Although technically a "manufactured" home, the VERMOD company in Wilder, Vermont has been making NetZero ready one-story "modular" homes as replacements for old manufactured/mobile homes since 2013.
Last year Vermont was the first in the nation to replace a very old mobile home park with a 14 unit NetZero modular home park for low income renters.
VERMOD's modular homes are built similar to manufactured homes, but are put on a permanent, frost-protected foundation, rather than a steel beam chassis on concrete blocks. Their HERS ratings are in the 35-45 range, depending on model.
See vermodhomes.com for more information. Read the news section for more on various VERMOD homes set around the state (and out of state). Look at Contacts for more information. Efficiency Vermont can provide more technical information, and they are in the process of getting DOE ZERH certification.
buildsmartna.com is making Passive type or could be net "O". We just did a 7.5" sip panel with 2x4 stud wall inside for wires and pipes then dry pack fiber in stud wall. blower door number before finishing sheet rock is 256 CFM at -50 PA. The panels fit on a truck and crane in place with butter type seal between panels. All windows and doors are sealed before sent to job side. Truss type roof , if 16" center can support PV
looks like a good product to improve the building envelope to PASSIVE levels. The housing industry is suffering from a labor shortage and not meeting the demand for affordable housing nationally.
Here is a video I find entertaining on site built HERS rated homes