Modular or prefabricated building methods are pitched as a way to cut down on labor, material, time and costs. And because most of the construction work is done in a factory setting instead of in the field, it’s also presented as a safer option.

But work on modular projects, both in the factory and on site, isn’t without hazards. That said, the number of hazards are lower and standards different, experts say. 

Work in a controlled factory setting means that employees face less risk for changing site conditions, said Amit Haller, co-founder and chief executive at Hayward, California-based Veev, which builds modular homes. 

Veev builds most of its homes — which are about 2,500 square feet — in a factory, where workers aren’t subject to heat, wind, rain or storms. 

“Whatever we can do in the factory, we move to the factory because it’s a much more controlled environment and much easier to deploy safety regulations,” Haller said.

A factory setting means it’s also easier to cut down on debris and keep the environment clean. Builders can deploy technology like robotics, “which are reducing significantly the number of people interacting with a dangerous task,” he added.

Building modules in a factory setting also reduces fall risk simply because employees work from lower heights. Falls killed 390 construction workers in 2021, according to the most recent OSHA date, more than any other cause.

“In the factory everything we do is at grade,” said Vaughan Buckley, CEO of Philadelphia-based Volumetric Building Companies, which has five factories across the world and builds for a variety of sectors, including housing and hospitality.

In addition, fall protection is easier to install and maintain in an environment that doesn’t change much vs. the field, where conditions can change constantly.

Buckley said that they have also found more ease with supervision and quality control in a factory setting. The company uses a combination of a safety team and artificial intelligence to “identify when PPE is lacking on the floor, and when folks are doing things that are unsafe,” he said.

Of course, no work environment is 100% hazard free. In modular assembly facilities, the majority of common worker injuries mirror those of traditional factory work, such as soft tissue injuries, like strains and sprains, he said.

Safety by setting

Once prefabricated units arrive at the jobsite, a new set of safety standards comes into play. Curtis Chambers, certified safety professional and president of OSHA Training Services, said that OSHA regulations differ from the factory to the field. 

For example, home-building activities that take place on a construction site would follow OSHA construction standards. But components fabricated in a shop-type environment are regulated by the OSHA general industry standards. 

If a builder fabricates in a factory and then assembles components in the field, then both apply to their relative environments, he said.

“You have to make sure you understand which set of rules apply,” he said. For example, the threshold for needing a fall protection system in the shop is 4 feet, whereas the threshold for construction is generally 6 feet or higher, depending on the jobsite.

Chambers added that workers should be trained and skilled up for the environment in which they work. Someone who builds components in a factory may need additional training to then put together those components in the field. 

“You don’t want someone used to climbing up and setting a 2x6 and 2x8 rafters, and all the sudden they’re swinging panels,” he said.