Model Manufactured Home Installation Standards, 59338-59395 [07-5004]

Agencies

• DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT

[Federal Register Volume 72, Number 202 (Friday, October 19, 2007)]
[Rules and Regulations]
[Pages 59338-59395]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 07-5004]



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Part II





Department of Housing and Urban Development





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24 CFR Parts 3280 and 3285



Model Manufactured Home Installation Standards; Final Rule

Federal Register / Vol. 72, No. 202 / Friday, October 19, 2007 / 
Rules and Regulations

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DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT

24 CFR Parts 3280 and 3285

[Docket No. FR-4928-F-02]
RIN 2502-AI25


Model Manufactured Home Installation Standards

AGENCY: Office of the Assistant Secretary for Housing--Federal Housing 
Commissioner, HUD.

ACTION: Final rule.

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SUMMARY: This final rule establishes new Model Manufactured Home 
Installation Standards (Model Installation Standards) for the 
installation of new manufactured homes and includes standards for the 
completion of certain aspects necessary to join all sections of multi-
section homes. The National Manufactured Housing Construction and 
Safety Standards Act of 1974 requires HUD to develop and establish 
Model Installation Standards after receiving proposed installation 
standards from the Manufactured Housing Consensus Committee (MHCC). HUD 
received and reviewed the MHCC's recommended proposed model 
installation standards and published a proposed rule for public 
comment. Based on HUD's review of the comments that were submitted, 
including those from the MHCC, a number of revisions to the proposed 
rule have been made in this final rule. This final rule also 
incorporates certain amendments to definitions contained in the 
Manufactured Home Construction and Safety Standards (MHCSS) that are 
affected by definitions provided in the Model Installation Standards.

DATES: Effective Date: The effective date for this final rule will be 
October 20, 2008. The date of approval by the Director of the Federal 
Register for incorporation by reference of certain publications listed 
in this rule is October 20, 2008.

FOR FURTHER INFORMATION CONTACT: William W. Matchneer III, Associate 
Deputy Assistant Secretary for Regulatory Affairs and Manufactured 
Housing, Office of Manufactured Housing Programs, Department of Housing 
and Urban Development, 451 Seventh Street, SW., Room 9164, Washington, 
DC 20410; telephone number (202) 708-6401 (this is not a toll-free 
number). Hearing-or speech-impaired individuals may access this number 
through TTY by calling the toll-free Federal Information Relay Service 
at (800) 877-8339.

SUPPLEMENTARY INFORMATION:

I. Background

    On April 26, 2005, HUD published in the Federal Register at 70 FR 
21498 a proposed rule that would establish Model Manufactured Home 
Installation Standards (Model Installation Standards) for new 
manufactured homes, as required by the National Manufacture Housing 
Construction and Safety Standards Act of 1974 (42 U.S.C. 5401-5426) 
(the Act). The Act gave the MHCC responsibility to develop and submit 
to the Secretary proposed Model Installation Standards. The MHCC's 
proposal was provided to HUD in September 2004. The Department agreed 
with most of the proposal, and thoroughly involved the MHCC in the 
process by which the proposed rule for the Model Installation Standards 
was developed prior to its publication in the Federal Register.
    There were a total of 101 commenters on the April 26, 2005, 
proposed rule. Seventy-seven of the commenters were from the industry, 
including manufacturers, component suppliers, retailers, installers, 
realtors, trade associations, and community operators. Nineteen 
commenters came from the government, including HUD-approved Primary 
Inspection Agencies and State Administrative Agencies. Finally, four 
commenters were individual consumers and consumer groups and one was a 
private code organization.
    Among the recommendations most often made by the commenters were: 
(1) To codify the Model Installation Standards in existing part 3280 
rather than new part 3285, in the belief that the installation 
standards would thereby become ``preemptive'' of state and local 
installation standards; (2) to make the installation standards 
applicable to secondary or other subsequent installations of 
manufactured homes; (3) to include provisions assuring that HUD will 
consult with the MHCC on future changes to the installation standards; 
(4) that manufacturers' installation instructions be considered as 
evidence of compliance with the Model Installation Standards; (5) that 
the installation standards apply to the joining together and close-up 
of multi-section homes and to certain other aspects of on-site 
completion that HUD had originally treated as part of the construction 
process. HUD has given these subjects particular attention in preparing 
the final rule.

II.A. Analysis of Public Comments--Part 3280

    Comment: Sec.  3280.302 Definitions. Two commenters wrote that the 
proposed definition of anchoring system should include forces on the 
foundation and anchorage systems, which may actually control the design 
in some instances.
    HUD Response: The definition of anchoring system includes a 
reference to the forces that are required to be resisted by foundation 
and anchorage systems.

II.B. Analysis of Public Comments--Part 3285

Subpart A--General

    Comment: Sec.  3285.1(a) Scope. The Model Installation Standards 
should be preemptive of state and local requirements.
    HUD Response: HUD has concluded that a plain reading of Sections 
604(d) and 605 of the Act indicates that Congress did not intend for 
these Model Installation Standards to be preemptive of more stringent 
state or local government requirements, only that they establish 
minimum national requirements for the installation of manufactured 
homes. This conclusion is strengthened by the statement from then-
Chairman Jim Leach during his section-by-section comments on the floor 
of the House, that ``the bill would reinforce the proposition that 
installation standards and regulations remain under the exclusive 
authority of each state.'' (Dec. 5, 2000, 146 Cong. Rec. H11987). In 
earlier floor remarks, then-Ranking Member John LaFalce said, ``States 
that wish to have their own installation standards may continue to do 
so, as long as they provide protections comparable to the model 
standards.'' (Oct. 24, 2000, 146 Cong. Rec. H10685). HUD therefore 
believes that Congress has permitted any state that chooses to operate 
its own installation program to enforce installation standards more 
stringent than these Model Installation Standards, provided that those 
standards otherwise offer protection that equals or exceeds the minimum 
protection established by these Model Installation Standards.
    Comment: Sec.  3285.1(a) Scope. The Model Installation Standards 
should be codified under 24 CFR part 3280, Manufactured Home 
Construction and Safety Standards.
    HUD Response: Contrary to the views expressed by some commenters, 
preemption authority can only come from Congress, and no decision that 
HUD could make regarding the codification of these Model Installation 
Standards could increase or diminish that authority. However, as 
indicated above, HUD believes there is good reason to conclude that 
Congress did

