Heartwood Replication

Although timber is one of humanity’s oldest building materials, it is only recently reemerging as a material that can be deployed at scales long dominated by only steel and concrete. Through built prototypes, policy advocacy, rigorous fire testing, and comprehensive lifecycle assessment, mass timber has gained recognition as a safe, high-performance system. Today, it is approved for tall construction under the International Building Code, marking a major shift in how cities can be built.

However, as an emerging structural system, mass timber still lacks a deep catalog of precedents that clients and the construction industry can confidently reference. Our Heartwood Replication project builds on the success of Heartwood, the first Type IV-C tall timber structure, by carefully studying its design, detailing, and delivery process. From this foundation, we propose an adaptable, scalable model for low-carbon tall timber housing that provides a framework for future projects. It is time to build wooden cities.

In 2023 atelierjones completed Heartwood, an eight-story mass timber building in Seattle, Washington. Heartwood is the first project in the United States to take advantage of the new Type IV timber codes, which were adopted in part due to atelierjones’ research and advocacy.

Through the intensive design process for Heartwood, atelierjones and the rest of the project team have developed a mass timber building system that can be applied on a wide range of tall timber residential projects. This model represents an adaptation of Heartwood’s superstructure, expanded to a 12-story, Type IV-B configuration on a typical urban block.