Embracing Mass Timber Building
By Steve Conboy
We are in the midst of a serious housing crisis in the United States.
As home prices have increased – in many areas surpassing the peaks of the market before the Great Recession – home ownership has declined. At the same time, the percentage of income families spend on rent now exceeds previous levels. The rising homeless populations in many cities are a testament to the lack of safe, affordable options.
There is no question – America needs more affordable housing, and we need it fast. Modular construction, particularly using new-growth cross-laminated timber (CLT) and nail-laminated timber (NLT), can address the demand promptly.
In the 19th and early 20th centuries, populations shifted to the cities, as industrial and commercial job opportunities expanded in metropolitan areas. In the years after World War II, urban and suburban areas boomed, as G.I.s returned home to find work and start families. The suburbs, many of them enabled by the newly created Interstate Highway System in the 1950s, quickly became the model for family neighborhoods.
To address the post-war population boom, houses in the suburbs were often constructed with modular components, using the same process as apartment buildings in the cities. By prefabricating single or multi-story buildings in sections and delivering these sections to the development site, modular construction allows for a much faster completion time than site building alone.
Constructed on an assembly line, modular construction can take as little as ten days and can be delivered with mechanical, electric, and plumbing installations as well as interior furnishings. The resulting structures are also compliant with all applicable local building codes.
Take Levittown, New York, for example, America’s first true suburb, where a 27-step construction process modeled on the assembly line could create an entire house in a single day, complete with a picket fence and appliances in the kitchen. The houses were simple but, for families that had lived through the struggles of the Great Depression, largely in cramped urban areas, these homes were a dream come true. During the early years of the suburbs, modular homes were primarily built using old-growth timber. Once that supply of old-growth wood was exhausted, new-growth wood has been required as a substitute for smaller projects while concrete and steel were primarily used for larger construction projects.
Both substitutes, as currently used, have serious limitations. With concrete and steel, costs are dramatically higher, for the materials themselves, time and labor, as well as for transporting the components. Tariffs on imported steel also make these models more expensive.
When building with more environmentally friendly new-growth wood (wood that can be grown an harvested in a five-year span), the threat of three major items – fire, mold, and termites – has led to restrictions on the size of timber buildings in local building codes.
But lumber technology has improved dramatically in recent years. CLT and NLT, in which panels of new growth wood are glued or nailed together, offers the strength and durability of old growth wood or even steel, along with increased resistance to fire, mold, and termites.
Combined with treatments that improve fire resistance even more by reducing the flammability of wood and the smoke generated by fire, these technologies will supercharge modular construction with wood quickly providing more of the affordable housing that our nation desperately needs.
Just in the past few years, developers in Newark, New Jersey, Portland, Oregon, Vancouver, and other cities are already constructing or attempting to build mass timber structures with CLT and NLT. Timber offers the modular industry and builders a renewable resource at a fraction of the prices of concrete and steel and often results in lower construction costs by allowing builders to complete projects more quickly. An 18-story mass timber student residence at the University of British Columbia in Canada was recently completed a remarkable four months ahead of schedule
With modular construction, such projects have the potential to transform the already-critical role of modular homebuilders and the market for affordable housing. Beyond the speed of construction, there are other reasons more and more builders are turning to modular construction. By assembling components indoors, high-density modular construction planning avoids the delays presented by bad weather and the disruption of completing a lengthy project on a busy street.
Combining these benefits of modular construction with mass timber can reduce the amount of time required for an architect’s blueprints to evolve into a completed structure for families to call home.
This change will not occur by itself. Beyond the construction industry, we need more modern policies that support mass timber building by replacing yesterday’s building codes and allowing for higher-density construction in urban and suburban areas.
Where the enormous need for affordable housing exists, pioneers in the design and construction industries will lead this fight to create new opportunities in housing through the modular construction of mass timber buildings.
Plan for the future with projects capable of going taller and wider and providing greater density and efficiency.
Steve Conboy is the chairman and general manager of M-Fire Suppression, Inc. He has been involved in the lumber & building industry for more than 40 years, starting at a union carpenter in New York. Today, he provides clean fire inhibitor protection to defend all types of wood-framed projects for the building industry.