Mobile Home News & Manufactured Home News & Modular Home NewsHUD's Study OK's Homes for CoastsJuly 15, 2006
Acomparison by the Housing and Urban Development department has shown that HUD Code homes built to Wind Zone III specifications are equal in strength to site-built homes that withstand 130 mph winds.
HUD has established specific building codes in Florida for homes that are to be placed in Wind Zone III. It is interesting to note that some Florida manufacturers are building all their homes to meet the Wind Zone III code.
The executive director of the Mississippi Manufactured Housing Association had written HUD for clarification of the new building code requirements for housing on the Gulf Coast in the aftermath of Hurricane Katrina. William W. Matchneer III, HUD's associate deputy assistant secretary for Manufactured Homes and Regulatory Affairs responded in a letter:
"The emphasis that city and county officials have placed on 130 mph wind speed design requirements has apparently raised questions regarding the acceptability of HUD Code manufactured housing in these areas.
"The primary issue is how the HUD Code compares to the International Residential Code (IRC). The HUD Code Wind Zone III (coastal areas) requires homes to withstand a fastest mile wind speed of 110 mph, while the IRC uses a three-second gust of wind. Logically, most people would agree that a sustained wind of 110 mph is as tough a standard (or tougher) than a three-second gust of 130 mph. The HUD Code official came to the same conclusion.
"Comparing the wind design requirements provided for Exposure Category B in the IRC with HUD's wind design requirements for Wind Zone III and Exposure C in the table of Design Wind Pressures shows the design re- quirements in the HUD standards are comparable to the 130 mph design loads required by the IRC," the letter states.
"Therefore, manufactured homes produced to HUD's Wind Zone III requirements will perform equally to homes designed to resist a 130 mph three-second gust velocity under the IRC requirements. We have no reservation in recommending HUD Wind Zone III homes as fully suitable for placement in areas now designated for homes that meet IRC 130 mph requirements, and believe that manufactured homes should be considered on an equal basis."
In 2004, the Florida Manufactured Housing Association (FMHA) hired an engineer to compare HUD standard with the Florida Building Code. The conclusion of that study was that HUD's fastest mile 110 standard was virtually equal to, and in some cases exceeded, the Florida Building Code's three-second gust of 130 mph.
It should be noted that new home installation law in Florida is one of the most strict in the United States. The requirements for placing and installing the tie-down anchors, along with the new stabilizers, means those new home foundations are strong and will withstand strong winds. It needs to be repeated again and again that homes built after 1994 that were in the path of Florida hurricanes in 2004 and 2005 sustained little or no damage. Studies and surveys reported that new homes are built strong and compare favorably with site-built homes.
If you live in a home built prior to 1994, or in a home that has not had the tie-downs inspected in the past five years you need to do so NOW as we enter the hurricane season. You want to assure that all your tie-downs are sound and properly installed and I strongly recommend that if possible you should have the new stabilizer installed under your home. These stabilizers will anchor your home and prevent it from moving in any direction.
While you are contemplating inspecting and/or strengthening your foundation consider that your carport and screen room are more susceptible to high winds than your home. You might want to consider talking with a contractor qualified to strengthen your carport and screen room to withstand high winds.
Myths VS Reality
Myth: There is a traditional perception that
manufactured housing is more vulnerable to fire than other forms of
Reality: The fact is that manufactured homes are
no more prone to fire than homes built on site, according to an annual report
released by the Oklahoma State Fire Marshall's office.
have echoed the above statement made by the Foremost Insurance Company. A
national fire safety study conducted by the Foremost Insurance Company shows
that site-built homes are more than twice as likely to experience a fire than
manufactured homes. According to this study, the number of home fires is 17 per
1,000 for site-built homes, while only eight per 1,000 for manufactured homes.
What caused the improved fire safety of manufactured homes? Strict
construction standards. Foremost Insurance Company's marketing research
department took an in-depth look into the fire frequencies of manufactured
homes built before the advent of HUD (Department of Housing and Urban
Development) construction and safety standards, as well as homes built after
the standards went into effect in 1976. Foremost's researchers found that
post-HUD constructed manufactured homes burn less often and have lower fire
losses than pre-HUD homes.
Richard Wettergreen, Assistant Vice
President, Marketing Communications and Research at Foremost Insurance Company
said, "Manufactured homes are the only homes with a national building code. The
fire study indicates that HUD standards, adopted in 1976, have a positive
effect on fire safety in manufactured housing. When construction methods and
standards are considered, it appears to be a distinct and safe advantage to
live in a factory-built home. It's time the myth of high fire potential in
manufactured housing is laid to rest once and for all."
features of the HUD code include strict standards for flame spread and smoke
generation in materials, egress windows in all bedrooms, smoke detectors and at
least two exterior doors, which must be remote from each other and reachable
without passage through other doors that are lockable. Site-built homes are
required to have only one exterior door and no "reachability" requirement.
