Mass Timber Construction: The Developer’s Guide for Office Buildings

Office spaces demand versatility and functionality from Owners, Developers, Investors, and occupants alike. A growing number of A/E/C professionals are meeting those needs by building with mass timber construction, due to its efficiency and unique appeal. Understanding this historic material’s reemergence, and its advantages, can help you deliver innovative, safe, and captivating office environments from mass timber on your next project.

Mass Timber Prototypes

Timber Meets Technology

The rise of mass timber projects in the United States has led to a new way of thinking about high-density space programming. As occupants and businesses grow increasingly keen on connectivity, as well as sustainability in engineering design and construction, Developers are reimaging timber and its applications in the A/E/C industry. Real estate investment firms are aiming to design buildings that embody both connectivity and sustainability inside and out. Goals for these built spaces include timeless design, state-of-the-art technology and communication coverage, as well as locations near public transportation hubs for easy access by occupants and tenants.

By blending timber, transit, and technology, Owners, Developers, and their construction partners can create built spaces that are financially and environmentally feasible, as well as more inviting for occupants. These creative projects give a sense of thoughtfulness and forward thinking. In turn, they typically lease quickly, with their distinct appeal, access to mass transit centers, and indoor connectivity. A fully leased building also underscores an aesthetically pleasing, high-performing built environment achieving its full value and potential.

Mass Timber Projects

The first mass timber office building in the US that incorporated timber, transit, and technology was developed from ideas of creative, timeless architecture. Per building codes, the seven-story, 220,000-square-foot, timber frame office building was created from Type IV Heavy Timber. In order to design a building that would outperform similar models, as well as transform the city’s market and skyline, Developers on the project assembled a conceptual design and construction team for the mass timber prototype, T3 Minneapolis. They invested more project budget upfront in reliable building materials and systems, with a “buy it nice or buy it twice” mentality, to avoid potential expenses due to replacing equipment or fixing errors. After opening in November 2016, the building leased quickly, creating a business incentive for mass timber projects.

Inspired by the success of T3 Minneapolis, the project team sought to improve upon the building’s designs with their second mass timber project, T3 West Midtown in Atlanta, Georgia. The project was completed in September 2019 with the assistance of experts in mechanical, electrical, and plumbing engineering design from Jordan & Skala Engineers.

Sustainable Construction

Mass timber projects require resourcefulness and superb attention to detail from design to construction, and the T3 buildings were no exception. Therefore, the Developers and their partners harnessed the unique versatility and undeniable efficiency of mass timber to successfully complete both projects. The buildings were made from construction-grade, dowel-laminated 2×8 panels composed of spruce, pine, and fir combined.

The trees utilized for the Dowel Laminated Timber panels in the project had beetle infestations on the West Coast, but they were given new life as the timber for T3 Minneapolis. By repurposing a nonviable resource, the building promoted sustainability in engineering design and construction from start to finish. The beetles had punctured the trees, killing them and leaving them at risk of becoming forest-fire hazards; however, using mass timber decreased that risk and increased the Atlanta project team’s efficiency, as timber can be prefabricated in-factory. The building’s timber core further emphasizes mass timber’s versatility, strength, and ability to manage structural loads.

For T3 West Midtown, glued-laminated (glulam) columns and beams were made from young-growth timber sourced in Austria. The timber was then shipped to the team’s architectural partner, StructureCraft, Inc., in Vancouver, British Columbia.

Mechanical Systems

The T3 projects are prime examples of successful mass timber developments. In addition to timber itself being a more sustainable construction material, T3 West Midtown’s energy consumption is more efficient than previous models of timber frame office building developments, due to its mechanical systems. For example, the building’s energy recovery unit (ERU) uses outgoing exhaust air to precondition outside air coming in, resulting in decreased energy use.

The lightness of T3 Minneapolis’ almost all-wood building combined with its concrete core reduced the seismic load significantly. Because timber is strong and flexible enough to manage structural loads, the Developers selected a timber core for T3 West Midtown. This decision also saved them the time of pouring concrete and allowing it to dry; projects that can be constructed faster, can be leased faster. Timber cores are effective, save time during construction, and help create more interesting, welcoming, and humanizing spaces than concrete, as well.

