4C2B: Century-scale Carbon-sequestration in Cross-laminated Timber Composite Bolted-steel Buildings

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Boston, Massachusetts
Project Term:
12/06/2022 - 12/05/2025

Critical Need:

HESTIA addresses the need for implementing carbon removal strategies by converting buildings into carbon storage structures. HESTIA is also important for nullifying embodied emissions. The majority of these emissions are concentrated at the start of a building’s lifetime and locked in before the building is ever used. This upfront emissions spike equals 10 years of operational emissions in a building constructed to meet standard code, but increases to 35 years for more advanced, higher operating efficiency buildings, and more than 50 years for high-efficiency buildings operating on a lower carbon intensity grid. These time horizons go beyond 2050 climate targets, which means embodied emission reduction strategies are a high priority.

Project Innovation + Advantages:

Northeastern University will dramatically accelerate the replacement of carbon-intensive concrete structural components by developing a new structural system comprised of deconstructable and reusable steel frames with cross-laminated timber (CLT) floor diaphragms. Diaphragms are structural elements that transmit lateral loads to the vertical resisting elements. CLT diaphragms can store up to 50% of their weight in biogenic carbon. Building design for deconstruction (DfD) of steel+CLT allows for direct reuse of structural members, reduces new steel emissions, and enables storage of biogenic carbon in timber for 100+ years, which the typical 40–50-year lifespan of building materials is unable to accomplish. The team will also address the technical risks and uncertainties around DfD steel-to-CLT and CLT-to-CLT connectors as well as apply innovative advanced manufacturing techniques for CLT to use local timber, expanding U.S. manufacturing potential while reducing carbon emissions from the transportation of materials.

Potential Impact:

HESTIA projects will facilitate the use of carbon storing materials in building construction to achieve net carbon negativity by optimizing material chemistries and matrices, manufacturing, and whole-building designs in a cost-effective manner.


HESTIA technologies will reduce the carbon footprint of the built environment.


Building materials and designs developed under HESTIA will draw down and store CO2 from the atmosphere.


A variety of promising carbon storing materials are being explored and commercialized for building construction. Currently these materials are generally scarcer, cost more per unit, and/or face performance challenges (e.g., flame resistance for biogenic carbon-containing materials). HESTIA seeks technologies that overcome these barriers while nullifying associated emissions and increasing the total amount of carbon stored in the finished product.


ARPA-E Program Director:
Dr. Marina Sofos
Project Contact:
Prof. Jerome Hajjar
Press and General Inquiries Email:
Project Contact Email:


University of Massachusetts, Amherst
Simpson Gumpertz & Heger Inc.
Swarthmore College
OPAL Build

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