Another report entitled, "Fire Experience in Manufactured Homes," by
Dr. John R. Hall, Jr., which appeared in the May/June 1992 National Fire
Protection Association Journal, concluded that manufactured homes built to HUD
standards present a much lower risk of death and a significantly reduced risk
of injury in fires than units that were not built to HUD code requirements. The
study showed that in fires occurring between 1980 and 1989 that the fire death
toll per 100 fires in post-HUD homes is two-thirds to three-fourths lower than
pre- HUD homes. The fire injury is approximately one-third lower than pre-HUD
homes for the same period of time.
Even though the frequency of
manufactured home fires is less than that of site-built homes, the manufactured
home fire is usually more severe. "Manufactured homes tend to be smaller
properties than other homes... This means the median room sizes were much
smaller in manufactured homes." said Dr. John R. Hall, Jr. Fires can spread
more quickly in smaller-sized manufactured homes and site-built homes. Another
explanation of these more severe fires is that there is a significantly higher
percentage of manufactured homes in rural areas than in urban areas, while the
percentage of site-built homes is much higher in urban areas than in rural
areas. A fire in a home located in a rural area has a greater chance of
becoming a "total fire" because of the increased amount of time needed for fire
equipment to reach the home, since it may be outside a fire protected zone.
Myth: Manufactured homes are particularly vulnerable to
the destructive force of strong winds and tornadoes. Manufactured homes seem to
Reality: Hurricane Andrew struck the southern tip of
Florida and the Gulf Coast regions of Louisiana in late August 1992 with
devastating winds in excess of 150 miles-per-hour. The third strongest
hurricane ever to strike the United States, Andrew was designated a Category 4.
Thousands of homes, both site built and manufactured, suffered extensive damage
and destruction from the force of the storm.
Within weeks of the storm,
the manufactured housing industry endorsed appropriate improvements in the wind
resistance/safety of manufactured homes. After many months of effort by the
industry to negotiate proper improvements, the Department of Housing and Urban
Development (HUD) issued revisions to the wind safety provisions of the HUD
Code, which became effective July 13, 1994.
In areas prone to
hurricane-force winds (known as Wind Zones II and III, according to HUD's new
Basic Wind Zone Map) the wind safety standards require that manufactured homes
be resistant to winds up to 100 miles-per-hour in Wind Zone II and 110
miles-per-hour in Wind Zone III. In both of these zones, the standard for
manufactured homes is now more stringent than the current regional and national
building codes for site-built homes located in these wind zones.
important element in the adequate wind safety of a manufactured home is the
proper installation and anchoring of the home according to the manufacturer's
instructions. Installation standards are regulated on a state-by-state basis.
When properly installed and anchored, the manufactured home's wind resistance
is significantly improved. For each new manufactured home sold, the
manufacturer must include installation instructions to properly support and
anchor the home. This requirement is part of the wind storm protection
provisions of the HUD Code.
There is no meteorological or scientific
basis to thinking that manufactured homes attract tornadoes. The reality is one
of coincidence: most manufactured homes are located in rural and suburban
locations, where meteorological conditions favor the creation of tornadoes.
A tornado's deadly force does not selectively discriminate between the
site-built and manufactured home or "mobile home" (those built prior to the HUD
Code's implementation in 1976.)
In most of the country
(non-hurricane-prone areas), manufactured homes are built to withstand
sustained winds in the range of 70 miles-per-hour. Above this range, a
manufactured home will experience some form of damage. Only in the case of
severe weather, such as a tornado, are these areas likely to experience winds
in excess of 70 miles-per-hour.
It is estimated that approximately 40
percent of all tornadoes have winds in excess of 112 miles-per-hour. Tornadoes
can have winds in excess of 200 miles-per-hour in extreme cases. Current
building codes and practices, for either manufactured homes or site-built
homes, are not designed to withstand winds in excess of 110 miles-per-hour.
A direct hit from a tornado will bring about severe damage or
destruction of any home in its path. A tornado's deadly force does not
selectively discriminate between the site-built and manufactured home or
"mobile homes" (those built prior to the HUD Code's implementation in 1976).
If a manufactured home has a below-ground basement, the home's
residents should seek shelter there. If a home, site-built or manufactured,
does not have a below-ground basement, the residents should seek immediate
below-ground or other appropriate shelter from the storm's possible effects.