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not intend to extend preemption authority to these Model Installation 
Standards.
    In any event, HUD has chosen, as a matter of administrative 
necessity, to codify these Model Installation Standards, as in new part 
3285 of 24 CFR, in order to maintain the clear distinctions the Act 
makes between installation and construction. The regulatory structure 
that Congress has given HUD for enforcement of these Model Installation 
Standards is entirely different from the enforcement authority it 
previously gave HUD for the federal MHCSS. As HUD reads the Act, 
section 613 (42 U.S.C. 5412) and section 615 (42 U.S.C. 5414), the 
principal sections requiring notification and correction of defects, do 
not apply to these Model Installation Standards. As HUD reads the Act, 
the primary enforcement authority for these Model Installation 
Standards is instead limited to section 605 (42 U.S.C. 5404) itself, 
which not only provides more limited authority for these Model 
Installation Standards, but also adds entirely new requirements 
regarding the licensing and training of installers.
    Given these fundamental differences between the installation and 
construction and safety programs, publication of these Model 
Installation Standards in new part 3285 of 24 CFR will best allow HUD 
to maintain the regulatory separation necessary to administer two such 
different programs.
    Comment: Sec.  3285.1(a) Scope. Work associated with the joining 
together and close-up of sections of multi-section homes and certain 
aspects of on-site completion should be considered as installation of 
the home and not as construction.
    HUD Response: Under the final rule, work necessary to join sections 
of a multi-section home, such as work identified in Subparts G, H, and 
I of the installation standards, and work associated with connecting 
exterior lights, ceiling-hung light fixtures, or fans, as identified in 
Subpart I, are treated as installation, and therefore is subject to 
these Model Installation Standards and any future requirements of the 
installation program regulations. Accordingly, close-up work completed 
on-site would require inspection under the Manufactured Home 
Installation Program Proposed Rule published in the Federal Register on 
June 14, 2006. However, features such as penetrated hinged roofs, high-
pitched hinged roofs, and eave construction will remain subject to the 
MHCSS and the Procedural and Enforcement Regulations in 24 CFR part 
3282.
    In early drafts of these Model Installation Standards, HUD treated 
all activities associated with close-up as part of construction of the 
home and, as such, subject to the MHCSS and the manufacturer's 
certification label. However, HUD recognizes that installers, not 
manufacturers, typically perform close-up work. Therefore, HUD has 
concluded that the Model Installation Standards provide the best 
opportunity to address close-up activities and concerns.
    Further, under the final rule, home purchasers generally will look 
to installers or retailers who often employ or contract with installers 
to perform home installations, to remedy close-up problems that are not 
the result of inadequate or incorrect manufacturer instructions or of 
production errors that have resulted in the sections of the home not 
fitting together properly.
    Comment: Sec.  3285.1(a) Scope. Compliance with the Manufacturer's 
Installation Instructions should be accepted as compliance with the 
Model Installation Standards. Several commenters also recommended the 
section be rewritten as follows: ``The manufacturer's installation 
instructions shall apply under any of the following conditions where 
they do not take the home out of compliance with the Federal 
Manufactured Housing Construction and Safety Standards: (1) To items 
not covered by this standard; (2) Where the manufacturer's approved 
installation instructions provide a specific method of performing a 
specific operation or assembly; (3) Where the manufacturer's approved 
instructions exceed this standard.''
    HUD Response: Sec.  3285.1(a) of the final rule recognizes that the 
Model Installation standards serve as the basis for the manufacturer's 
installation instructions and accepts those instructions for 
compliance, as long as they meet or exceed the minimum requirements of 
the Model Installation Standards and do not take the home out of 
compliance with the MHCSS. However, the methods for performing 
operations that are included in a manufacturer's installation 
instructions will be enforced by the Department, in their entirety.
    Furthermore, the final rule requires that manufactured home 
manufacturers include installation instructions with each new home. The 
instructions must be approved by a Design Approval Primary Inspection 
Agency (DAPIA) and must provide protection to the residents of 
manufactured homes that equals or exceeds the protections provided by 
the Model Installation Standards.
    Comment: Sec.  3285.1(a) Scope. The Model Installation Standards 
should be applicable to subsequent installations beyond the initial 
siting and placement of the manufactured home.
    HUD Response: It is HUD's position that Congress intended the 
installation standards to be applicable only to the initial 
installation of new manufactured homes, as indicated by references in 
Section 623(g) of the Act to the date of installation and by the 
definition of ``purchaser'' as the first purchaser in Section 603 of 
the Act. A very small percentage of manufactured homes are ever 
relocated after the initial siting and placement of the homes. The 
Manufactured Home Procedural and Enforcement Regulations encourage 
states to establish procedures for the inspection of used manufactured 
homes and for monitoring of the installation of manufactured homes 
within each state (Sec.  3282.303), thus indicating the regulations' 
intent to place the supervision of re-installments in the hands of the 
states.
    The final rule does not prevent state and local governments from 
enforcing standards for installations after the initial installation or 
from imposing higher installation standards than are required by HUD's 
``minimum'' Model Installation Standards for the initial or any 
subsequent installation of a manufactured home. State standards for 
initial installation must meet or exceed HUD's minimum installation 
standards, while state standards for secondary installations do not 
have to adhere to the minimum HUD standards. HUD continues to believe 
that any subsequent installation of a manufactured home best resides 
with state authority. Notwithstanding all of the above, HUD will 
continue to study this issue in developing the final rule for its 
installation program regulations.
    Comment: Sec.  3285.1(c) Consultation With the Manufactured Housing 
Consensus Committee. The Manufactured Housing Consensus Committee 
(MHCC) should have a continuing involvement in revising the 
installation standards.
    HUD Response: HUD agrees with comments received from the MHCC and 
others that the Committee should have a continuing role in reviewing 
and recommending future changes to the Model Installation Standards. 
HUD recognizes the valuable guidance and assistance provided by the 
MHCC throughout the rulemaking process with the development of these 
installation standards. Accordingly, a new section, Sec.  3285.1(c), 
``Consultation with the Manufactured Housing Consensus Committee,'' has 
been included in the

