Modular Design Methods: 3 Ways Developers Are Adapting
Major players discuss the innovations that are rapidly transforming the growing subsector.

As the multifamily space becomes more open to the idea of modular design, non-traditional building methods have become more popular. Despite the pervading conventional wisdom, modular builders are quickly innovating and adapting their products to particular metros and market demands.
As the subsector becomes more popular, it is quickly becoming apparent that no two firms are approaching modular design in the same way.
A vertically integrated approach
A key benefit of modular design is its ability for standardization: once a kit of parts is created, execution becomes efficient and timely. Greystar has vertically integrated these kinds of products, manufacturing modular housing components for the firm’s internal use rather than for sale to a third party. This approach has allowed the company to further optimize its factory production, Andy Mest, managing director of U.S. development and construction told Multi-Housing News.
“The level of standardization we’ve come to is game changing, to say the least,” said Mest. “And it really helps, not only from the factory side, but also on the trade side, because they get that same consistency and repeatability.”
Greystar’s multifamily modular products are designed to include a limited amount of customizable units. While the number of different layouts that could be designed are seemingly endless, devising a standard set of modules has made the process of bringing modular housing online relatively seamless.
The firm is focused on variations of homes ranging from studios to three-bedroom units with a den. Size-wise, apartments range from approximately 500 square feet up to more than 1,400 square feet. Small variations can be made to the product, such as allowing for spaces for electrical rooms, janitors’ closets or elevators. The goal, Mest explained, is to create a diversity of product type that can cater to multiple price points within a singular project.

Multifamily modular developments by Greystar are designed using light gauge steel rather than a traditional wood frame. This eliminates concerns over the frame developing mold or mildew and there is no structural differential settlement or shrinkage to worry about down the line.
Greystar’s standardized process is also beneficial for onsite trades teams, according to Mest, who identified getting subcontractors onboard as one of the biggest challenges in modular development. Finding a subcontractor willing to work within the unique parameters of modular construction can pose a challenge but with well-laid out drawings and designs, and a standardized process, it is an obstacle that can be overcome.
“The beauty of our process being vertically integrated is that we are able to continue to amend our design even through the build of the first project,” Mest said. “We’re able to make changes on the fly as we’re in production, implementing things that are betterments for the onsite trades to accelerate our delivery and make the ease of onsite connectability better.”
Greystar’s particular process can make its projects’ development and construction process 40 percent to 50 percent faster. When this happens, overall financing costs and the lease-up process become easier to navigate and the project becomes more lucrative.
The real benefit to vertical integration, Mest believes, is the firm control the company has over everything that goes into its modular design, including the sites selected, the products that go into the building and the unit mix. “I do think there’s significant advances are coming along with artificial intelligence and design learning,” Mest said.
A customer-oriented design
For Westchester Modular, many of the traditional design and building methods deployed in multifamily cross over into modular. Building materials are largely the same too. “We custom-make stick builds inside of our factory,” John Colucci, vice president of sales and market at Westchester, told MHN. “We just do it in queues. It’s like Legos. So it really doesn’t matter how small or big the building is.”
One major upside of Westchester’s modular design process is that it saves time. While the foundation is being built, the units themselves are being constructed. And once an apartment reaches the site, each home is already 70 percent to 80 percent complete. Units come with painted walls and pre-installed bath fixtures, shower stalls, plumbing and cabinetry.
Some developers come to the factory with a conceptual design ready. However, if they haven’t, Westchester first works off of the overall project footprint, then moves into discussing a price range. Next, the company can begin designing a 3D design with Chief Architect software, customizing elements of the building to meet both the building envelope and the market.
READ ALSO: Is Modular the Best Solution to Multifamily’s Big Supply Problem?
“The engineering department draws all the plans necessary for the builder to get a building permit,” Colucci explained, another plus side to modular design versus traditional. “As a modular home manufacturer, we’re required to have a third-party inspection agency.”
But the units can’t be sent everywhere. Westchester designs within a 300 mile radius of its factory. Department of Transportation regulations make transportation tricky and expensive. Another limitation is that anything with a ceiling height greater than 9 feet can’t be transported. Beyond those limitations, Colucci cannot imagine anything would stop Westchester Modular from building a multifamily modular project.
“There’s still a very big conception about what modular really is,” Colucci said, suggesting that people with questions go tour a facility.
As the industry becomes more technologically advanced, modular developers are able to increase efficiencies as well as the amount of customization that comes with a design. The beauty of modular is that builders can now have more design choice both on the interiors and exteriors of a project, said Colucci. Once the majority of the units and its components are installed, the developer can add in whatever sheathing, siding or façade they wish to make the building their own.
“We’ve really been able to adapt different technologies into what we do and build something that’s a customer-oriented design,” Colucci said.
Modular in a composite based building system
When compared to traditional builders, modular has the advantage of being a single-stop shop. At least, that’s the reality for Northstar Technologies Group. Kyle McLaughlin, chief sales officer at the company, said his firm is a manufacturer at heart. Its “bread and butter” is designing panelized or modular projects in a composite-based building system.
NorthStar’s properties are constructed using a fiber-reinforced polymer that can withstand up to 250 mile per hour impacts, is ballistic-rated, Class A fire-rated and four times more energy efficient than traditional materials. For multifamily investors and developers, modular made out of FRP allows for maintenance costs to go down. Structural degradation isn’t an issue, said McLaughlin, while insurance is approximately 30 percent lower than at similar properties. Removing high-cost insurance barriers to entry makes modular financing easier to acquire, too, while the lightness of the material makes it easier to ship on a flatbed tuck.
When it comes to the design process, the first step is the conceptual stage. “We’re figuring out the max density for the proposal and then we’re engaging our design team and our civil team to conceptually draw everything out so that we can propose it to the municipalities,” McLaughlin said.
The schematic phase follows. Often times using AutoCAD for design work and SOLIDWORKS for the modeling for the engineer, NorthStar Technologies moves on to detailed work dimensions, spans, hallway sizes, ADA compliance steps, etc. The last two stages of the design process, civil and engineering, happen at the same time. The structural components are sorted, such as the engineering details and FRP connections, and civil layouts, like roadways and traffic studies, are done. By the time the modular units hit the site, they are already some 75 percent complete.
The only drawbacks to the design process, McLaughlin said, is that the project is subject to the limitations of a square box, but creative design can allow for multiple layouts. “We can do just about anything,” he noted, and the final product is precise, down to 1/18th of an inch.
With the major influence technology is having on the construction industry, as well as the power of social media, McLaughlin anticipates seeing a much larger adoption of prefabricated and modular components in the next five years. At the end of the day, it comes down to education and getting the word out about the option.
“We’re really peeling back the layer on our engineering and our manufacturing process and educating people in the materials that we use to show them that this way to build is better,” McLaughlin said.