To help ensure comfortable, spacious tenant areas at the Atlanta project, the mechanical engineering experts at Jordan & Skala utilized multi-zone, chilled water air handlers. Attractive ductwork inside the building remains exposed, alongside exposed structural wood beams, while a Texas multi-zone unit keeps noisey air valves in the core. T3 West Midtown’s noise criteria levels are notably better than more traditional systems, due to the unique sound absorption of timber combined with the multi-zone unit.

Benefits of Mass Timber Projects

Mass timber builds present Owners, Developers, and their project partners with significant advantages. Not only is wood sustainable and reliable, it also contributes to savings, in terms of both cost and time.

Speed and Cost

On construction sites, time is money. There are schedules to stick to and deadlines to meet. However, many professionals in the A/E/C industry have found that mass timber allows for faster construction than concrete, in addition to increased efficiency and sustainability in engineering design and construction phases. Due to its prefabrication capabilities and block-like assembly, building with mass timber contributes to cost savings from the time saved.

Wood has one-fifth the weight of concrete; this relative lightness makes it a suitable material for both columns and beams. Timber can be assembled similar to how building blocks are put together, which distributes weight evenly and helps navigate structural challenges. Mass timber also allows for cost savings in labor, too, since onsite contractors typically only need to assemble the delivered material.

On project sites utilizing primarily concrete or steel, contractors often find themselves vying for use of equipment to pour concrete or situate steelwork. When mass timber is the main component, major equipment, such as cranes, are used solely for wood, eliminating competition and wait times for equipment. Efficiency is key on construction sites; contractual obligations must be met according to defined schedules. The construction process is streamlined, providing a significant cost savings in terms of labor, when the major equipment on a project site is dedicated solely to timber construction.

Holes in the wood for vertical pipes and conduits can be pre-engineered in-factory, which also saves time; once the timber arrives onsite, all that remains is assembly. Mass timber construction is similar to how building blocks are assembled to make a standing structure; the panels, beams, columns, etc. are simply stacked and arranged, as opposed to being poured or made onsite.

Sustainability

In addition to timber’s remarkable speed and comparatively lower costs, it has proven to be a more sustainable construction material than cement. The wood used to construct mass timber buildings can be regrown, whereas steel and concrete demand much more energy and resources. Because all steel is now reused, utilizing it for construction purposes requires reforming or reshaping preexisting steel.

Construction-grade timber is typically sourced from young-growth trees instead of old growth, which saves forests and is equivalent to eliminating carbon dioxide emissions from 996 cars for 6 months. If the trees aren’t used within 5 years of dying from beetle infestations, they are made available for sustainable construction or as fuel for controlled burns; otherwise, the nonviable timber risks becoming a forest-fire hazard. As a renewable resource that also helps maintain existing forests, mass timber construction enables Owners, Developers, and Investors to build more sustainable office spaces.

Appeal, Aesthetics, and Performance

Timber lends itself to timeless architecture that performs well, demonstrates continued viability, and humanizes both buildings and city skylines. Projects with mass timber can deliver impactful spaces from the outside in. In lieu of conventional ceilings, exposed structural wood beams and piping appeals to contemporary aesthetics and younger generations. Sheet metal ducts can also be used as an attractive accent material to complement exposed elements and save time.

The practical advantages of mass timber are as distinct as its aesthetic appeal in built environments. Buildings that combine timber, transit, and technology align closely with LEED ideals and signal forward thinking and thoughtfulness to younger generations. Timber alone absorbs sound well and helps Owners and Developers achieve better noise criteria levels than both concrete and steel. Fire safety testing has also increased the pragmatic appeal of this material. Flammability tests have established that burns are predictable; wood’s natural char layer makes large, compressed pieces of timber difficult to burn. These findings prove that mass timber is safe and that it does not increase fire hazards.

Units in timber buildings can lease quickly, due to their unique appeal; like T3 Minneapolis, these buildings can approach full occupancy soon after opening, contributing to a faster return on investment.

Current Mass Timber Trends

Humans have been building with wood for thousands of years. With such strong historical use, mass timber construction has reemerged and is on the rise. In the US, these projects are being seen more frequently on the west coast, especially in Oregon and Washington, where sustainable construction materials are easily obtained from Canada.

Additionally, the unconventional ceiling designs often seen in timber projects, such as those with exposed structural wood beams, piping, and conduits, are becoming more desirable in today’s market. Increased testing has also proven that wood is a safe, reliable material that promotes sustainability in engineering design and construction. As a result, many building codes are being updated to allow for more and taller mass timber buildings, including office spaces.