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final rule. That section provides that HUD will afford the MHCC with a 
120-day opportunity to offer input and comment prior to proposing any 
changes to the installation standards. The new provisions also direct 
the MHCC to send its own suggested changes to the Department at least 
every 2 years. The final rule also provides that HUD will accept, 
modify, or reject each recommendation and explain to the MHCC the 
reasons behind any modifications or rejections of those recommendations 
before publication of any new revised standard.
    Comment: 3285.1(d) Administration. One commenter wrote that certain 
permanent site-built foundations with manufacturer certification are 
not subject to the proposed rule. This recognizes that site-built 
foundations under state and local codes are suitable and that all 
localities have such codes. It also implies that state and local codes 
for non-permanent foundations are lacking and that HUD needs to 
intervene. This does not make sense, unless there is a significant 
difference between permanent and non-permanent foundation requirements 
and their administration and enforcement.
    HUD Response: This provision stems from Section 604(f) of the Act 
and 24 CFR part 3282.12 of the Manufactured Home Procedural and 
Enforcement Regulations, which require HUD to exclude from coverage any 
structure which, among other things, is designed to be erected and 
installed upon a site-built permanent foundation.
    Comment: Sec. Sec.  3285.2, 3285.301(b), 3285.401 HUD Question: 
Should the Model Installation Standards offer more performance-based 
equivalents instead of prescriptive requirements to facilitate the use 
of alternative installation methods?
    HUD Response: Based on the recommendations of the MHCC and the 
public comments, the final model installation standards are a 
combination of prescriptive and performance standards. While the 
minimum standards do offer prescriptive methods for compliance, they 
also provide for alternatives in design that will allow for innovation. 
Accordingly, manufacturers' instructions may be based on either the 
minimum requirements in these model installation standards or may use 
performance-based design in demonstrating compliance with these 
standards.
    Comment: Sec.  3285.2 Manufactured Installation Instructions/HUD 
Question. Should model-specific plans for installation be required and, 
if so, what minimum information should be required on the plans (i.e., 
pier capacities, minimum support and anchorage locations, other 
structural design requirements, plan-specific information for 
completion of utility systems, etc.)?
    Comment: This should be left up to each manufacturer to decide.
    Comment: There is no need to require model-specific home plan 
criteria for every conceivable single or multi-section home design as 
there must be some reliance on the manufacturer's installation manual 
for model-specific home designs as the model standard is the minimum 
necessary requirements.
    Comment: There is no need to require model-specific plan criteria 
for every conceivable floor plan and design under the Model 
Installation Standards. If there needs to be specialized criteria, the 
manufacturer can provide it in the installation manual that comes with 
the new home. The DAPIA will determine whether the specialized 
manufacturer's manual has met or exceeds the Model Installation 
Standards. With regard to Sec.  3285.403, the best alternative might be 
to permit the mating line anchorage/connection to be determined by the 
manufacturer's installation manual.
    HUD Response: HUD has decided that model-specific foundation plans 
are not required, but that special foundation and anchorage plans are 
required to address site-specific conditions or when the support and 
anchorage methods in the manufacturer's installation instructions are 
not suitable and vary from those included with the manufacturer's 
installation instructions.
    Comment: Sec.  3285.2 Manufactured Installation Instructions/HUD 
Question. Should the manufacturer's installation instructions provide 
that a professional engineer or registered architect must be consulted 
when general site conditions are not covered by the installation 
instructions?
    Comment: When instructions do not address specific site conditions 
and hazards, the foundations and anchorage should be designed by a 
professional engineer or registered architect.
    Comment: There is no reason for the Model Installation Standards to 
require that a professional engineer or architect be consulted for site 
preparation, if the manufacturer's manual does not cover this 
installation consideration. Such a requirement could substantially 
raise the cost of site preparation for the retailer/installer.
    Comment: It is not reasonable to expect the manufacturer to 
effectively give installation instructions and assume liability when 
they have no site-specific knowledge. ``A registered engineer is the 
right call.''
    Comment: The only way to get efficient and consistent installation 
compliance with both the Model Installation Standards and the 
manufacturer's support requirements is to require manufacturers to take 
responsibility for the vertical support of their own designs and to 
provide foundation plans with all pier locations and minimum pad sizes 
specified and drawn to scale, in a graphical format serviceable for 
both the permit process and the foundation layout at the jobsite.
    Comment: All engineered foundations should be designed per SEI/ASCE 
7, Loads for Buildings and Other Structures. This will allow engineers 
and architects to develop foundation designs that are capable of 
resisting all natural hazards at the site.
    Comment: Experience has shown that out-of-state registered 
professional engineers and architects unfamiliar with the conditions of 
the locality design foundation systems that fail, and that the engineer 
or architect should be registered in the state where the home is to be 
installed.
    HUD Response: Section 3285.2(c) of the final rule has been revised 
specifically to allow for variations to be made to installation 
instructions for site conditions that are not covered, provided that 
installers first attempt to obtain those variations for site-specific 
conditions from the manufacturer and, if not available from the 
manufacturer, the installer is to use designs prepared by a 
professional engineer or registered architect. The installer must have 
the professional engineer's or registered architect's design approved 
by the manufacturer and its DAPIA prior to installation. DAPIA approval 
is necessary to enable HUD to enforce such modifications to the 
manufacturer's installation instructions. HUD has determined that the 
Model Installation Standards do not need to require that professional 
engineers or registered architects be licensed in the state where the 
home is to be installed, since they are responsible for only performing 
work or preparing designs in areas of construction in which they are 
competent and knowledgeable. However, a state that operates its own 
installation program may require that the engineer or architect be 
specifically licensed by that state.
    Comment: HUD requested comments on the efforts associated with 
checking installation instructions. One commenter wrote that since 
installation instructions vary by manufacturer and model, the estimates 
of number of respondents and responses per respondent were very low, 
while the number of hours spent on review was

