Cross-Laminated Timber - What & Why

Evaluating whether the Seattle Building Code should allow more height for buildings designed with cross-laminated timber.
  • What & Why
    Evaluating whether the Seattle Building Code should allow more height for buildings designed with cross-laminated timber.
  • Background
    Evaluating whether the Seattle Building Code should allow more height for buildings designed with cross-laminated timber.

What is Happening Now?

Cross-Laminated Timber (CLT) is an engineered product made of sheets of boards placed in layers perpendicular to one another in a manner similar to plywood. However, unlike plywood, CLT is made of thick layers of lumber with enhanced structural and fire-resistive performance.

The State of Washington has adopted Code standards that apply to the use of Mass Timber that are located on the State Building Code Council website.

Proposed Benefits

  • Carbon negative construction
  • Sustains local materials and industries
  • Reduces construction time
  • Cost competitive with concrete and steel
  • Clean and quiet construction process
  • Ideal for tight urban sites

The End Result

Seattle allows the use of the State-adopted standards for Mass Timber. We will be incorporating them into Seattle's Building Codes with an anticipated implementation date of March 15, 2021.