A model of a 42 story wood building designed by Skidmore Owings Merrill architects sat tantalizingly at the right side of the stage, as panels of architects, engineers and designers at a Chicago conference recapped and forecast the rising fortunes of taller wood buildings.

Built of cross laminated timber panels -a kind of horsey plywood - the buildings eschew stud frame construction. With thick panel walls there are no 2x4 studs for cabinetmakers to locate in hanging their work. Likewise hardwood flooring is laid down differently. And the list goes on for trim, moulding, panels, mantels - etc. I couldn't wait to ask the panel about it.

The event is one of a half dozen around the U.S. sponsored by WoodWorks, a wood industry effort to promote the use of CLT, or Cross Laminated Timber, in building design and construction. WoodWorks itself is funded by a mix of government agencies and industry groups, including the Softwood Lumber Board - a U.S. forestry marketing program; Forestry Innovation Investment of British Columbia; Natural Resources Canada; and the U.S. Forest Service Forest Products Lab. 

Sponsors and exhibitors at the event included KLH and Nordic, two firms that make CLT used in the tall wood building construction; along with construction materials suppliers Sauter Timber, Simpson StrongTie, Structurlam, and MiTek.

While registration seemed to have faltered just two weeks ago, a last minute influx packed the house, at a meeting site along one of Chicago's architectural treasures, South Michigan Avenue. Architects, it turns out, are really busy - and very interested in this subject.

The program kicked off with a reception last night detailing a competition for U.S. developers, institutions, organizations and design teams to create a practical  taller wood structure. The prize is $2 million. Similar programs in by Canada's Wood WORKS! have yielded structure designs that recently have been built, or will be built soon. Canada Wood WORKS! Oscar Faoro is Project Manager, U.S. Tall Wood Building Prize Competition.

Tall wood buildings have been capturing the imagination of architects and engineers who see them as an opportunity to reduce costs and lessen the carbon footprint of buildings. Some designers are pushing the limits of existing codes - both construction and fire safety -  with buildings of five stories or so of light wood-frame or heavy timber construction.

Following ongoing research and testing, much of it detailed at this WoodWorks symposium, North America will be able to follow Australia, Austria, the United Kingdom and others, which already have built eight- to ten-story buildings made from cross laminated timber  or composite wood-concrete and wood-steel building systems.

An interesting pair of luncheon presentations at the WoodWorks "Toward Taller Wood Building" symposium included a presentation on the Kingsgate eight-story CLT apartment building, which used KLH panels cut on a giant CNC. Nordic's Jean Marc detailed the development of a Canadian tall wood building competition submission.

Much of the symposium centered on engineering and building code issues - including fires resistances (oddly, wood buildings burn slowly) and seismic safety (there are no formal measurement standards for wood building's earthquake resistance).

At the end of series of presentations, I was finally able to ask about building out interiors on these tall wood buildings. My question led to answers from many of the panelists, which can be summarized thusly:

  • Building trades work inside a tall wood structure takes one fourth time required for a normal construction
  • Interiors are so much simpler to work on - nearly all the components are wood - that traditional project tiems over-estimate dramatically the labor and time involved.

Rebecca Holt, of Perkins + Will, who presented "A Survey of International Tall Wood Buildings," (along with M. Urb) spoke for several panel members in noting that the appeal of the wood surfaces and structural components in the CLT and timber frame wood structures is so strong that architects want to reveal as much as possible of the wood engineeering. "The feel of the interior is completely different than with steel and concrete."

A presentation by Rune Abrahamsen, Lillehammer, Norway, covered a "14-story Apartment Under Construction in Norway – TREET from an Engineer’s Perspective," 

Sponsors of the Chicago program, KLH and Nordic, firms that manufacture CLT used in the construction of tall wood buildings, also spoke about some of their customers projects, including a LEED wood building in the U.K. (KLH), and projects in Quebec Province in Canada (Nordic).

Wood frame building
Located on the south campus of the University of British Columbia in Vancouver, the wood-framed Sail Condos is six-stories tall, and has 172 units. It was designed by the Rositch Hemphill Architects.

Other projects covered included:

• A completed 10-Story Apartment in Australia: Forté from an Owner/Developer Perspective, Daryl Patterson, Lend Lease Australia

• The London Trend toward Tall Timber Projects: Bridport House, Stadthaus and Whitmore from a Planning Commission Perspective, Vincent Stops, Hackney Planning Commission

• 98-Foot Tall North American Wood Research Facility: Wood Innovation Design Centre from a Tenant Perspective, Guido Wimmers, University of Northern British Columbia

• Canadian Tall Wood Competition Summary, Robert Jones, Natural Resources Canada

• Feasibility of Taller Timber in an Urban US Market: Pacific Northwest Cross Laminated Timber (CLT) Feasibility Report,Joseph Mayo, AIA, LEED AP, Mahlum Architects

• Joe Mayo w Chris Duvall of Mahlum Seattle feasibility study on Taller Timber structures WoodWorks Chicago.

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