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high, unless the time includes back-and-forth communication. If HUD 
does not intend to take action to ensure conformity with the Model 
Installation Standards (MIS), there is no need to collect this data.
    HUD Response: This issue will be addressed under the installation 
program regulations and any adjustments to the burden estimates will be 
made as part of those regulations.
    Comment: Section 3285.4 Incorporation by Reference. There is a more 
recent edition of the American Society of Heating, Refrigerating and 
Air-Conditioning Engineers Fundamentals Handbook and the Underwriters' 
Laboratories (UL) 181 standard has been separated into UL 181, 181A, 
and 181B.
    Comment: Add the American Wood Preservers Association (AWPA) to the 
list of Referenced Publications. AWPA Publications, American Wood-
Preservers' Association, P.O. Box 388, Selma, AL 36702. AWPA U1-04, Use 
Category System: User Specification for Treated Wood, 2004, and AWPA 
M4-02, Standard for the Care of Preservative-Treated Wood Products, 
2002. The references to treated wood standards need to be updated 
because: (1) AWPA C2 and C9 are no longer updated by AWPA and will not 
include new preservative treatments that are appropriate for this 
application; (2) Standard U1 is currently referenced in the 2004 
amendments to the 2003 International Building Code (IBC) and 
International Residential Code (IRC) in place of standards C2 and C9 
and will be referenced in the 2006 editions; and (3) the 0.60 lbs. per 
cubic foot is not the required retention level for all of the 
appropriate preservatives. Copper azole (CA-B) has a required retention 
of 0.31 lbs. per cubic foot for this application that is equivalent to 
Chromated Copper Arsenate used at 0.60 lbs. per cubic foot.
    HUD Response: The editions of these standards that are adopted in 
this final rule are consistent with those recently updated by HUD in 
recent amendments to the Manufactured Home Construction and Safety 
Standards. HUD will consider issuing conforming amendments to more 
recent editions of these standards in future rulemaking.
    HUD also agrees there is a need to update and revise the reference 
requirements for treated wood materials, and the final rule 
incorporates the more recent AWPA U1-04 and AWPA M4-02 standards into 
certain sections of the installation standards (Sec. Sec.  3285.4, 
3285.303, 3285.312, and 3285.504).
    Comment: Sec.  3285.5 Definitions. ``Design Flood.'' The term 
``design flood'' is used several times in the proposed rule and should 
be defined as the greater of either: (1) The base flood or (2) the 
flood so designated by the Local Authority Having Jurisdiction (LAHJ) 
as its regulatory flood, with a one percent chance or less of being 
equaled or exceeded in any given year.
    Comment: The term ``design flood elevation'' (DFE) should be added 
to the definitions as follows: ``Design Flood Elevation. The elevation 
of the design flood, including wave height, relative to the datum 
specified on a LAHJ's hazard map.''
    Comment: Sec.  3285.5 Definitions. ``Lowest-Floor.'' The definition 
of Lowest Floor should be revised, as follows: ``Lowest floor. The 
floor of the lowest enclosed area of a manufactured home. For flood-
resistant design purposes of these MIS, the term ``lowest floor'' shall 
mean the bottom of the longitudinal chassis frame beam in A zones, and 
the bottom of the lowest horizontal structural member supporting the 
home in V zones. An unfinished or flood resistant enclosure, used 
solely for vehicle parking, home access, or limited storage, must not 
be considered the lowest floor, provided the enclosed area is not 
constructed so as to render the home in violation of the flood related 
provisions of this standard.''
    HUD Response: Section 3285.102 of the final rule clarifies that the 
above terms are used as defined in 44 CFR part 59.1 of the National 
Flood Insurance Program and, as such, are not required to be again 
defined in these installation standards.
    Comment: Sec.  3285.5 Definitions. ``Labeled'' and ``Listed or 
certified.'' The term ``labeled'' is very similar to the term ``listed 
or certified,'' except that ``listed or certified'' requires that an 
approved product be on a published list. All of these terms could be 
read to require the contracting of an agency on a continuing basis to 
maintain product approval status rather than using a nationally 
recognized third-party testing agency for a one-time approval.
    HUD Response: Both terms remain in the final rule because certain 
components may not be required to be labeled but must still be listed 
under the purview of a nationally recognized testing laboratory.
    Comment: Sec.  3285.5 Definitions. ``Crossovers.'' The definition 
of crossovers should be amended to include ducting for both heating and 
cooling ducting, and not just ducting for heating.
    HUD Response: As recommended by the commenters, the final rule 
includes both heating and cooling ducts in the definition of 
``crossovers.''
    Comment: Sec.  3285.5 Definitions. ``Local Authority Having 
Jurisdiction (LAHJ).'' The definition of LAHJ should be rewritten to 
refer to local responsibilities in such a way that if they are within 
the coverage of the Model Installation Standards (MIS) they are 
applicable, but if outside the MIS they are not applicable.
    Comment: Having states included within the definition of an LAHJ 
seems to conflict with other provisions of the rule and means that a 
state or local government entity that does not have such requirements, 
even though they may be identical to the MIS, would not be considered 
an LAHJ. One commenter wrote that no level of government below the 
state level should be included in the definition of an LAHJ, because it 
implies that lower levels of government's programs are sanctioned, 
which could result in the imposition of additional fees, thereby 
causing increased costs for consumers.
    HUD Response: The definition is essentially unchanged in the final 
rule because any entity or subdivision of state government is not 
restricted from establishing more stringent requirements than those in 
the MIS for states in which HUD will operate the installation program. 
The proposed rule for the installation program regulations in 24 CFR 
part 3286 includes detailed provisions for state-run installation 
programs and how those requirements will impact on local governmental 
entities within their state. However, the definition has been modified 
in the final rule to clarify that an LAHJ must have both 
responsibilities and requirements that must be complied with during the 
installation of a manufactured home.
    Comment: Sec.  3285.5 Definitions. ``State.'' The ``Canal Zone'' 
should be deleted from the definition of ``State,'' because the Panama 
Canal Zone has not been under United States control or jurisdiction for 
nearly 30 years. emsp;
    HUD Response: HUD has removed ``the Canal Zone'' from the 
definition of ``State,'' but recognizes that the statute has not been 
amended or updated to reflect this change.
    Comment: Sec.  3285.5 Definitions. ``Foundation.'' The term 
``foundation'' should be a defined term in the MIS.
    HUD Response: A definition for a ``foundation system'' has been 
included in the final rule in both the Manufactured Home Construction 
and Safety Standards and the MIS.

Subpart B--Pre-Installation Considerations

    Comment: Seismic Safety/HUD Question: Should the MIS attempt to set 
forth minimum installation

