Washington State

House of Representatives

Office of Program Research



Local Government Committee

ESB 5450

This analysis was prepared by non-partisan legislative staff for the use of legislative members in their deliberations. This analysis is not a part of the legislation nor does it constitute a statement of legislative intent.

Brief Description: Concerning the use of mass timber for building construction.

Sponsors: Senators Liias, Warnick, Ranker, Fain, Miloscia, Zeiger, Wilson, McCoy, Chase, Mullet and Frockt.

Brief Summary of Engrossed Bill

  • Requires the State Building Code Council to adopt rules for the use of mass timber products for building construction.

Hearing Date: 2/21/18

Staff: Yvonne Walker (786-7841).


The State Building Code.

The State Building Code establishes minimum statewide performance standards and requirements for building construction and construction materials in the state, consistent with accepted standards of engineering, fire, and life safety. The State Building Code is comprised of a number of model codes and standards, which are adopted by reference in the State Building Code Act (Act). Model codes and standards adopted in the Act include the International Building Code, the International Residential Code, the Uniform Plumbing Code, and the Uniform Plumbing Code Standards.

The State Building Code Council (Council), consisting of local government officials as well as building industry and public representatives, is responsible for adopting, amending, and maintaining, as appropriate, the model codes and standards adopted by reference in the Act. Amendments to the model codes and standards adopted by the Council are codified in the Washington Administrative Code. The Council regularly reviews and publishes updated editions of each model code and standard every three years.

Mass timber.

Mass timber is generally a term used to describe pre-engineered wood products that typically involve the lamination and compression of multiple layers to create solid panels of wood. Mass timber products are generally used to frame a building’s walls, floors and roofs and are seen as an alternative to steel and concrete products in the construction of buildings.

Summary of Bill:

The State Building Code Council must adopt rules for the use of mass timber products for residential and commercial building construction. The rules must take into consideration applicable national and international standards.

"Mass timber products" means a type of building component or system that uses large panelized wood construction. This includes cross-laminated timber, nail-laminated timber, glue-laminated timber, laminated strand timber, dowel-laminated timber, laminated veneer lumber, structural composite lumber, and wood concrete composites.

Appropriation: None.

Fiscal Note: Available.

Effective Date: The bill takes effect 90 days after adjournment of the session in which the bill is passed.