room could be built on a steel structure and delivered to a building’s mechanical room.
One of the heating contractors I know in Colorado, Cheney Plumbing and Heating, has been building hydronics modules for years. It prefabricates most of the boiler panels it installs at its shop in Carbondale. A big plywood wall is where techs hang the boiler and pipe, together with all the components they can fit on a panel. Each of the pieces will slide into a truck and have minimal system connections in the field.
Cheney Plumbing’s service market is the valley that extends up to Aspen, Colo. Building a boiler panel in the comfort of a heated shop right next to all the proper tools and parts is efficient. There are plenty of snow-filled days in this part of the country, so prefabrication is a smart tactic.
A potential benefit of modular construction is an accelerated construction timeline on-site. Instead of impacting a neighborhood with construction traffic and noise for extended periods, large structures could be a series of container deliveries with streamlined field connections.
While modular prefabrication won’t work for everything, it may be a way to maximize the working hours in a year, in the comfort and control of a shop. Could you incorporate some modular construction in your next project? l
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