In the midst of an ongoing housing crisis, more attention is focusing on modular construction for its efficiencies in labor, time and costs. Those efficiencies stem from the modular construction process, but can be exponentially improved with simple design.
Otis Odell, housing and mixed-use sector leader at design and construction firm HED, began exploring modular construction years ago in ski resort towns where the building season was limited by the climate. While he now advocates for the method, he acknowledges it has challenges.
In one of his recent projects, despite having a well recognized general contractor and fabricator, the project team still wasn’t able to realize its targeted results because of ongoing, known challenges.
“Achieving cost and time savings with modular in some ways depends on some level of standardization that has little to no variation or complexity,” he advises. “You start to understand what is important about the design is that it can deliver a functioning kitchen, a place to eat, has light, has outdoor space access, and if those unit layouts are repeated hundreds of times that’s OK because what ultimately makes it home is what the resident brings into the space.”
To realize the efficiencies and standardization, a project has to start and finish with strong cross-functional collaboration. The project’s architects and fabricators have to coordinate closely to ensure modular-friendly designs. Any time there are misaligned expectations between stakeholders, it can take the budget and timeline completely off the rails.
“The fabricator making shop drawings should get all stakeholders together to understand the scope of work of each entity, the general contractor and major sub trades, in the pre-construction phase,” Odell said. “When they aren’t familiar enough with the scope to provide actual pricing, it leads to a miss on project goals.”
A New Modular Approach
Odell has a vision to create a platform that flips the script.
“Instead of a standard process to deliver housing – design, award, price – I want to flip it to be price, award, design,” he said. “Typically, a firm is asked for a preliminary package and they rarely can match budget so we are creating a pricing module with three years of information in a database with number of units, unit mix, zip code, and it can generate a price in seconds.”
With well-defined scopes, Odell believes he can deliver units at an 85% ready level with a ready set of drawings including all BIM models so it is easy to collaborate with a fabricator.
The standardization and efficiency that Odell wants to deliver for housing is a reality for hospitality projects he has been involved in.
“The quantity of modules through standardization is essential, and we were able to get the number of modular types from 11 to 7 for a standard hotel layout,” he said. “It took $2 million out of the project costs from the fabrication standpoint. Reducing the variations is easier in the hospitality space than in the housing space.”
Right now his company has created six bay designs that can deliver a studio, plus one-, two- and three-bedroom units with the goal to have 80% permit ready documents of the modules. Odell anticipates that in housing, there will be a need for customization and variation, so he’s working on computational design and using scripts that will have the ability to respond to clients’ and developers’ goals.
Some groups, like Model/Z, also are experimenting and exploring standardization efficiencies to deliver attainable workforce housing projects across the country.
Modular Achieves Flexibility and Sustainability
Whidbey Puzzle Prefab is approaching modular construction in a similar way—focusing on the replication.
“We saw an opportunity to create a higher quality, more sustainable product that could be replicated,” said the company’s architect Matt Wittman. “Flexibility is the key factor. A lot of prefab has larger modules, we divided it into multiple smaller units to be easier to be transported on any highway without special permits. That was a driver.”
The modules are flexible and interchangeable to be put together in multiple configurations; assembled in infinite ways that can be custom to the set location, whether it is in the city or the woods, in Florida or in Maine. Modules are premade individually and then connected with outdoor walkways that all sit on a pin foundation with a ring beam producing walkways and decks as in between space.
Net-Zero Energy and Low-Impact Modular Design
The modules also are light on the land and environmentally sustainable. Modules have solar, heat pumps, hydronic heating and cooling, energy recovery ventilation, and smart home controls to monitor energy use. These features support the advanced insulated envelope to meet net zero. The roof is extra insulated, achieving R-50, which is a 70% increase over base line code, and the walls are double the code.
The roof also is designed to channel rainwater into a tank where it can be purified with a custom filtration system to be safe for use in kitchens, bathrooms, showers, washing machines, and dishwashers.
Whidbey shared a cost breakdown, which is based on the company’s current low volume, but at scale could break through some affordability challenges. The prototype project costs $676 per square foot. With the net zero, off grid design, operational costs are eliminated.
No concrete is used since the home uses a steel ground frame foundation with hand set micro pin piles that also mean less ground disturbance. This unique foundation can reduce the carbon footprint by 77% compared to a concrete foundation.
The pin foundation has to be engineered to meet the same criteria as a conventional concrete foundation, so it is equal in performance. A conventional concrete foundation would have 30,000 pounds of Co2, the pin foundation is only 7,000 pounds, and meets all the same structural requirements. The install labor is about the same, but the pin foundation doesn’t need any excavation, so time and labor is saved there, along with the fact that there is no destruction and impact to the earth.
Currently, the modules are manually assembled in a factory with builder partners.
The Future of Modular Housing
From Odell’s data-informed, repeatable designs to Whidbey’s flexible, net-zero prefab systems, the future of modular housing looks increasingly sustainable, scalable and cost effective. While customization remains a hurdle, innovations in computational design and manufacturing partnerships are pushing the limits of what prefab construction can offer.
As modular solutions evolve, they promise to transform how we build homes in the years ahead.
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