Mass timber construction is when large amounts of wood are used instead of concrete, steel, or other materials that take a lot more work to build with. Mass timber is used by more and more people in the construction industry because it strengthens buildings, saves time, and reduces costs. Mass timber construction has many advantages compared to cheaper and more traditional materials like steel or concrete.

Mass timber buildings have a much smaller carbon footprint than other kinds of structures because they give off fewer emissions. They also use less energy than buildings made of concrete or steel because they are lighter and can be put together with smaller tools, reducing the energy needed to make the building.

What is mass timber construction?

Mass timber construction is a new way of building that is being tried in many places worldwide. The main idea is to use wood instead of steel and concrete as the "primary material."

Scientists argue about the environmental pros and cons of mass timber construction. Still, everyone agrees that it has advantages over traditional materials like concrete and steel regarding fire safety, acoustic comfort, natural airflow, thermal efficiency, increased resource recovery during recycling or demolition, and less embodied energy.

How to design a mass timber building?

Like the timber frame buildings of centuries past, mass timber construction relies on big timbers to do the heavy lifting and provide exceptional stability. These "mega-sized" panels are what make this system so appealing from an environmental point of view. They also make it possible to build solid structures that last a long time without sacrificing the integrity of the design.

How well mass timber works as a building material depends on how much wood it has, how thick it is, and how big it is. For example, each story of a midrise building can be made from cubic meters of wood. The architect has to determine how many levels the project needs and choose the right size.

What are the types of mass timber products?

Cross-laminated timber (CLT), glue-laminated timber, and solid wood are the three main types of wood. All three are available as boards with panels, single sheets, and panels already assembled.

CLT is the most used product because it is the most stable and, therefore, the most flexible of the three. CLT is more durable than other products because it comprises layers of solid wood.

• Cross-laminated timber (CLT)

CLT is made of solid-grained, perpendicular pieces of wood, usually, spruce or pine, glued together in horizontal layers. The panels are strong because each board is a structural part.

• Glued and laminated wood (glulam)

Glulam is made of solid-grained wood cut into square or rectangular beams and then glued together to create a panel (see below). The glue could be exterior-grade resin, glue linings on the inside, or a mix of both. In the United States, bonds used to join glulams must meet standard D-4006 from the American Society for Testing and Materials International.

• Solid wood

Solid wood is made of straight-grained lumber milled into square or rectangular beams and then sawn or forged into a panel (see below). The pieces may be held together with nails, steel connectors, or other hardware, but the panels are not glued together. Solid wood comes in more sizes and shapes than glued-laminated and cross-laminated timber.

What are the value-added benefits?

• Sustainability

CLT panels are made from 100% recycled materials, which makes them suitable for the environment. They use less energy to produce than framing and OSB and don't need to be painted after construction. 

• Safety

Traditional buildings with wood and frames can be dangerous. These risks can be lessened by engineered systems, advanced fire safety strategies, and new ways to protect yourself.

• Efficiency

The Forest Stewardship Council says that compared to traditional wood framing, CLT uses 80–90% less energy to make. It needs less glue, paint, and other usually expensive maintenance products. 

• Durability

Mass timber buildings are more robust than framed buildings but use less material. Mass timber buildings also need less maintenance, which saves money and helps the environment. Also, the panels can be taken off the structure and reused. This process can reduce the amount of wood used and make it easier to reuse wood products.

How Can a Developer/Owner Get Started with Mass Timber?

• Help with the Design

The National Design Specification (NDS), made by the American Wood Council, and other design standards can help with mass timber design. The NDS also includes construction drawings and product specifications for a safe and long-lasting project.

The National Design Specification (NDS), made by the American Wood Council, and other design standards can help with mass timber design. The NDS also includes construction drawings and product specifications for a safe and long-lasting project. Environmental Assessment

• Help with building (pre-construction)

The National Design Specification has a Mass Timber Planning Package that can help build with mass timber (NDS). This guide shows a developer how to plan a project and do an environmental assessment. It also has information about where to find more information.

The National Design Specification has a Mass Timber Planning Package that can help build with mass timber (NDS). This guide shows a developer how to plan a project and do an environmental assessment.

• Construction support (post-construction)

There is help for mass timber construction in the form of a design outline, which shows what goes into a mass timber building. The system tells project teams how to design and build mass timber buildings that meet safety standards and take less time.

• Outreach for Sustainability

The Sustainable Building Program aims to get commercial, industrial, and institutional building projects in Oregon to use sustainable building practices, technologies, and designs. The program also helps fund research to make buildings that use less energy and cost less money to run. It also serves as a resource for low-impact, low-cost building materials, and technologies as they become available. Many of the companies that make mass timber will be able to help meet these goals.

For starters, what defines a mass-timber project? 

The Oregon Department of Energy defines a mass-timber project as follows: When making a new material or building system, there are three essential steps: production, design, and construction. Each phase has its own needs and often calls for specialized engineering services and creative problem-solving. As more and more people use new materials and methods, research will be needed to ensure the work is done safely and correctly. The Sustainable Building Program is for research about building with mass timber (SBP).