Prefabrication used to belong to the big national GCs and the hospital builders. That is no longer true. Mid-market commercial contractors are racking corridor racks, bathroom pods, and exterior wall panels in shops that used to be just warehouse space. The labor market did this as much as the technology. You cannot staff three sites with the same electricians you had in 2019, so you move the work to a bench.
Start With the Assemblies You Already Repeat
Do not begin with a full modular building. Begin with the thing you install on every job: a restroom wet wall, a typical patient headwall, a storefront mullion, or a corridor MEP rack. Measure the hours you spend on it in the field today. If a shop can cut that in half and the design is stable, you have a candidate. One assembly done well will teach your PMs more than a tour of someone else’s factory.
The Shop Needs a Schedule, Not Spare Time
A prefab shop that runs on leftover labor will miss every delivery. Assign a lead, a weekly slot on the lookahead, and a delivery date that the superintendent treats like a concrete pour. If the design is not frozen, do not cut. The fastest way to poison prefab inside your company is to send a rack to a site that has already moved the corridor.
Transportation and Access Are Part of the Design
A rack that does not fit the hoist or the site gate is scrap. Involve the superintendent in the shop drawing, not just the detailer. Confirm turning radius, laydown, and the crane or forklift that will set it. On urban infill, that conversation happens at pursuit, not after fabrication.
Quality Control Moves Upstream
You cannot punch a rack after it is hung over a lobby. Photograph connections, pressure tests, and labels before the truck leaves. Give the owner and the inspector a chance to see the first unit in the shop. That visit prevents the “we have never accepted this” conversation on install day.
What to Tell the Owner
Owners hear “prefab” and think cheaper. Sometimes it is. Often it is faster and more predictable, with a similar first cost. Sell the schedule certainty and the inspection quality. Show them the hours you took off the critical path on the last job. Mid-market owners will fund a shop setup if you can point to a date you hit because the racks were ready.
Prefabrication is now a staffing strategy for contractors who do not have a national balance sheet. Pick one repeated assembly, give the shop a real schedule, and inspect it before it ships. Do that a few times and prefab stops being a trend and starts being how you bid.
Keep the Union and Open-Shop Questions Honest
Prefab changes where the hours happen. If you work under a labor agreement, talk to the hall before you move a rack to a shop. If you are open shop, still be clear with your own crews about what work is leaving the site and what work is staying. Surprise is how you lose the people you still need for install. A short meeting beats a rumor that you are “replacing the field.”