Timber cores have also been proven safe for load bearing, due to their building-block-style assembly. That leaves the decision to utilize a timber or concrete core to the project’s climate, schedule, or funding, as opposed to safety. As mass timber construction increases, Owners, Developers, and their partners can gain significant flexibility from sustainable construction materials, including wood.

Projections for Mass Timber Construction

The proven advantages of mass timber in construction point to it being an enduring option in the A/E/C industry. Fire and safety testing results have established its safety and viability, paving the way for more mass timber builds. Previous height and weight restrictions, particularly due to the weight that must be supported on the roofs of timber-made offices, are being updated to reflect the outcomes of rigorous safety tests.

Owners and Developers should anticipate continued, if not greater, traction in upcoming years. Use of mass timber is increasing nationwide, especially in Denver and Chicago, as traction has a history of progressing from the West Coast to the East Coast. Building codes are also being updated to allow for taller mass timber buildings. The inviting look and feel of timber, coupled with its advantages as a sustainable construction material, nearly guarantee its ongoing use and increasingly versatile applications.

Best Practices with Mass Timber

Even as mass timber becomes more common, it’s important for Owners and Developers to collaborate with experienced project partners, like Jordan & Skala Engineers, who understand how to maximize the advantages of sustainable construction materials and avoid missteps that can impact scheduling and costs.

These projects need coordination, defined schedules, and clear contractual obligations among trusted partners. Mass timber often requires design partners with knowledge of specific terms and dimensions to incorporate into drawings for identifying points of penetration, using whole pieces of wood, or similar. To avoid jeopardizing the integrity of the material or the design, contractors and partners must drill in the correct zones on beams and walls where there will be tension or holes cut. Seasoned structural engineers should also be consulted to pre-cut wood flooring from whole pieces, as opposed to parts of wood, to help ensure both speedy completion and aesthetics. Due to the equipment and material demands of mass timber, experienced partners should be consulted to identify opportunities that will promote a return on investment without impacting the project’s long-term viability.

From their experiences with mass timber projects, as well as sustainability in engineering design and construction, Jordan & Skala’s team of engineers have found solutions to help Owners, Developers, and their partners navigate the nuances of mass timber construction.

• Weather conditions can have a significant impact on project sites, as wood swells when it comes into contact with water, including that in humid air. Skilled project partners can help identify proper mechanical infrastructure to manage interior humidity and microbiological growth once the building has been built. To maintain a structure’s integrity, timber should also be water treated.
• Incorporating energy-efficient equipment into mass timber projects should be done by engineering partners with the experience to select the most effective systems for the design. For example, the T3 West Midtown team selected an ERU, which brings in outside air using an enthalpy wheel; that air is preconditioned by the outgoing heating/cooling exhaust air, resulting in lower energy consumption.

To ensure a building’s efficiency, its system must provide sufficient outside air and adequate air changes per hour to exhaust the proper amount of air. Experienced engineers, like those from Jordan & Skala, can help ensure that outside air handlers are sized properly and that adequate air changes per hour, or ACPH, occur. This inhibits virus and bacteria growth, which improves indoor air quality (IAQ) and promotes healthier indoor environments amid the covid-19 pandemic. Experts at Jordan & Skala Engineers emphasize the role of seasoned design professionals in helping to create healthy spaces and improve indoor air quality, particularly with the advent of covid-19.

• Indoor connectivity is another challenge to be considered for mass timber builds, including a timber frame office building. Reliable communication technology and coverage are critical for offices, especially those built with the T3 mindset, where technology accessibility plays a pivotal role. Skilled partners can work with providers to find local circuits, determine how they can be accessed, and negotiate the capital infrastructure needed for high-speed coverage in timber-built office spaces. Best-in-class technology services can earn mass timber projects a Platinum WiredScore rating, contributing to these buildings’ appeal and promoting the integration of naturally beautiful, timeless design with modern functionality.

Final Thoughts

Mass timber presents Owners, Developers, and Investors with a safe, reliable option to meet growing market demands for buildings that can be constructed efficiently and leased quickly. With skilled design partners and engineers, like those at Jordan & Skala, mass timber projects can be efficiently coordinated and executed to produce buildings that experience long-term success. Contact the experts at Jordan & Skala Engineers for creative planning, design, and coordination that helps ensure a return on investment with mass timber buildings that are both environmentally and financially sustainable.

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Learn more about the history, best practices, & projections for offices behind mass timber construction by downloading our guide.