With supply chain shortages, modular may be a sustainable solution
By Don Neff
It’s no surprise that supply chain disruptions have driven lumber pricing upwards to more than $1,600 per 1,000 board feet in the Spring of 2021, only to drop to $500 by the end of the third quarter. Presently, the pricing has risen again to $1,000-1,200 and is expected to continue rising to about $1,300-1,400 by January 2023.
British Columbia wood producers were hit by fires, floods, wood-boring beetles and almost double export duties into the U.S. by late 2021. In past years of peak pricing trends, builders shifted to alternative construction methods such as light gauge steel, with 25% recycled content and more panelized components.
Switching from wood to steel in the past created other issues such as production schedule delays as crews had to develop and learn new production efficiencies. Engineered products such as truss joists (TJIs), structurally insulated panels (SIPs), web trusses, pre-packaged floor and roof “cassettes” were yet another evolution for both wood and steel materials. TJIs provide longer span distances allowing greater design flexibility.
Continuing construction labor shortages have also driven product manufacturers toward these pre-assembled and more structurally robust engineered solutions. Roof trusses as a prefabricated solution have gained a substantial footing over the years in the construction industry, accounting for 60-75% market share over traditional roofing methods.
Full modular has only a 3% market share while panelized walls have a market share of less than 2%. With such a presently low adoption rate, there will be more opportunities in the future for innovative builders.
Modular construction systems provide a climate-controlled production environment, assembly line precision in quality and more predictable delivery schedules. Coupled with growing design flexibility, modular “off-site” housing construction methods have merit, but aren’t without risk.
At the International Building Show this month, substantial time was devoted to this discussion through panel presentations for eager audience members seeking to learn more about “off-site construction” solutions. Given the heightened interest, more communities are being served by modular construction solutions.
“With such a presently low adoption rate, there will be more opportunities in the future for innovative builders.”
From 1908 to 1942, Sears Roebuck offered “modern homes” with pre-cut and labeled framing packages, and everything was included—even the kitchen sink. Such “modular homes” were delivered in a railroad box car containing 30,000 parts ready to assemble by enterprising entrepreneurs.
Lean production practices and experience-driven efficiencies can reduce field waste, leading to reduced consumption of energy, water and materials, improved health indoor air quality and reduced environmental impact. The advantage of factory built modular construction includes a huge reduction of material waste on jobsites, where builders sadly pay twice; once to purchase their bulk lumber supplies, and again to haul waste material to the landfill. This is neither efficient or effective.
Contributing market drivers toward off-site construction systems include increasing interest rates—raising the cost of production and qualified labor shortages—which will not go away in our lifetime. The reality is most new workforce entrants are ever more technology focused which is the antithesis of construction.
In fact, innovation in construction has been stagnant for decades, except for computer aided design methods and modular construction practices. Fortunately, building industry leaders have recognized the need for enhanced construction trade training and have successfully sponsored programs across the U.S.
Modular construction risks revolve around three phases:
Phase 1: Adapting the proposed architectural and engineering design into a factory (modular) production solution.
Phase 2: Dealing with complex and integrated delivery logistics in getting the modular components to the site, with the factory controlling the shipments and carriers.
Phase 3: Field assembly at the site, requiring precision in the foundation work by others.
Designing the structures in a CAD/Revit environment on the front end can respect standard dimensions which other related product suppliers rely on, such as for production flooring which comes in standard widths, eliminating unnecessary waste in the field.
Designing and transporting the modules also requires adaptation in dimensional logistics for overpass heights, as well as length/width of common carriers. If the transport carrier is not owned or controlled by the factory, disputes can arise at the point of hand-off from one stage to the next if damages occur in transit.
The factory-built solutions will require site work contractors to be precise with placement of their foundation anchorage systems, whether providing a crawl space or full basement. Conventional wisdom is that modular homes designed for slab on grade construction methods tend to be less structurally robust.
Modular construction practices may take the sting out of rising lumber prices particularly when coupled with the frustrating lack of skilled labor.
Don Neff is President of LJP Construction Services. He may be reached at www.ljpltd.com.