Mass Timber Construction

Lighter and far more sustainable than concrete or steel – and valued for its natural beauty – mass timber construction is gaining ground as a primary structural material. Our experts have designed mass timber solutions for an array of building types, including commercial buildings, high- and low-rise residential, healthcare and labs, academic buildings, data centers, cultural and arts centers, sports and recreation, aviation facilities, and bridges and transportation infrastructure. 

Listen to our podcast: Mainstreaming Mass Timber

Benefits of Mass Timber 

Building with mass timber has significant benefits. Some are obvious: Mass timber is sustainable. It’s inherently lower in embodied carbon than concrete or steel. And it sequesters the carbon absorbed by the trees as they grew – an advantage that is magnified by timber’s ability to be reused in circular construction. 

When mass timber is left exposed, biophilia – the innate affinity people have with nature – becomes another virtue of the material. Its warmth, the soothing grain patterns, even its smell, contribute to a feeling of well-being for occupants. And leaving timber exposed cuts down on the time and expense of installing finishes. 

But mass timber has additional upsides during construction. Because timber is lighter than steel and concrete, it allows for more efficient substructures – often eliminating the need for costly and time-consuming deep foundation systems. This translates to less material used, reducing both cost and embodied carbon. And because timber elements are shop-fabricated to precise specifications, its on-site erection is much simpler than that of many other materials. Construction goes faster and can be performed by smaller crews. The resulting cost savings can significantly offset the material cost of mass timber, while faster speed-to-market timelines offer additional financial benefits.

Broad Experience, Deep Understanding, Enhanced Partnership 

With a portfolio that runs the gamut of project types – and experience with timber manufacturers around the globe – we’ve gained knowledge that enables us to act as a strategic partner. We can help stakeholders who may be new to timber construction to understand the nuances of building with it successfully. 

Our experts can guide conversations around initial costing, realistic schedules, how to approach insurance, and strategies for navigating code compliance and getting approvals for variances. We can also provide advice on the pros and cons of the many timber systems available – and whether an all-timber or hybrid system will best suit a particular project – as well as recommending reliable team members and helping evaluate bids.

Beyond Structural: Specialized Expertise for Better Mass Timber Design 

With more than 50 completed projects and dozens more underway, our structural designers have unmatched experience in the engineering of mass timber. But at Thornton Tomasetti, we have in-house expertise in a variety of disciplines that can dovetail with our structural work to streamline design and construction, make it easier to get code approvals and variances, and improve the performance and comfort of mass timber buildings. 

Carbon Quantification 

We developed Beacon, a carbon calculator tool that simplifies concept-stage embodied carbon analysis, providing quick, high-level feedback and clear data visualization of a structural system’s embodied carbon performance. 

Connection Design 

In mass timber structures, connection design may govern member sizing, geometry and system layout and must take fire protection requirements and fabrication tolerances into account. When our structural engineers also design a project’s connections, the entire system can be calibrated to account for these complex interactions from the start. We’ve worked hand-in-hand with contractors on real projects to develop a library of simple-to-erect, cost-effective connections that make for shorter design and construction schedules. 

Fire Engineering 

Our fire engineering services help mass timber projects move from promising concept to approvable, buildable reality. We use testing, advanced simulations and – when codes don’t adequately address the parameter of the project – performance-based fire design to protect life safety, support exposed-timber aesthetics, and bring taller or more complex visions to fruition. 

Special Inspections 

Thornton Tomasetti has certified inspectors who work hand-in-hand with the authorities having jurisdiction (AHJs) before and during construction to ensure there is an open line of communication between the design team, contractor, and city officials. This creates an added layer of quality control and allows the design team to address any on-site issues and to efficiently close out punch list items as they occur on-site.

Acoustics & Vibration 

The interaction between vibration and acoustic behavior in mass timber is very different from that of steel and concrete structures, and the science of managing sound and motion – so timber can be used for highly sensitive environments like laboratories or advanced manufacturing – is still developing. Our acoustics and vibration specialists combine structural dynamics, analytical modeling, and field testing to help teams optimize floor systems, connections, partitions, and façades to achieve practical, economical solutions. And we feed real-world results into our analytical models to make them more accurate, advancing understanding of high-performance mass timber design. 

GreenBox® 

We invented a prefabricated mass timber cassette floor system that is lightweight, extremely low in embodied carbon, and robust enough for use in long-span structures. GreenBox is made with a patented filling that provides tunable acoustic performance without topping slabs – making it easy to install, reconfigure, and eventually reuse.

Improving Mass Timber Procurement & Delivery 

We’ve learned through experience that it’s critical to involve the timber supplier early. A design-build or design-assist process helps the entire team design around real fabrication capabilities, available products, preferred connection strategies, shipping limits, and erection sequencing. The results are greater cost and schedule certainty and improved constructability. For public and institutional projects that are required to use a traditional design-bid-build process, though, success is still possible. But two elements are critical: designers who are experienced in mass timber and extra time, between the procurement phase and construction, to refine the design with the selected supplier. 

Advanced Timber Delivery (ATD) 

A typical mass timber project can require months of coordination between engineers, contractors, and third-party modelers after bidding. Our ATD service integrates that coordination into the design phase. Structural teams collaborate with in-house modelers and construction engineering experts to create a detailed, fully connected 3D model that can be shared with the manufacturer and construction team. This approach can shave months off construction schedules, provide better cost certainty during bidding, minimize fit-up challenges, and reduce conflicts and delays in the field. 

Pushing Boundaries & Setting the Standard in Mass Timber 

We see mass timber as a game changer for its combination of beauty, fabrication quality, speed of construction, low carbon footprint, and impressive fire resilience. Driven by our passion for better building, we’re committed to expanding what timber can do and setting new standards for what’s possible in structural design. 

We’re inventing and investing in new technologies that rapidly evaluate mass timber framing systems for strength, performance, and embodied carbon. Our tools are making design and analysis faster and easier, helping us show how timber can work for an ever-wider array of building types, sizes, heights, and locations.