According to the FHA Website here are the manufactured home guidelines required for getting a FHA loan:  

A Title I loan for a manufactured home requires one of the following:

• A certificate label attached to the home, or
• A label verification letter. Obtain a label verification letter by visiting the website of the HUD approved contractor, the Institute for Building Technology and Safety (IBTS)
  

A Title II loan requires all of the following:

• A certificate label or label verification letter.
• The placement of the home on a permanent foundation that complies with the Permanent Foundations Guide for Manufactured Housing (PFGMH).
• A certification from a licensed professional engineer verifying compliance with the PFGMH.

The most common permanent foundation errors delaying the approval of an FHA-insured loan for a manufactured home are:


• The foundation footings that are not set below the frost line
• Dry-stacked piers are used instead of required piers with mortared head and bed joints
• The use of ground anchors - because FHA doesn't accept these as a permanent attachment
• Any permanent foundation lacking an engineer's certification, even if it complies with all other elements
• Vinyl skirting used as an enclosure that doesn't meet ALL of the following FHA requirements:
• Properly enclosed crawl space with a continuous permanent foundation-type construction (similar to a conventionally built foundation, i.e., concrete, masonry or treated wood)
• Designed to resist all forces without transmitting the building superstructure to movements or effects caused by frost heave, soil settlement, or the shrinking or swelling of expansive soils.
• Adequately secured to the perimeter of the unit to exclude entry of vermin and water
• Allowance for proper ventilation of the crawl space

          The most common errors that may cause a delay are:

• The foundation footings are not set below the frost line
• The use of dry-stacked piers are used instead of the required piers with mortared head and bed joints
• Ground anchors are used, because FHA does not accept these as a permanent attachment
• Any permanent foundation lacking an engineer's certification, even if it complies with all other elements
• Vinyl skirting used as an enclosure, that doesn't meet ALL of the following FHA requirements:
  
  
  1. Properly enclosed crawl space with a continuous permanent foundation-type construction (similar to a conventionally built foundation, i.e., concrete, masonry or treated wood)
  2. Designed to resist all forces without transmitting the building superstructure to movements or effects caused by frost heave, soil settlement, or the shrinking or swelling of expansive soils
  3. Adequately secured to the perimeter of the unit to exclude entry of vermin and water
  4. Allowance for proper ventilation of the crawl space

Disclaimer: Bennett Appraisals does not promote any program or products we just appraise SFR properties  in Whatcom, Skagit and Snohomish Counties WA.  All information deemed to be accurate but not guaranteed.