UAD 3.6: Manufactured Housing as Data, Not Narrative
Most discussion of UAD 3.6 focuses on the new report layout, but for manufactured housing the real disruption sits in Appendix F-1 and GSE guideline B4-1.4-01: the end of narrative justification and the start of rigid, algorithmic data modeling. Under UAD 3.6, a manufactured home is no longer treated as a variation of a single-family home — it's its own distinct, primary building type.
Mandatory, structured verification
That shows up as hard-coded, mandatory verification: HUD data plates, certification labels, and permanent chassis status all become structured data fields rather than narrative notes. Appendix F-1 also forces the property to be deconstructed into independent datasets — dwelling exterior, unit interior, and site attributes — instead of one general "improvements" block. Because these are now discrete data points rather than prose, an unverified HUD tag or a classification error can trigger an automated eligibility failure before an underwriter ever opens the file.
Comparable sales and mixed-type properties
The standard also hardens comparable-sale consistency. Automated validation tools can now instantly flag a property-type mismatch in the sales grid, and if a manufactured home is compared to a site-built home, a narrative explanation in an addendum carries much less weight than before — the structured data itself has to bridge the gap, or the report gets flagged as high-risk.
The hardest case under UAD 3.6 is a mixed-type property, such as a site-built primary home with a manufactured ADU: the ADU must independently meet HUD standards and be classified as either a compliant improvement or personal property with zero contributory value — there's no more blending it into general commentary. And while the Cost Approach is often skipped for site-built homes, it remains essential for manufactured housing, since every physical characteristic now has to reconcile across both the Sales Comparison and Cost approaches. The bottom line: UAD 3.6 didn't make manufactured housing more complex, it made its existing complexity enforceable.