Give Your Subcontractors the Correct Modular Plans

This is a story about the first time one of my customers made a big mistake when acting as their own general contractor.  They forgot to give one of their subs the factory’s updated and approved modular plans.  Although this happened 27 years ago, I remember it like it was yesterday – mostly because of how cleverly it was solved, and not by me.

Starting with Modular Plans Drawn by the Customer

Warren and Debbie had just sold their existing home.  Warren’s father had gifted them a building lot in a local town with a very good school system.  Before they started shopping for a modular home dealer, they designed a custom 28’ x 38’ two-story.   Their modular plans were very straightforward.  Warren had done a lot of research on modular construction and knew about having a “marriage wall” where the modules joined front to back.  His modular plans had no bumpouts, not even for a fireplace chase, so his home was a true rectangle.
After they selected my company, we spent the next two months working with the factory to get the modular plans just the way they wanted them.  Since modular factories typically build their 28’ wide plans 27’6 for delivery purposes, the factory had adjusted the modular plans a couple of inches here and there.  Warren and Debbie also made several relatively minor tweaks to the plans.

The Customers’ Responsibility for Getting the General Contractor the Correct Modular Plans

When they were happy with the final modular plans, and had closed on their construction loan, they applied for their building permit and updated their subcontractors about the likely arrival of the modules.  These tasks were their responsibility because they had decided to act as their own general contractor.  They were on a tight budget and wanted to save the 15% to 20% a GC would add to the subcontractors’ charges.  Fortunately their families knew several local subs.
As soon as they received their permit, they authorized me to place their home in the factory’s production schedule.  They also asked their excavator to begin the site work, including digging the hole for the foundation.  As soon as the excavator began his work, they scheduled the foundation to be poured – first the footings then the walls.

The final factory approved modular plans for the foundation.
The customer is responsible for giving the subcontractors the final factory modular plans and instructing them to discard the previous copies they’ve received

When I called Warren to ask how his subs were doing, he said everything was going well.  He was especially pleased with the foundation because it was a perfect 28’ x 38’.  I paused and asked if he didn’t actually mean it was a perfect 27’6 x 38’.  I heard a gasp followed by silence.   He said, “Oh no!  I never gave my foundation guy the factory’s foundation drawing, and I completely spaced out on the change to the width.”  I asked him how the sub knew what to pour.  Warren explained that he started shopping for subs before the factory had drawn its modular plans, so he had given the foundation sub his original 28’ x 38’ plans.

If You Can’t Fix It, Feature It

Fortunately Debbie came up with a great solution.  As they often say in construction, “if you can’t fix it, feature it”.  She had wanted a large deck off the back of the house and now she was going to get it – one that was 38’ long and ran across the entire back of her home.  Since the foundation wall had been poured 10” thick, the modules would sit on the inner half of the rear wall and the deck would rest on the outer half.  The local inspector also required some structural support just inside the foundation wall (lally columns spaced 8’ apart, etc.)  Once the deck was built, the foundation looked as if it was intentionally poured to support it.

My Advice

One lesson I learned from this experience is to remind those customers who are hiring their own subs to give the subs a copy of the final factory modular plans.  In addition, I tell my customers to instruct their subs to discard the previous copies they’ve received.  I usually take this one step further and recommend that my customers get the old modular plans back from their subs so they don’t mistakenly use them.  If you’re going to serve as your own GC, you’ll want to remember all three steps of this advice.
For more information about ensuring that your subcontractors use the correct modular plans, see The General Contractor’s Responsibilities for Building a Modular Home and Designing a Modular Home in my book The Modular Home