The foundation requirements for a manufactured home can be found in the Permanent Foundations Guide for Manufactured Housing (PFGMH).
The lender must obtain a certification by an engineer or architect, who is licensed/registered in the state where the manufactured home is located, attesting to compliance with the PFGMH.
The lender may obtain a copy of the foundation certification from a previous FHA-insured mortgage, showing that the foundation met the guidelines published in the PFGMH that were in effect at the time of certification, provided there are no alterations and/or observable damage to the foundation since the original certification.
If the appraiser notes additions or alterations to the manufactured housing unit, the lender must ensure the addition was addressed in the foundation certification. If the additions or alterations were not addressed, the lender must obtain:
• an inspection by the state administrative agency that inspects manufactured housing for compliance; or
• certification of the structural integrity from a licensed structural engineer if the state does not employ inspectors.
For New Construction, the space beneath the house must be enclosed by a continuous foundation type construction designed to resist all forces to which it is subject without transmitting forces to the building superstructure. The enclosure must be adequately secured to the perimeter of the house and be constructed of materials that conform, accordingly, to HUD MPS (such as concrete, masonry or treated wood) and the PFGMH for foundations.
For Existing Construction, if the perimeter enclosure is non-load-bearing skirting comprised of lightweight material, the entire surface area of the skirting must be permanently attached to backing made of concrete, masonry, treated wood or a product with similar strength and durability.
For more information see Handbook 4000.1 II.A.1.b.iv(B)(5)(c)(ii) and II.D.5.c.available at https://www.hud.gov/program_offices/administration/hudclips/handbooks/hsgh
HUD’s Permanent Foundations Guide for Manufactured Housing (PFGMH) is available at https://www.hud.gov/program_offices/administration/hudclips/guidebooks/4930.3G