What Is a Permanent Foundation?
For lending purposes, a permanent foundation under a HUD-code manufactured home is one that meets HUD’s Permanent Foundations Guide for Manufactured Housing (PFGMH, HUD-4930.3G): built of durable materials (concrete, mortared masonry, or treated wood), site-built, with rated anchorage against uplift, overturning, and sliding; reinforced concrete footings below the maximum frost depth; and a continuous perimeter wall enclosing the space under the home. Screw-in soil anchors alone do not qualify as permanent anchorage.
Why the definition exists
FHA, VA, and USDA programs will only lend on a manufactured home as real property if the home is attached to the land the way a site-built house is. The PFGMH, published by HUD in 1996, is the standard those programs point to. It matters to your loan directly: a home on a qualifying foundation can be financed as real estate at mortgage rates; a home that falls short is generally limited to chattel (personal-property) lending at higher rates and shorter terms. The titling side of that story is covered in modular vs. manufactured.
The five criteria, in plain language
1. Rated anchorage against uplift and overturning
The connections holding the home down must have a rated capacity for wind or seismic forces, whichever controls at the site. This is the criterion that disqualifies the most installations: the common auger-type screw-in soil anchor, used alone, is specifically excluded. Anchors embedded in concrete, straps to wet-set anchors in a footing or wall, and other engineered connections can meet it.
2. Footings that are reinforced concrete, sized for the soil
Footings must spread the loads without overloading the soil — and to count as permanent, they must be reinforced concrete. Dry-stacked pads or unreinforced pours fall short of the definition even when they are carrying load adequately.
3. Footings below the frost line
The base of the footing must sit below the local maximum frost penetration depth so freeze-thaw cycles cannot heave the home. Frost depth is set by the local building authority; frost-protected shallow foundation designs per SEI/ASCE 32 are an accepted alternative in many jurisdictions.
4. A continuous perimeter enclosure wall
A continuous wall — bearing or non-bearing — must enclose the crawl space, separate it from backfill, and keep out vermin and water. Vinyl or metal skirting does not satisfy this; the wall is typically concrete, mortared block, or a framed wall on a footing.
5. Lateral stability in both directions
The system must also resist sliding — forces parallel and perpendicular to the home’s long axis — with rated connections. Longitudinal restraint is the piece most often missing from pier-and-anchor installations.
What this means for each foundation type
The category name doesn’t decide the outcome; the details do. A pier-and-block system can qualify when it has reinforced concrete footings below frost, rated (non-screw-in) anchorage, and a real perimeter wall. Crawl space, slab-on-grade, and basement foundations generally qualify when properly designed and built. Proprietary engineered systems qualify when they are listed and installed to the manufacturer’s instructions. The side-by-side rundown is in foundation types, compared. Wheels, axles, and towing hitch must be removed in every qualifying case.
Where this definition does and doesn’t apply
The PFGMH governs HUD-code manufactured homes only. For modular homes, Boxabl-class units, park models, and other structures, lenders sometimes borrow its vocabulary and ask whether a foundation shows the same “permanency characteristics” — but that is analysis by analogy, not a governing standard. Treating the two as interchangeable is the single most common error in loan files we review; the distinction is explained in the modular foundations guide.
How compliance gets documented
Lenders document PFGMH compliance with a certification letter from a licensed Professional Engineer who reviews the installed foundation — remotely from structured photo evidence or on site — and states whether it complies. Where it doesn’t, the letter identifies the specific deficiencies, which is usually a short repair list rather than a new foundation. How that process works, who asks for it, and what it costs are covered in foundation certification letters.
Frequently asked questions
Are screw-in ground anchors ever acceptable?
As the sole uplift anchorage for a PFGMH permanent foundation, no — they are specifically excluded. They remain code-compliant for standard Part 3285 installations outside government-backed lending, and they can be part of a qualifying system when combined with rated, engineered connections.
Is a permanent foundation the same as a Part 3285 code-compliant installation?
No. Part 3285 governs the physical installation; the PFGMH is a lending standard. A home can be installed exactly to Part 3285 — piers, straps, screw-in anchors — and still not meet the PFGMH.
Can my existing foundation be upgraded to qualify?
Often, yes. Typical retrofits are engineered anchorage replacing screw-in-only setups, reinforced footings, longitudinal ties, and a perimeter enclosure wall. An engineer can identify the shortest path from what exists to what qualifies.