Material selection is an important component of the architectural process. As you reach Design Development, your architect will present options for structural supports, exterior claddings, and interior finishes.
Every material has financial and environmental implications. But whether you wish to reduce your environmental impact or maintain your budget, you are likely to find something to love in mass timber. Known for its strength and durability, mass timber offers a cost-effective and sustainable alternative to conventional structural materials like steel and concrete.
In our experience, mass timber offers four benefits:
- Sustainability
- Fewer workers
- Reduced materials palette
- Biophilic design
In this article, we will break down each benefit so you can better understand how this material can impact your project.
What is Mass Timber?
Mass timber consists of wood planks that are either glued, nailed, or dowelled together to create a strong and durable material for structural beams, walls, floors, and more. Europe has been using the material since the 1990s, but it has only recently gained popularity in the US. Due to its strength and stability, it has become an alternative to steel and concrete.
There are four common types of mass timber:
- Glue laminated (Glulam)
- Cross-laminated timber (CLT)
- Dowel laminated timber (DLT)
- Nail laminated timber (NLT)
Each type has a variety of applications. Glulam is often used for beams and columns, while CLT, DLT, and NLT are often used for structural elements like walls, floors, and roofs. Both DLT and NLT have a horizontal direction. CLT, on the other hand, has a two-way span.
Depending on your project, you may use a combination of timber types. 111 East Grand, for example, features Glulam columns and beams and a DLT floor deck.
111 East Grand used Glulam columns and a DLT floor deck.
Benefits of Mass Timber
Mass timber is becoming a popular choice for many building owners—and it’s easy to understand why. When compared to other load-bearing materials like steel or concrete, mass timber offers many benefits.
1. It’s Sustainable
First, mass timber is more sustainable than steel or concrete. When harvested from sustainably managed forests, timber construction can reduce carbon emissions.
According to the American Institute of Architects (AIA), the built environment is responsible for nearly 40% of global carbon emissions. Producing and transporting building materials–especially steel, concrete, and iron–contribute to 11% of these emissions.
Mass timber offers a low-carbon alternative. Mass timber’s ability to sequester carbon can potentially offset the carbon emitted during its manufacturing. Studies show that replacing steel with timber could potentially reduce global carbon emissions by 15-20%.
DLT is perhaps the most sustainable of the four types of mass timber. Made entirely of wood, it is more recyclable than NLT. At the same time, it does not use any glue or adhesives, which reduces the risk of off-gassing during occupancy. These benefits make it one of the most sustainable options on the market.
2. It May Require Fewer Workers During Construction
Depending on the project, constructing a mass timber building may require fewer workers on site. Mass timber products are cut to design specifications before arriving on-site.
A CLT wall, for example, can be cut with window opening and spaces for plumbing and electrical conduits on the factory floor. The prefabricated pieces can then be shipped to the construction site for assembly.
Easy assembly and precise connections can potentially reduce the number of workers needed on site and the amount of time it takes to complete the project. Keep in mind: the same can be said for pre-cast concrete panels, which are also poured and cut before arriving at the construction site. The sustainable aspect of mass timber, however, may make it the superior option for some.
Mass timber products are cut to design specifications before arriving on-site.
3. It Can Help You Reduce Your Materials Pallette
Mass timber can also help you reduce the number of materials used in your building, resulting in a more sustainable and efficient construction process. Mass timber is lighter than both concrete and steel, which allows for smaller foundations and less concrete.
At the same time, using mass timber can minimize your interior materials palette. On a conventional building, plumbing and wires are often covered by gypsum or drop ceilings. Mass timber, particularly DLT, allows you to integrate plumbing and electrical conduits directly into the wooden structure.
In turn, the wood deck can be left exposed and serve as the ceiling. This efficiency reduces the number of materials used and can lead to savings, depending on the project.
Plumbing and electric conduits can be integrated into the structure.
4. It Can Connect Occupants to Nature
As mentioned, wood is often left exposed on many mass timber buildings, creating an attractive interior finish at no added project cost.
Exposed wood is more than an aesthetic choice, however. It also offers psychological benefits and can promote occupant wellness.
Biophilic design is the use of natural materials, daylight, and natural elements like plants in the built environment. Research finds biophilic design elements can reduce stress, increase energy levels, and improve productivity.
Visual connections to nature can have a tangible impact on your organization. Along with daylighting and views, natural materials like exposed mass timber can help occupants feel more energized, at ease, and connected with the outdoors. In short, mass timber can help make your building a healthier and more productive environment.
But wait, is it Fire Resistant?
Let’s take a moment to address the elephant in the room. Despite the environmental and financial benefits, misconceptions about wood construction can make some hesitant to adopt mass timber.
Contrary to popular belief, a mass timber design will keep the structure safe in the event of a fire. During fires, mass timber chars on the outside and insulates the interior wood from damage, maintaining the building’s structural integrity. This insulating feature makes it just safe (if not safer) than other structural systems.
Ready to Learn More?
Material selection is an important step in the design process. When you are selecting materials, consider your long-term goals as well as your initial budget. Although mass timber may have a higher initial cost than steel or concrete, it is far more sustainable and can lead to a more efficient construction process.
Mass timber’s biophilic design properties can also promote occupant wellness. Learn more about occupant health and wellness by reading our guide to long-term personnel costs.