Oregon mass timber library runs sprinkler pipe and lighting through split laminated beams

The 95,000-square-foot Multnomah County library was completed in May 2026. Its frame uses 300 CLT panels, 1,200 beams and 96 columns, according to Architectural Record. Holst and fabricator Timberlab built it to Type IV, the heavy-timber construction type, so the wood could stay fully exposed with no added fire treatment. Fortis Construction was the general contractor, and PAE Engineering did the MEP and fire protection design.

Exposed timber leaves sprinkler mains and conduit few good routes. They often end up behind drywall, bored through beams or hung from them. Dave Otte, Holst's managing principal on the job, told the magazine this is "the bane of mass timber." Holst's fix was to build the beams as split pairs and run pipe and lighting in the reveal between the two halves.

The sprinkler contractor objected that some of the pipe bends could not be made, Otte recalled. The project's mechanical engineer then built a full-size mock-up from parts bought at a hardware store nearby and showed that they could. The other services are out of sight: HVAC equipment sits in the basement, and ductwork runs between the first-floor ceiling and the second-level floor.

Holst designed the library with Adjaye Associates through design development. In July 2023, after sexual harassment allegations against David Adjaye surfaced, library director Vailey Oehlke dropped his firm, and Holst's Brittany Shreiner became design principal. Value engineering later cut a corner tower, a fiberglass sunscreen around the building, a cantilevered outdoor amphitheater above the garage entry, and a spiral stair in stainless steel. The magazine did not report what the split-beam detail added to timber or sprinkler costs.