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requirements or pre-installation considerations to address seismic 
safety? If so, how should HUD establish seismic zones and what minimum 
requirements would be included in the Model Installation Standards?
    Comment: If seismic zones are to be considered in the future as a 
manufactured home design parameter, it is best that they first be 
introduced into part 3280 and then mentioned in set-up manuals.
    Comment: Part 3285 contains no criteria to protect homes from 
earthquakes, and this omission makes the standard incomplete. Other 
national consensus standards have seismic criteria, such as the IBC, 
the IRC, the National Fire Protection Association (NFPA) 5000 Building 
Construction and Safety Code, and the NFPA 225. Manufactured homes fall 
off this type of support at very moderate ground shaking levels, since 
such homes are typically installed using piers not designated for 
seismic resistance, which are not adequately attached and connected to 
the foundation and chassis of the home. This lack of seismic resistant 
provisions will result in significantly less protection than in other 
types of residential construction, and is technically inadequate in 
areas of high seismic activity. Congress authorized the Earthquake 
Hazard Reductions Program to develop seismic safety provisions suitable 
for use throughout the United States. The lack of seismic provisions is 
contrary to national policy. The approach for seismic detailing and 
design in NFPA 225 should be accepted and used in part 3285.
    Comment: HUD should not include any seismic requirements in the 
Model Installation Standards. When required, designs are handled by the 
retailer, the installer, the owner, or the manufacturer, in accordance 
with the requirements of the local building authority. This is working 
now and need not be covered in the installation standards.
    HUD Response: The final rule does not contain specific requirements 
for the design of foundation and anchorage systems in seismically 
active areas. This will allow states and local building code 
authorities in seismically active areas to establish or continue to 
enforce foundation and anchoring requirements for seismic design load 
considerations. However, HUD intends to continue to study this issue 
and may recommend requirements for seismic design in future rulemakings 
in the Manufactured Home Construction and Safety Standards and the 
Model Installation Standards.
    Comment: Sec.  3285.101 Installation of Manufactured Homes in Flood 
Hazard Areas. The requirements for installation of manufactured homes 
in flood hazard areas should be included in Subpart D Foundations, 
Sec.  3285.302, rather than in Sec.  3285.101(d). While Sec.  3285.101 
requires the installer to determine if flood hazards affect the site, 
it is more appropriate that more explicit design considerations be 
articulated in the section on foundations.
    Comment: States and communities in areas that are vulnerable to 
flood damage should adopt regulations that exceed the minimum National 
Flood Insurance Program (NFIP) requirements.
    Comment: The approach indicated in the proposed Model Installation 
Standards was considered and rejected by NFPA 225. Basic performance 
requirements related to floods can and must be included in the Model 
Installation Standards, and doing so will not conflict with, replace, 
or preempt NFIP and LAHJ flood requirements.
    Comment: Method and Practices. Manufactured homes located wholly or 
partly within special flood hazard areas must be installed using 
methods and practices that minimize flood damage during the base flood, 
including elevation and stability of the foundation for anticipated 
conditions and loads in accordance with the LAHJ; 44 CFR 60.3(a) 
through (e), as applicable; and other provisions of 44 CFR referenced 
by those paragraphs.
    Comment: Section 3285.101(c) should be revised to read as follows: 
``(c) Pre-installation considerations. Prior to the initial 
installation of a new manufactured home, the installer is responsible 
to determine whether the manufactured home site lies wholly or partly 
within a special flood hazard area as shown on the LAHJ's Flood 
Insurance Rate Map, Flood Boundary and Floodway Map, or Flood Hazard 
Boundary Map. If so located, the map and supporting studies and 
requirements adopted by the LAHJ or state should be used to determine 
the flood hazard zone and design flood elevation at the site. If the 
LAHJ has not adopted a Flood Hazard Map, the installer shall consult 
the LAHJ to determine flood-resistant installation requirements.''
    Comment: Sec.  3285.101(d) Installation of Manufactured Homes in 
Flood Hazard Areas. LAHJs should be given the option to enforce 
requirements for flood hazards at whatever level they deem necessary. 
The section should provide two options for flood hazard criteria: (1) 
Per the LAHJ or (2) per the NFIP regulations.
    Comment: Paragraph (d)(2) should be renumbered as (d)(3) and a new 
section (d)(2) should be added, as follows: ``Performance requirements. 
Manufactured home installations shall: (a) Have the lowest floor 
elevated to or above the design installation; (b) elevate the home 
using support and anchorage systems designed and constructed to resist 
design flood loads in combination with other storage loads; (c) 
construct the support and anchorage system with flood damage resistant 
materials; (d) in A zones, use flood openings in permanent foundation 
walls and in other solid walls (excluding skirting) forming an 
enclosure below the DFE, to allow the automatic equalization of flood 
levels; and (e) in V zones, elevate the home on piles, columns, piers, 
or stands that minimize obstructions below the DFE, and use breakaway 
construction for any other non-structural walls or elements.''
    Comment: Fill is often used as a method to elevate sites so that 
the lowest floors of manufactured homes are elevated to or above the 
design flood elevation. While compaction of fill used to elevate a 
manufactured home site is an important consideration, there are other 
particular considerations that are important so that flood conditions 
do not adversely affect the fill. In particular, it is recommended that 
the fill be sloped and protected with vegetation to minimize erosion 
that may undermine the home. This can be accomplished by adding Sec.  
3285.101(d)(2) to read as follows: ``Installation on fill. Fill placed 
in flood hazard areas in order to elevate manufactured home sites shall 
be placed, compacted, and sloped to minimize shifting, slumping, and 
erosion during the rise and fall of floodwater.''
    Comment: A new paragraph, Sec.  3285.101(e), should be added to 
read as follows: ``Alternate Flood-Resistant Installation Provisions. 
The flood-resistant installation provisions contained in NFPA 225 shall 
be deemed to equal or exceed the flood requirements of the Model 
Installation Standards.''
    Comment: The only way to prevent flood damage is by elevating the 
home above the flood level on strong and durable stabilizing devices. 
Performance requirements to prevent flood damage must be included if 
the Model Installation Standards are to be effective.
    HUD Response: The final rule continues to reference the provisions 
of 44 CFR 60.3(a) through (e) and Federal Emergency Management Agency 
(FEMA) 85, Manufactured Home

[[Page 59343]]

Installation in Flood Hazard Areas, as appropriate guidance for 
installation of manufactured homes in areas subject to flooding. A 
state or local community may adopt more stringent performance 
requirements than those specified under the Model Installation 
Standards for flood hazard areas.
    Comment: Sec.  3285.102 Design Zone Maps. The design and 
construction of the foundation and anchoring systems addressed in part 
3285 should be compatible with the design and construction of the home, 
but should not be restricted or limited by the outdated and obsolete 
design zone maps contained in part 3280.
    Comment: This section should require that a manufactured home 
cannot be installed in a higher wind zone, snow load, or thermal zone 
than the home's original design for its initial installation.
    Comment: The referenced design maps identified in part 3280 should 
be included in this section.
    HUD Response: Section 3285.103(a) of the final rule requires that 
prior to the initial installation of a new manufactured home, the 
installer verify that the design and construction of the home, as 
indicated on the design zone maps provided with the home required by 
the Manufactured Home Construction and Safety Standards and 
regulations, are suitable for the site location where the home is to be 
installed.