During a tornado warning, a tornado has been detected. Residents should seek
shelter in an interior room with no windows.
Myth: Manufactured homes are less energy efficient than
Reality: On October 24,1994 a new minimum energy
conversation standard became effective. The new energy standards are resulting
in lower monthly energy bills, a factor industry officials say will enhance the
affordability of manufactured housing and, perhaps, improve mortgage
underwriting terms. Improved home ventilation standards have also been adopted
in conjunction with the energy standards, a step that will improve indoor air
quality and condensation control in manufactured homes.
standards rely on computer modeling to identify the optimum cost-effective
conservation level for a home located in any one of three regions in the
nation. In developing the standards, the U.S. Department of Housing and Urban
Development followed Congress mandate to establish standards that "minimize the
sum of construction and operating costs" over the life of the home. This
emphasis on "lifecycle" energy costs is unique among national energy standards.
A new thermal zone map for manufactured housing identifies three
regions: the southeastern states are grouped from South Carolina to Texas in
Zone I; the mid-zone of the nation is grouped from North Carolina across to
California in Zone II; and the remaining northern part of the country is
grouped together in Zone III.
HUD's new standards require that
manufactured homes comply with one of three alternative options: design the
home's overall thermal efficiency to account for heat loss through the insulted
surfaces of the thermal envelope (better known as Uo-values) for three zones;
adjust Uo values with credits for high efficiency heating and cooling
equipment; or by totally redesigning the home with new innovative technologies
that use no more energy than published Uo values. Zone II, including Oklahoma,
requires a Uo of 0.096. These efforts are ensuring that manufactured homes
remain affordable, not only in start-up costs, but for the life of the home.
Myth: Manufactured homes do not appreciate in value
like other forms of housing. Instead, manufactured homes depreciate in market
value, similar to the way automobiles lose value each day.
While there is no one easy answer, recent data seems to suggest that
manufactured homes can appreciate just like other forms of housing.
Datacomp Appraisal Systems recently completed a study that looked at
185 manufactured homes in Michigan, comparing the average sale price when new
to the average resale price several years later. The study found the average
value of the home had increased by $190, from $26,422 new to $26,612 used. This
average figure is misleading, in that 97 of the homes increased in value by an
average of $2,985, while the remaining 88 decreased in value by an average of
The only accurate conclusion is that some homes appreciate and
some don't. Based on an analysis of 88,000 actual sales, Datacomp found that
there are specific reasons why some homes appreciate while other depreciate.
These reasons include:
The housing market in which the home is located, will have a significant
impact on the future value of the home.
The community in which the home is located, has a similarly significant
impact on the home's future value.
The initial price paid for the home.
The age of the home.
The inflation rate.
The availability and cost of community sites, which reflects the supply and
demand influences on the home's value.
The extent of an organized resale network, where an organized network will
usually result in homes selling for a higher price than in markets without such
an organized network.
The appreciation in value of manufactured homes
comes back to the old real estate axiom -- location, location, location. When
properly sited and maintained, manufactured homes will appreciate at the same
rate as other homes in surrounding neighborhoods.
Life of Manufactured Homes
Myth: Manufactured homes are not built as well as other
forms of housing. Manufactured homes do not last as long as site-built
Reality: Manufactured homes are built with virtually the same
construction materials and techniques as site-built homes. The only difference
is that manufactured homes are built in a factory environment, where building
materials are protected from weather damage and vandalism. Manufactured homes
are built to the federal Manufactured Home Construction and Safety Standards,
better know as the HUD Code, which is administered by the U.S. Department of
Housing and Urban Development (HUD).
The HUD Code is unique since it is
specifically designed for compatibility with the factory production process.
Performance standards for heating, plumbing, air conditioning, thermal, and
electrical systems are set in the code. In addition, performance requirements
are established for structural design, construction, fire safety, energy
efficiency, and transportation from the factory to the customer's home site. To
ensure quality, the design and construction of the home is monitored by both
HUD and its monitoring contractor, the National Conference of States on
Building Codes and Standards (NCS/BCS). The familiar red seal (the
certification label) attached to the exterior of a manufactured home indicates
that it has passed perhaps the most thorough inspection process in the
The Manufactured Housing Institute conducted a
study in 1990 to examine how long manufactured homes are habitable. The study
found that the habitable life of manufactured homes depends on the year of
manufacture. This habitable life has increased from 10.4 years for homes built
in 1945 to 55.8 years for homes shipped in 1964. This figure has held steady at
the 55.8 year figure through 1994, and is expected to remain at that level into