Solid wood and steel can provide a low carbon structural system option to help reduce the use of concrete, which tends to be an energy and emissions intensive material. Developers interested in using hybrid steel framing and hardwood flooring have guidelines and recommendations with help from the recent “Design Guide 37: Hybrid Steel Frames with Wood Floors”, a publication available from the American Institute of Steel Construction.
Written by environmental consultancy Arup, the guide offers information on how hybrid steel frame buildings and hardwood floors can combine low carbon carbon with the strength of steel and solid wood.
The building industry produces 50% of the planet’s greenhouse gas emissions, 20% of which come from materials and their manufacture. Solid wood and steel can reduce the use of high energy and emission materials in developing buildings.
Hybrid steel frame buildings with solid wood floor panels allow for longer beam spans and reduced column size compared to comparable solid wood post and beam construction. This makes it an attractive option for market-oriented spaces such as office buildings. Cross-laminated timber (CLT) flooring can replace carbon-intensive concrete slabs. Its ability to be left exposed in certain places also eliminates the need for additional architectural finishes. Plus, both are pre-fab, which means better quality control and quick construction.
“Massive wood and steel hybrid systems have enormous potential to advance the building industry’s sustainability goals and reduce global emissions,” said Michelle Roelofs, Associate Director at Arup. “Lighting the pathways of this hybrid topology will help accelerate the use of wood in place of more carbon-intensive materials.”
Arup’s hybrid steel-wood design for the Houston Endowment headquarters in Texas reduced its carbon footprint by nearly 50% compared to an original cast-in-place concrete design. The original schematic design of the Houston Endowment headquarters was reconsidered to address significant structural costs and an extended construction schedule.
Design Guide 37 is intended for structural engineers with no experience in mass timber or hybrid construction, as well as architects, developers and owners who may be considering hybrid structures. The guide includes references to relevant International Building Codes (IBCs) and standards, as well as advice from industry and international sources. The design guide applies to allowable construction types as defined by IBC 2021.