Bring the mass timber supplier and installer in during design, not after bid. WoodWorks recommends a delivery method with builder and specialty subcontractor input before bid and, on competitively bid public projects, bidding the supplier by the end of design development or 50% construction documents at the latest.
What WoodWorks recommends
The WoodWorks Mass Timber Cost and Design Optimization Checklists (May 2023) say that design-bid-build without builder and specialty subcontractor input before bid is neither a best practice nor cost-effective. They suggest construction manager at risk, design-assist, integrated project delivery, or design-build instead, and they recommend engaging the mass timber fabricator and installer early along with foundations, MEP and fire protection, and facade trades.
For publicly funded projects that will be competitively bid, the checklists recommend deciding on mass timber by the end of schematic design and early bidding the mass timber supplier at the end of design development or by 50% construction documents at the latest. The Mass Timber Construction Success Checklist from WoodWorks BC and Seagate Mass Timber (April 2025) adds that the procurement model should be chosen based on the team’s experience with mass timber. Sources verified October 22, 2026.
What early input settles
| Decision | Input needed | Where it ends up |
|---|---|---|
| Grid and panel sizes | Available panel sizes and spans from the likely manufacturers. | Grid plans, panel layouts |
| Penetrations | A deadline for coordinating openings, and the largest opening that may be cut on site. | MEP plans, panel layouts, specifications |
| Connections | Which connectors are installed in the shop and which in the field. | Connection details, specifications |
| Hardware scope | Which items, such as beam hangers and drag plates, the timber supplier provides and which the steel supplier provides. | Specifications, scope documents |
| Tolerances | Tolerances needed from concrete and steel trades where they meet the timber. | Interface details, concrete and steel specifications |
| Moisture management | A moisture management plan prepared with supplier input. | Specifications, construction plans |
| Engineering scope | Whether a timber engineer stamps the mass timber drawings, and who designs connections, the lateral system, and foundation anchorage. | Drawing list, general notes, contracts |
| Installation sequence | Delivery order, crane access, and bracing. | Construction schedule, temporary works plans |
Eight questions to settle before the supplier is chosen
- Delivery method. Does the contract model let the supplier and installer give input before the design is fixed?
- Bid timing. On a competitively bid project, is the supplier bid scheduled no later than the point WoodWorks recommends?
- Supplier-neutral grid. If the supplier is not known yet, is the grid sized to work for several manufacturers?
- Model workflow. If designers and the supplier will share models, have they agreed on software and workflow?
- Who installs. Will the general contractor or a subcontractor install the timber, and does the crew need training?
- Coordination deadline. Has the team agreed with the fabricator on a deadline for final penetration coordination?
- Design responsibility. If a specialty timber engineer designs some components, do the drawings say which ones?
- Preconstruction meeting. Will the supplier, installer, fabricator, design team, special inspector, and building official meet before work starts?
What arrives late without them
When the supplier joins after bid, the drawings may already contain grids, panel sizes, and connections that do not suit the manufacturer. Penetrations may still be uncoordinated, and the WoodWorks BC checklist notes that penetrations not fully coordinated before tender can delay fabrication. The WoodWorks inspection and observation paper also recommends a preconstruction meeting that includes the supplier, installer, and fabricator, held as soon as each has joined the project.
Whatever the timing, the drawings the supplier receives should agree with each other. The mass timber drawing coordination checklist lists what to verify before the fabrication release, and the project delivery methods guide compares the contract models.
Where Groundbook fits
Upload the architectural, structural, and MEP drawings with the relevant specification sections, and run a cross-discipline review. Groundbook flags potential disagreements, such as an opening shown on an MEP plan but missing from the structural panel layout, with links to each source sheet. Your team decides what each finding means for the fabrication package. Groundbook does not check structural capacity, fire ratings, or the fabricator’s model.