February, 2004
Inspection News and Views from the American Society of Home Inspectors

Modular or Manufactured Home?


The phone rings. It’s a real estate agent saying she needs an inspection done on a house 25 miles outside the city. Even when she adds, “It’s a modular home,” I have no reason to believe there will be anything unusual about this job.

When I arrive at the house, the client and a talkative homeowner are waiting for me. The homeowner offers that he bought the home a few months ago as an investment and now wants to sell it. He reports what he’s done to ready it for re-sale, and when the client mentions “modular home,” he confirms that it is.

You can imagine the surprised looks on all their faces when a short time later I tell them it is not a modular home, it is a mobile or manufactured home.
Although manufactured homes are taxed as personal property, in this case I was told the MLS, the bank and the county tax records all had it listed as real property (a modular home on a permanent foundation)! I can only guess how this happened, but I do know that it can be embarrassing at the least and possibly expensive for any home inspector who does not know the difference.

Defining the difference

A modular home is built in a factory in modules that are shipped to a site and assembled. A modular home is built to the applicable building codes. It has a wood floor structure, and the overall appearance is not much different from that of a stick built home, other than where the modules are joined together.

A manufactured home (aka mobile home, trailer or doublewide) is also built in a factory, but transported to a site on its “own wheels.” A manufactured home is built according to the requirements of the U.S. Department of Housing and Urban Development (HUD) rather than building codes. A manufactured home always has a steel chassis that cannot be removed. The modern version often does not resemble what many of us associate with a mobile home, thereby presenting the opportunity for misidentification.

Identifying a mobile home  On the outside

As you walk around what you believe to be a mobile or manufactured home, keep a keen eye for a metal identification tag approximately 2"x 3" in size. It will have a number, and will identify the house as having been manufactured under HUD standards.  A doublewide manufactured home will have an identification tag on each section. The flimsy metal roofs on many older manufactured homes have been covered with EPDM roofing or coated with some type of sealant. Today’s modern versions almost always have shingles on the roof, and the roof feels firm to walk on.

There may be a shallower pitch to the roof than that of a stick built home, but that may vary. On a doublewide home, there is often a vertical trim strip on each end that hides the juncture where the two sections are attached.

Sometimes you can see where the tow tongue was removed after arrival on site. Often the brick skirt or underpinning will stick out beyond the home’s siding, and the drain plumbing may be of smaller diameter than that which is used on other homes.

You may notice 1/4" vent stacks instead of the 1/2" common on modern stick built homes.  Eave venting is usually constructed much differently than what is seen on a conventional home, and stoops or porches are often not attached, but rather free-standing.

On the inside

There is usually a data tag at the electrical panel, or sometimes inside a kitchen cabinet or a bedroom closet, with the date the home was manufactured and information about the HVAC system. This is not to be confused with the data sticker often found in a kitchen cabinet of a modular home, which provides information about inspections. I cannot remember ever seeing a manufactured home with an attic, and most had cathedral ceilings.

The doors, both interior and exterior, are much thinner in comparison to a stick or a modular home. Often, the sinks are smaller, and the plumb-ing fixtures and toilets are usually different. Wood paneling was the norm for the finished walls of older manufactured homes, but modern units typically will have a 3/8" drywall panel with what appears to be textured wallpaper covering it.  

Under the home

You may find that the brick foundation is nothing more than a brick skirt and that the home actually sits on cement blocks. In a manufactured home, this floor frame is always steel. If the wheels have been removed, you typically can see where they were once attached. You should see a series of metal tie-down straps. Specifications and requirements for straps may vary, but typically, if you don’t see tie-down straps, it should be reported as a defect.

Floor insulation on a manufactured home will have a plastic barrier, usually black in color, completely concealing the insulation. Often, it appears to be hanging down. It’s  commonplace to find high weeds and/or remnants of vegetation indicating it has been parked there.

Need to know the basics

This is a less-than-exhaustive list of ways to identify a manufactured home, but it provides the basics for taking that first important step — confirming that it is one so the correct criteria can be used for the inspection. While there’s a lot more to learn about this type of inspection, my recent experience with the manufactured home masquerading as a modular one demonstrates the importance of knowing the basics about every type of home. The unexpected is always just a phone call away.
John Cranor is the owner of Cranor Home Inspections in Glen Allen, Va., and he serves as the chair of the ASHI Technical Committee.


Pit Set Adds to Challenge

If it’s sometimes difficult to distinguish a manufactured home from a conventionally framed home, the installation technique known as a ‘pit set’ doesn’t make it any easier. Most manufactured homes are set on a site that’s simply been leveled to remove vegetation and create an even bed. Their floors are always several feet above the surrounding ground, giving them a distinctive look that can be a tip-off to their true nature. Pit set manufactured homes, however, are placed over an excavated pit that forms a crawlspace below grade. The home’s floor is only a few inches above the ground around it, contributing to the appearance of being a conventionally constructed building with a below-grade foundation. Some manufactured home communities require pit setting, as do some lenders.
These homes tend to experience more problems with water accumulation in their crawlspaces, so when inspecting them, be sure to look extra-carefully at the surrounding grade to ensure surface water doesn’t flow into the pit.

—James Katen, ASHI Member