Subpart C--Site Preparation

    Sec.  3285.201 Soil Conditions/HUD Question. HUD sought comment on 
whether the standards should require that a minimum of six inches of 
soil, including the organic material, be removed under load bearing 
footings to ensure that footings are placed on undisturbed soil for at-
grade footings.
    Comment: This would seem like a good practice in general to avoid 
detrimental effects to foundation support and anchoring systems; 
however, to specify a minimum depth of six inches of soil be removed 
may in some cases be too little or in other situations too excessive. 
To address this concern, the commenters recommend that the section be 
revised to indicate that topsoil is to be removed or that at-grade 
footings should be installed on undisturbed soil.
    HUD Response: HUD finds the comment to be reasonable, and the final 
rule does not specify a required depth of soil removal, thereby leaving 
the determination of firm, undisturbed soil as a site-specific matter.
    Comment: Sec.  3285.202 Soil Classifications and Bearing Capacity. 
The pocket penetrometer should be included as an acceptable method to 
determine soil-bearing capacity. While penetrometers are not as precise 
a method for determining soil-bearing capacity at an individual 
location, they have proven to be workable devices where multiple 
readings are taken at an installation site.
    Comment: The proposed rule should offer a default approach to 
determine the soil bearing capacity such as permitted by other model 
codes. This default approach used in some state and model building 
codes, such as the 2003 International Residential Code, generally 
recognizes a minimum soil bearing capacity of 1500 pounds per square 
foot (psf).
    HUD Response: The final rule now allows the use of the pocket 
penetrometer as one of the acceptable methods for determining soil 
classification and bearing capacity and permits the use of a 1500 psf 
soil bearing capacity, unless site-specific information requires the 
use of lower values based on soil classification and type.
    Comment: Sec.  3285.203(a) Drainage. The section should be revised 
to read as follows: ``Drainage must be provided to direct surface water 
away from the home.'' This was suggested because the commenter believed 
it unnecessary to include a ``laundry list'' of possible problems, if 
proper drainage was not provided, that was identified in the proposed 
rule.
    Comment: As written, subsection (b) would be impossible to enforce 
within rental communities given their layout and design. The 
requirement should be revised to provide an exemption for homes sited 
within manufactured home rental communities, or by changing the 
drainage requirement ``from under'' to ``away from'' the home. Further, 
in subsection (c) the first 10-foot provision would be impossible to 
enforce in rental communities, since lots only provide for 5-foot 
sideyards and that the requirement should be revised to require 
drainage away from the foundation of the home for the first 5 feet.
    HUD Response: The final rule has been revised to clarify that 
surface water must be directed away from the home to prevent water 
build-up under the home. Where property lines do not allow the drainage 
to be diverted for the first 10 feet from the foundation, other methods 
are allowed to remove the surface water. However, statements on the 
adverse affects of not removing the water have been removed from this 
section, as suggested by commenters.
    Comment: Sec.  3285.203(f) Gutters and Downspouts. Most home 
manufacturers do not provide additional support in the roof system in 
order to support gutters and downspouts. Installation could cause 
damage and take the home out of compliance with the MHCSS. However, if 
gutters and downspouts are provided, the runoff must be directed away 
from the manufactured home.
    Comment: Even though the Model Installation Standards require any 
runoff from gutters and downspouts to be diverted away from the home, 
not all HUD Code homes are required to have gutters and downspouts. If 
gutters and downspouts are provided, then installers should be required 
to ensure that adequate drainage is provided.
    HUD Response: The final rule has been revised to require 
manufacturers to specify in their installation instructions whether the 
manufactured home is suitable for the installation of gutters and 
downspouts and if so provided, the instructions are also to indicate 
that all roof water is to be directed away from the home.
    Sec.  3280.204 Ground Moisture Control/HUD Question: HUD is 
concerned that excessive voids and numerous tears in the vapor retarder 
can defeat the purpose of the requirement. Therefore, should 
limitations be placed on the number and size of voids and tears? If so, 
what specific limitations would be recommended?
    Comment: Some commenters advocated that the Model Installation 
Standards should state that all tears and voids in the ground vapor 
retarder be repaired. Others raised questions as to what would 
constitute a minor tear or void, as indicated in the proposed rule; how 
many tears or voids would be acceptable without repair; and how the 
regulation would be consistently enforced by states. The commenters 
also suggested this was one situation where a prescriptive provision is 
warranted in the standards.
    Comment: As it would be difficult to repair tears or defects in the 
ground vapor retarder around piers, the requirement should be revised 
to not require minor tears and voids at pier locations or other support 
to be repaired.
    Comment: The ground vapor retarder should be overlapped at least 12 
inches at all joints to prevent weeds and grass from growing through 
deck slats, and to minimize the likelihood of moisture penetration.
    Comment: The reference to a six millimeter polyethylene is a 
typographical error in Sec.  3285.204(b). A six millimeter polyethylene 
ground vapor retarder would be .039'' thick, as opposed to the six mil 
polyethylene that

[[Page 59344]]

was intended, which would be .006'' thick.
    Comment: Ground vapor retarders should be required only in enclosed 
areas and paragraph (a) should be revised to read as follows: ``(a) If 
space under the home is to be enclosed with skirting or other material, 
a vapor retarder is required in the following situations: (1) In humid 
regions (this region is considered to follow the very heavy termite 
infestation probability map, reference in the HUD Sept., 1996 PFGMH); 
(2) in situations where the crawlspace soil elevation is below the 
natural surrounding surface elevation (i.e., pit set applications); (3) 
in installations where concrete decks, retaining walls or other solid 
barriers prevent venting on more than one side (refer to Sec.  
3285.505).''
    HUD Response: Section 3285.204 of the final rule does not permit 
any voids or tears in the ground vapor retarder, requires all joints to 
be overlapped at least 12 inches, and allows the vapor retarder to be 
installed around or over footings and other obstructions, as suggested 
by the commenters. The final rule also corrects the typographical error 
in the proposed rule in paragraph (b) by requiring the thickness of the 
vapor retarder to be a minimum of six mil polyethylene sheeting. The 
final rule also clarifies that all enclosed and skirted areas are to be 
provided with a ground vapor retarder, except in arid regions and areas 
for open porches, decks, and recessed entries.

