Mass timber construction has revolutionized the architectural landscape, offering a sustainable and innovative alternative to traditional building materials. Engineered wood products like cross-laminated timber (CLT) and glulam beams have paved the way for skyscrapers and complex structures that were once thought impossible with wood alone. This article discusses the top 20 tallest mass timber buildings globally, exploring their design, engineering feats, and environmental impact. From the iconic Ascent MKE in Milwaukee to the groundbreaking HOAS Tuuliniitty in Finland, each building showcases the beauty, strength, and versatility of mass timber, ushering in a new era of eco-friendly architecture.

Also called engineered wood or composite wood, Mass Timber includes a range of derivative wood products which are manufactured by binding the strands of wood to form composite material. These products are engineered to precise design specifications, which are tested to meet national or international standards and provide uniformity and predictability in their structural performance. Engineered wood products are used in a variety of applications, from home construction to commercial buildings to industrial products. The products can be used for joists and beams that replace steel in many building projects. The term mass timber describes a group of building materials that can replace concrete assemblies.

There are four main categories of mass timber:
• Cross-Laminated Timber (CLT): Several wood plank layers (typically odd-numbered) are glued together with each layer perpendicular to the one above and below it.
• Nail-Laminated Timber (NLT): One of the oldest forms of mass timber, NLT uses nails to bind wood layers together.
• Dowel-Laminated Timber (DLT): Wood planks are drilled and then joined using long wooden dowels.
• Glued-Laminated Timber (Glulam): Layers of wooden planks are attached with glue to form Glulam beams and columns.

Mass timber offers several advantages over traditional timber, including increased compression strength and flexibility. This allows for its use in load-bearing elements like structural panels, beams, and posts, opening doors for large-scale timber construction projects.

The Top 20 Tallest Mass Timber Buildings in the World

1. Ascent MKE, Milwaukee (USA): This 284-foot-tall building currently holds the title of the tallest mass timber building globally. Designed with sustainability in mind, Ascent MKE uses glulam beams and columns, CLT floor panels, and sustainably-sourced wood throughout most of its construction.

2. Mjøstårnet, Brumunddal, Norway: Standing at 280 feet tall, Mjøstårnet was once the world’s tallest timber building. This all-timber structure incorporates glulam for load-bearing elements and CLT for balconies, stairwells, and elevator shafts. Locally sourced timber minimizes transportation emissions.

3. HoHo Wien, Vienna, Austria: This 275.6-foot mixed-use building combines timber and concrete. Roughly 74% of HoHo Wien’s construction utilizes sustainably-sourced wood, primarily for walls, ceilings, and the interior support structure. Precast concrete complements the timber framework, forming the building’s core.

4. HAUT, Amsterdam, Netherlands: HAUT utilizes pre-fabricated CLT panels for its load-bearing structure and timber planks for walls, floors, and ceilings. Much of the exposed wood interior creates a warm and inviting atmosphere. To ensure stability, the basement, foundation, and cores are built from concrete.

5. Sara Kulturhus Centre, Skellefteå, Sweden: Inspired by Skellefteå’s long history of timber construction, this 238.8-foot-tall center incorporates locally-sourced CLT and glulam, with steel elements for reinforcement. Prefabricated CLT modules stacked between elevator cores and supported by a glulam beam and pillar framework form the high-rise section. The low-rise section features a similar timber frame with CLT shear walls and cores.

6. De Karel Doorman, Rotterdam, Netherlands: This 229.7-foot building exemplifies both mass timber construction and adaptive reuse. A light timber and steel construction was added on top of the existing building’s foundation and columns, creating an additional 16 floors without compromising structural integrity.

7. 55 Southbank Boulevard, Melbourne, Australia: This 228-foot building is another example of adaptive reuse. One of the world’s tallest vertical mass timber extensions, it showcases Australia’s first CLT extension project. Ten new floors were added using lightweight timber elements on top of the existing concrete-and-steel structure.

8. Abro, Risch-Rotkreuz, Switzerland: This 167-foot building is part of a campus designed with sustainability as a driving force. Timber was chosen for its eco-friendly properties, as wood naturally sequesters carbon. The building features a wood-and-concrete composition.

9. Hyperion, Bordeaux, France: Named after the world’s oldest living tree, this 187-foot tower is the tallest mass timber building in France. It utilizes glulam, LVL, and CLT for various structural elements, with concrete used for the core and the first three floors for structural reasons.

10. Eunoia Junior College, Bishan, Singapore: The first mass timber high-rise educational facility in Asia, this 183.7-foot college features …aluminum-clad CLT panels for the facade and a glulam-and-concrete composite hybrid system for the floors. Extensive use of prefabricated CLT elements expedited construction and significantly reduced construction site waste. Due to limited space, the college boasts a unique vertical layout with two interconnected learning towers housing classrooms, a library, an indoor sports hall, and dance studios.

