The single largest key to successful modular construction is coordination drawings, and the repetitive process of review prior to the building set. This process literally ties the Off-Site building process with the On-Site!
Background: Teams to a modular job must be clear about who will produce coordination drawings, and to what level of detail they will be taken.
There are different levels of “Plans and specifications”, those that form the base contract with your owner, or “permit sets of drawings” are often far from fabrication or “shop level” drawings. Shop drawings are where all the action is for a successful modular project.
Step 1: Be sure to request that factory drawing set includes photos and detail of typical mate-line connections.
(These are sent to Modular Construction Manager (the role Triumph plays) for their approval on behalf of the Owner.)
Step 2: Ensure that factory production teams in the plant are responsible to create as-built documents during construction for more details such as marking on approved plans were exactly on the structure that specific connections (electrical, HVAC, etc.) will be placed. Ask factory for as-built records for items like siding completion or other complex facades, parapets, roof screens, roofing details when kissing up to the existing building on-site, or other unique features.
(Note: For some clients, hard copies neatly marked up by hand by the team and then scanned into PDF format for sharing is typical, other clients may require the mark-up to be converted into a blue beam, CAD, or Revit as-built version of record. It is important that this level of as-built is requested pre-contract with the factory because it costs more. (FYI Triumph always requests the highest level of coordination drawings on our projects.)
Step 3 : Focus on “ship loose”. Packing lists of materials that will be shipped loose, and accompany the load (mainly for seaming and stitching at mate lines ) are also generated by the project management and production team.
(Note: The best modular factories will in addition to having a Project Manager dedicated to the project, will also identify a separate QC manager in the plant who verifies final ship loss, prior to transporting the loads. A form is utilized, that lists each material, a description for its use, the quantity required, and where it gets stored in the modules for shipment or other means of delivery, with dates for delivery if shipped separately.)
Step 4: Plan to have the site contractor visit the modular plant and carry this cost upfront.
(Note: The visit is timed either prior to the factory disconnecting the modules to prepare for shipment (in the case of a “build in place” or “static build “ modular approach ), or prior to volumetric mods going on the assembly line (in the case of an assembly line approach ). At a minimum, this visit should include the field supervisor with the factory field supervisor who is planned to follow the modules to the site.)
Bonus information: On complex jobs, with heavy customization of pre-engineered designs and complex systems the project team should send sub-contractors in each trade (mechanical, electrical, and plumbing at a minimum) to visit the modular factory to inspect and learn about connections points they will be making on-site.
Conclusion: Following these processes, and carrying costs for them at the outset of the project will eliminate surprises in the field and greatly minimize excessive scope overlap or scope gaps at site.
Credit: Lee Bachman, of Modlogic Inc. contributed greatly to this post.
Good luck !