Subpart D--Foundations

    Comment: Sec.  3285.301(b) Alternative Foundation Systems. The 
requirement that foundations that are not of the pier and footing type 
are to be designed by a professional engineer increases costs to the 
consumer.
    Comment: It is unnecessary for a professional engineer or architect 
to be consulted for site preparation, if the manufacturer's manual does 
not cover the specific conditions for the site, because every manual 
has been reviewed by the industry's national association and it always 
contains some information with regard to site preparation. If not, the 
LAHJ can be looked to for any other conforming requirements.
    Comment: Sec.  3285.301(b) et al. The proposed rule's requirements 
for ``acceptable engineering practice'' are too broad to ensure 
uniformity. As written, the commenter finds four problems with the 
proposed language: (1) It suggests that all aspects of design require 
registered professionals, (2) the standard is not specific to the 
design and construction of manufactured homes, (3) it is not specified 
where the professional has to be registered, and (4) it will increase 
costs because services of engineers and architects will be required for 
each installation rather than having the manufacturer provide the 
information universally. The commenter proposes to change the language 
to read, * * * Must be prepared by the manufacturer or by a registered 
professional engineer or a registered architect in accordance with the 
manufacturer's home design and the Manufactured Home Construction and 
Safety Standards (3280).'' [Same comment for Sec. Sec.  3285.301(d), 
3285.306(c), 3285.310(c), 3285.312(c)(1) and (2), 3285.314(b), 
3285.401(b) and (b)(2), 3285.402(c)]
    Comment: Sec.  3285.301(c) General. Most registered professional 
engineers or registered architects are not aware of the federal 
standards or how manufactured homes are designed and constructed. They 
are also unaware of critical areas of support. If the designs fail, the 
federal program has no authority over these outside professionals.
    HUD Response: The requirements for the use of professional 
engineers or architects to certify various aspects of the 
manufacturer's installation instructions for foundation and anchoring 
support, including alternative foundation systems, are retained in the 
final rule and are no different than what is currently required for 
certification of this information under the Manufactured Home 
Construction and Safety Standards. In addition, one of the 
responsibilities of a professional engineer or registered architect is 
to understand all aspects of any design, including critical areas of 
support, before certifying that it complies with the appropriate 
standards or requirements. The installer must have the professional 
engineer's or registered architect's design approved by the 
manufacturer and its DAPIA prior to installation. DAPIA approval is 
necessary to enable HUD to enforce such modifications to the 
manufacturer's installation instructions.
    Comment: Installation Instructions for Perimeter and Permanent 
Foundations/HUD Question: Should manufacturers who design their 
manufactured homes to be installed on perimeter or permanent 
foundations, in addition to pier, footing, and anchor foundations, be 
required to also provide DAPIA-approved installation instructions for 
perimeter and/or permanent foundations and the pier, footing, and 
anchor systems?
    Comment: Additional DAPIA-approved instructions for other 
foundation systems, including perimeter or permanent foundations, 
should not be required if a manufacturer has complied with either 
engineered plans or state-established standards for permanent 
foundations.
    HUD Response: DAPIA-approved installation instructions are required 
to be provided by manufacturers under section 605(b) of the Act. The 
final rule indicates that foundation systems that are not of pier and 
anchor type configurations may also be used, when substantiated by 
engineering design as being capable of resisting the design loads in 
the Manufactured Home Construction and Safety Standards. If alternative 
foundation designs are not provided in the installation instructions 
and are desired or needed for site-specific conditions, installers are 
required to first contact manufacturers to obtain variations to the 
instructions or, if not available from the manufacturer, to use a 
design prepared by a professional engineer or architect (Sec.  
3285.2(c)). The installer must have the professional engineer's or 
registered architect's design approved by the manufacturer and its 
DAPIA prior to installation. DAPIA approval is necessary to enable HUD 
to enforce such modifications to the manufacturer's installation 
instructions.
    Comment: Sec.  3285.301(a) General. The design of the foundation 
system should not be limited to the design loads required by the 
Manufactured Home Construction and Safety Standards, as indicated on 
the home's data plate. Presently, manufactured homes are not designed 
for flood loads, but foundation and anchorage systems sited in flood 
hazard areas should be capable of resisting flood loads. Similarly, 
manufactured homes are not presently designed for seismic forces, but 
foundation and anchorage systems installed in areas subject to 
earthquake forces should be capable of resisting seismic loads. To 
remedy the above concerns, the section should be revised to read as 
follows: ``(a) Foundations for manufactured home installations must be 
designed and constructed in accordance with this subpart and must be 
based on site conditions, home design features, and the greater of (1) 
the loads the home was designed to withstand as shown on the home's 
data plate, and (2) design loads specified elsewhere in these Standards 
or by the LAHJ or state.''
    HUD Response: Under the final rule, states and localities are not 
prevented from establishing and enforcing seismic requirements or 
higher design requirements for foundations and anchorage to resist 
flood loads.

[[Page 59345]]

    Comment: Test Protocol for Alternative Foundation Systems/HUD 
Question: What specific requirements should be included in the national 
test protocol for alternative foundation systems protocol referred to 
in the proposed Model Installation Standards?
    Comment: It would be best to delay providing any specific 
considerations or testing requirements in the final rule, because the 
MHCC has been tasked to develop a recommended test protocol for 
proprietary foundation systems. Further, any proprietary system can be 
evaluated by a manufacturer and included, at its option, in the 
installation manual, subject to DAPIA approval.
    Comment: Currently a de facto, nationally recognized protocol 
exists, which has been extensively used to evaluate most of the 
alternative foundation systems on the market.
    HUD Response: Section 3285.301(d) of the final rule includes 
provisions for a nationally recognized testing protocol for proprietary 
foundation systems or alternatively requires proprietary foundation 
system designs to be prepared or tested by a registered professional 
engineer or registered architect. Efforts are underway by the MHCC to 
develop recommendations for a national testing protocol, which will be 
considered by the Department of Housing and Urban Development upon its 
completion. Presently, states that are operating an installation 
program have differing requirements for the testing of proprietary 
foundation systems, and there is no universally accepted de facto 
method for testing, as suggested by one of the commenters.
    Comment: Sec.  3285.302 Installation of Manufactured Homes in Flood 
Hazard Areas. Manufacturers should be required to either include flood-
resistant considerations in their foundation specifications (and state 
the conditions under which the specifications are applicable in terms 
of specific ranges of velocities, depths, and wave action), or state 
that their foundation specifications do not address flood loads and 
shall not be used in flood hazard areas.
    HUD Response: Section 3285.302 of the final rule requires that the 
installation instructions identify whether the foundation 
specifications have been designed or not designed for flood-resistant 
considerations.
    Comment: Sec.  3285.303(b)(1) Acceptable Piers-Material 
Specifications. The section should be revised to read as follows: 
``Piers are permitted to be concrete blocks, pressure-treated wood 
treated with a water-borne preservative in accordance with AWPA 
Standard U1 for Use Category 4B ground contact applications, or 
adjustable metal or concrete piers.''
    HUD Response: Section 3285.301(b) of the final rule has been 
revised in accordance with the above comment to reference a more 
current standard permitting the use of water-borne preservatives for 
pressure treatment of wood members.
    Comment: Sec.  3285.303 Piers/HUD Question: Should the Model 
Installation Standards include other design characteristics or 
standards for manufactured piers such as protection from the elements, 
material specifications, a testing protocol, or listing and labeling 
requirements?
    Comment: Piers and other support or anchorage devices should be 
designed and constructed to resist weathering, corrosion, and 
deterioration with minimal maintenance and upkeep on the part of the 
owner. This is especially important in coastal areas where salt spray 
corrosion is present, and in flood hazard areas where the supports and 
anchorage are subject to inundation.
    Comment: Manufactured piers are designed to withstand certain loads 
and, as long as the home manufacturer provides the loading requirements 
at each intended pier location, a manufactured pier that is capable of 
resisting those loads should be acceptable for use.
    Comment: The proposed rule specifies that manufactured home piers, 
other than concrete masonry units or steel jack stands, be listed and 
labeled for the required vertical loads and appropriate lateral loads. 
This appears to be a performance-based requirement. There does not seem 
to be any reason to provide a laundry list of design conditions. HUD 
should maintain the status quo until some nationally recognized 
material/testing protocol can be developed.
    HUD Response: The proposed rule did not exclude metal stands or 
piers from the requirement to be listed and labeled, as suggested by 
the commenter. This is further clarified in Sec.  3285.308 of the final 
rule, which requires that any metal pier or other type of manufactured 
pier be listed, meet the pier load requirements of the Model 
Installation Standards in Sec.  3285.303, and be protected against 
weather deterioration and corrosion.
    Comment: Sec.  3285.303(d) Pier Loads. The word ``poured'' should 
be deleted, as it suggests that the footers for piers loads need to be 
poured.
    HUD Response: The term ``poured'' has been deleted in the final 
rule.
    Comment: Sec.  3285.303 Tables 1, 2, and 3. The Tables are 
confusing and should be simplified by retaining only the ``Pier and 
Footing Load'' column and by deleting all references to the 16''x16'' 
concrete footing /pyramid layout method in the Tables and by deleting 
Figure C to Sec.  3285.312 in its entirety.
    Comment: The footnotes in the tables should indicate that flood or 
seismic loads were not considered in developing the tables and that the 
tables should not be used in determining foundation requirements in 
flood hazard areas or seismic hazard areas.
    HUD Response: The Tables in the final rule have been revised to 
delete the references to footing layouts, and Figure C to Sec.  
3285.312 has also been deleted in the final rule. A footnote has also 
been added to each of the Tables in the final rule indicating the 
Tables do not consider flood hazard or seismic design load 
requirements.
    Comment: Sec.  3285.304 Pier Configuration. There are a number of 
inconsistencies between the text in this section and Figures A and B to 
Sec.  3285.306 with regard to cap thickness, size, and material 
callouts and specifications; shim size, use, thickness, and 
orientation; and gaps between the main chassis beam and foundation 
support system specifics.
    HUD Response: Figures A and B and the text of this section have 
been revised in the final rule to address comments regarding 
inconsistencies between them in cap requirements (i.e., \1/
2\-steel plate thickness has been used in both the text and 
Figures in the final rule), by requiring wood shims to be hardwood and 
by clarifying alternatives for filling gaps.
    Comment: Sec.  3285.305 Clearance Under Homes/HUD Question: Should 
the Model Installation Standards include minimum clearances in areas 
such as those required for access or inspection?
    Comment: A minimum clearance under a home is required to install 
and inspect utility connections, bottom board repairs, etc. All of the 
area underneath a home should be accessible for that, and even if there 
are no utility connections in an area, bottom board repairs may still 
need to be made on-site.
    Comment: A 12-inch minimum clearance should be maintained beneath 
the lowest member of the main frame and the ground under 100 percent of 
the home.
    HUD Response: The final rule requires a minimum clearance of 12 
inches under the home to the ground, including areas between the lowest 
point of the frame and the grade.