11. Rundeskogen Hus B, Sandnes, Norway: This 177-foot tower is part of a tree-inspired residential complex. Originally planned as an all-timber project, it ultimately became a timber-and-concrete hybrid. Mass timber serves as a secondary framework material and clads the fins of the building’s star-shaped concrete core. This design creates the illusion of roots branching from a central trunk, minimizing the project footprint and preserving views for neighboring houses.

12. Brock Commons Tallwood House, Vancouver, Canada: This 174-foot student housing building is the tallest mass timber building in Canada. It utilizes prefabricated engineered timber for the frame, concrete for the foundation and cores, and steel for some structural and roofing elements. The lightweight timber elements enabled faster construction with less waste compared to traditional methods.

13. Treet, Bergen, Norway: This 160.8-foot building, aptly named “The Tree,” honors Norway’s timber-building tradition. Clad in steel and glass on the exterior, Treet features a glulam timber framework, CLT balconies, elevator shafts, and staircases, with prefabricated living modules for its 14 stories. Power floors and concrete slabs provide stability and manage wind loads.

14. Lighthouse Joensuu, Joensuu, Finland: This 157.5-foot building, functioning as a residential structure for students, is a testament to subtle timber construction. The entire framework, except for the ground floor, is built from wood. LVL timber is used for wall frames, while CLT forms the intermediate floors. Plasterboard or stone cladding conceals the wooden surfaces to comply with building codes.

15. 25 King, Brisbane, Australia: This 153.5-foot office building is considered an all-timber structure. From the second floor upwards, the building utilizes a glulam column and beam structure, with CLT wall cores, ceilings, and floor planks. Diagonal glulam braces provide additional lateral support for the facade. Concrete is only used for the basement and ground floor to prevent moisture and insect damage.

16. HOAS Tuuliniitty, Tapiola, Finland: This 144.4-foot building holds the record for the tallest modular wooden building globally. Built using prefabricated solid-CLT volumetric modules, the construction process significantly minimized on-site waste. A thick concrete slab provides structural stability at the base. Wood-against-wood joints further enhance the structure’s resilience against strong winds. The building houses 165 student apartments across its 13 stories.

17. Origine, Quebec City, Canada: At the time of its opening in 2017, Origine held the record for the tallest mass timber residential building globally. Overcoming challenges posed by building codes, the project successfully employed mass timber for all thirteen floors. Black spruce CLT forms the load-bearing walls, shear walls, flooring, and roof, while glulam timber beams and posts create the structural system. Today, Origine houses 92 apartment units and continues to inspire tall-timber construction in Canada.

18. Sensations, Strasbourg, France: This 124.6-foot building stands as the tallest all-timber building in France. The frame and envelope are composed entirely of wood, with concrete limited to stairs, the ground floor, and specific regulatory requirements. CLT construction dominates the building, featuring a glued-laminated beam-to-beam structure. Wood cladding extends up to the fourth floor, transitioning to aluminum panels above.

19. Rundeskogen Hus C, Sandnes, Norway: The shorter counterpart to Hus B, this 121.4-foot building mirrors its neighbor’s base structure and utilizes mass timber on the fins radiating from its core. The design maximizes views and sunlight throughout the year. Public green spaces surround the complex, connecting existing buildings to nearby forests.

20. Waratah, Bella Vista, Australia: This 118.11-foot building features a cross-laminated timber structure, pushing the boundaries of mass timber high-rise design. Approximately 2,700 square meters of sustainably sourced CLT were used to create a curved structure, a departure from the typical “boxy cube” design. Glulam columns support large glazing elements in the lobby, and exposed timber is a prominent feature throughout the interior.

Conclusion
Mass timber construction represents a significant shift towards more sustainable and innovative building practices. The growing number of mass timber buildings around the world showcases the immense potential of this material.

Here are some key takeaways:
• Environmental Benefits: Mass timber offers a sustainable alternative to traditional materials like concrete and steel. Wood acts as a carbon sink, storing carbon dioxide throughout its lifespan. Sustainable forestry practices ensure the responsible sourcing of timber, minimizing environmental impact.
• Faster Construction: Prefabricated CLT panels and other mass timber elements enable faster construction times compared to traditional methods. This reduces labor costs and minimizes on-site disruption.
• Seismic Resilience: Mass timber exhibits surprising strength and flexibility, making it suitable for earthquake-prone regions. The lightweight nature of wood reduces seismic loads on the building foundation.
• Improved Aesthetics: Exposed wood interiors create a warm and inviting atmosphere. The natural appeal of wood offers a refreshing alternative to concrete and steel aesthetics.
• Regulation and Codes: Building codes and regulations are continuously evolving to accommodate mass timber construction. The success stories mentioned above demonstrate the growing acceptance of mass timber as a viable building material.

The future of construction seems to be embracing the potential of mass timber. As technology advances and regulations adapt, we can expect even taller and more innovative mass timber buildings to grace our skylines.