Here is a link to a 2018 ENERGY STAR technical bulletin :  How to Certify ENERGY STAR Modular Homes.  

I'll copy & paste a message as well.

From an ENERGY STAR semi-recent interaction:

“Importantly, a Rater must verify any requirements in the plant that will not be able to be verified on-site (i.e., because a feature will be concealed prior to shipment). Beyond the limited builder-verified items, it is not permissible for plant QC staff to perform inspections on behalf of a Rater or submit photos in lieu of a Rater inspection.”

And then here are two specific options we presented for making this happen:

“Modular plants are sometimes far from the home's installation site. To make things more difficult, several trips to a plant are often required to inspect the multiple modules that make up each home. Partners have used two strategies to overcome this challenge:

1. A Rater near the installation site can partner with a Rater located near the plant. RESNET standards permit coordination between multiple Raters, though the arrangement must be approved by the Rating Provider who will ultimately submit the home to the RESNET registry. In this case, communication and coordination between the Raters is critical.

2. If a plant expects to regularly produce ENERGY STAR certified homes, a quality control staff member can become a Rater themselves. Again, the Rating Provider will need to approve of coordination between this Rater and the Rater at the installation site.”

No matter who your provider is, it is important to get them to approve the coordination of the alternate rater method and any applicable QA.

Anyone else with experience in this is welcome to chime in.

Bryan