[[Page 59346]]

    Comment: Sec.  3285.306(b) Frame Piers 36 Inches to 80 Inches and 
Corner Piers. The MHCC and other commenters stated that mortar should 
not be required, unless specified in the manufacturer's installation 
instructions. Further, if mortar is required for all frame or corner 
piers between 36 inches and 67 inches in height, it would add 
unnecessary costs to the installation of the home.
    Comment: When concrete block piers are required to use mortar, the 
type of mortar should be indicated in the standards.
    Comment: Section 3285.306(a)(5) should be changed to read as 
follows: ``Mortar is not required if a solid 4 cap block is 
placed on top of the hollow masonry blocks and the pier is not being 
considered as an anchoring point, unless otherwise specified in the 
installation instruction or required by a registered engineer or 
registered architect.''
    HUD Response: Paragraphs (a), (b), and (c) of Sec.  3285.306 of the 
final rule have been revised to indicate that the use of mortar is only 
required when specified in the manufacturers installation instructions 
or required in designs prepared by a professional engineer or 
registered architect.
    Comment: Sec.  3285.306(b)(2). The Model Installation Standards 
should address offsets in piers over 36 in height and the 
maximum tilt of piers from vertical for piers of any height.
    HUD Response: Horizontal offsets for piers over 36 and 
up to 67 in height are limited to 1 in Sec.  
3285.306(b)(1) of the final rule.
    Comment: Figure B to Sec.  3285.306 Typical Footing and Pier 
Installation, Double Concrete Block. The maximum pier height of 80 
inches should be reduced to 67 inches, because the tie-down charts 
provided in this standard are limited to 67'' and pier designs greater 
than 67'' in height will require independent engineering designs.
    HUD Response: The requirements for frame and corner pier height in 
Figure B and the text of the final rule have been reduced from 80 
inches to 67 inches to be consistent with other tables and figures in 
the Model Installation Standards.
    Comment: Sec.  3285.309 Elevated Homes. Since information is 
provided for designing tie-downs and piers up to 67'' high, the ``one-
fourth of the area of a home'' requirement should be deleted.
    HUD Response: The provisions for elevated homes have been deleted 
in the final rule, as recommended by the commenters. A professional 
engineer or registered architect would be required to prepare designs 
that exceed 67'' in height or for other conditions not specifically 
addressed by these Model Installation Standards.
    Comment: Sec.  3285.310 Figures/Tables for Marriage Line Pier 
Supports (Generally). The manufacturer's installation manual would be 
easier to reference for these requirements rather than the 
specifications, Tables, and Figures in the proposed rule.
    HUD Response: As recommended by the MHCC and others, the Tables, 
Figures, and specifications are needed to establish the minimum 
requirements and guidance needed for preparing manufacturer's 
installation instructions.
    Comment: Sec.  3285.310 Typical Mate-Line Column Pier and Mating 
Wall Support. Footnote 1 of Figure A to Sec.  3285.310 requires all 
footings to extend below the frost line depth. This requirement is 
inconsistent with Sec.  3285.312(c), which allows footings to be 
located at grade, when insulated foundation systems are used in areas 
subject to freezing. Instead, Footnote 1 should be revised to reference 
Sec.  3285.312(c) for footing requirements in frost-heave susceptible 
soils. This same comment also applies to Figure B.
    Comment: Figure A to Sec.  3285.310 Typical Mate-Line Column Pier 
and Mating Wall Support When Frame-Only Blocking is Required and Figure 
B to Sec.  3285.310 Typical Mate-Line Column Pier and Mating Wall 
Support When Perimeter Blocking is Required. For locations more than 
two feet from the perimeter of the home, the frost line depth should be 
one half of that required for perimeter footings, because temperatures 
under the home are not low enough to cause severe soil frost line 
conditions.
    Comment: The pier capacity indicated in Footnote 3 for single dry 
stack concrete block piers should be reduced from 10,000 lbs. to 8,000 
lbs., while another commenter recommended the capacity be reduced even 
further to 5,725 lbs.
    Comment: Footnote 6 for Figure A and Footnote 4 for Figure B should 
be revised to indicate that pier or other supports are required for any 
opening 48'' or greater at either the mate-line or the side wall.
    HUD Response: Footnote 1 of the Figures A and B to Sec.  3285.310 
in the final rule have been revised to indicate that the bottom of the 
footings must extend below the frost line depth, unless designed for 
placement above the frost line. In addition, alternatives to locating 
footings below the frost line, such as by using an insulated foundation 
system, are provided in Sec.  3285.312(b) of the