Manufactured Home Construction and Safety Standards, 72024-72052 [05-23387]

Agencies

• DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT

[Federal Register Volume 70, Number 229 (Wednesday, November 30, 2005)]
[Rules and Regulations]
[Pages 72024-72052]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-23387]



[[Page 72023]]

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Part IV





Department of Housing and Urban Development





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24 CFR Part 3280



Manufactured Home Construction and Safety Standards; Final Rule

Federal Register / Vol. 70, No. 229 / Wednesday, November 30, 2005 / 
Rules and Regulations

[[Page 72024]]


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DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT

24 CFR Part 3280

[Docket No. FR-4886-F-02]
RIN 2502-AI12


Manufactured Home Construction and Safety Standards

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

ACTION: Final rule.

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SUMMARY: This rule amends the Federal Manufactured Home Construction 
and Safety Standards (the Construction and Safety Standards) by 
adopting certain recommendations made to HUD by the Manufactured 
Housing Consensus Committee (MHCC). As required by the National 
Manufactured Housing Construction and Safety Standards Act of 1974 (the 
Act), HUD published, in the Federal Register on December 1, 2004, the 
first group of recommendations submitted by MHCC to improve various 
aspects of the Construction and Safety Standards. HUD, in publishing 
MHCC's recommendations in the proposed rule, indicated its agreement 
with all but a few of MHCC's proposals, and most of the recommendations 
are included in the final rule. HUD has also identified in this final 
rule those MHCC proposals that were not accepted by HUD, returned to 
MHCC for further consideration, or modified by HUD in light of public 
comments received.

DATES: Effective Date: May 30, 2006. The incorporation by reference of 
certain publications in this rule is approved by the Director of the 
Federal Register as of May 30, 2006.

FOR FURTHER INFORMATION CONTACT: William W. Matchneer III, Associate 
Deputy Assistant Secretary, Office of Regulatory Affairs and 
Manufactured Housing, Department of Housing and Urban Development, 451 
Seventh Street, SW., Room 9162, Washington DC 20410; telephone (202) 
708-6401 (this is not a toll-free number). Persons with hearing or 
speech impairments may access this number via TTY by calling the toll-
free Federal Information Relay Service at (800) 877-8389.

SUPPLEMENTARY INFORMATION:

I. Background

    On December 1, 2004, at 69 FR 70016, HUD published a proposed rule 
to amend various sections of the Federal Manufactured Home Construction 
and Safety Standards (24 CFR part 3280) by adopting a majority of the 
recommendations made to HUD by MHCC. The National Manufactured Housing 
Construction and Safety Standards Act of 1974, 42 U.S.C. 5401-5426 (the 
Act), requires HUD to publish any proposed revised Construction and 
Safety Standards submitted by MHCC in the Federal Register. The 
proposed rule contained the recommended revisions (including the 
recommendations made by MHCC that HUD modified, accepted, or did not 
accept) and provided an opportunity for public comment.
    HUD will continue to work with MHCC on its recommendation to remove 
the current requirement to post a Health Notice on formaldehyde 
emissions in each manufactured home. In addition, HUD is making the 
following significant changes to the proposed rule, based on the public 
comments, in this final rule:
    (1) The proposed revisions to improve the truss testing 
requirements in Sec.  3280.402 have been removed and are being returned 
to MHCC for further consideration on the recommendation of the 
commenters and at the request of MHCC.
    (2) Limited exceptions to the 5.0 perm requirements for interior 
wall surfaces of up to 50 square feet are permitted by the final rule 
for homes designed to be sited in hot-humid climates.
    (3) Updates to a number of the standards incorporated by reference 
that are more current than were suggested in the proposed rule are 
included in the final rule.

II. Analysis of Public Comments

The Commenters

    HUD received 26 public comments on the proposed rule. Comments were 
received from MHCC; manufactured home builders; a state's Department of 
Community and Economic Development; an independent inspection agency 
with experience in manufactured home design; a propane gas trade 
association; an energy efficiency alliance; a state and a national 
manufactured housing association; and associations representing 
particleboard, hardboard, and fiberboard manufacturers.

Summary of Public Comments

    The summary of public comments that follows presents the major 
issues and questions raised by the public commenters on the December 1, 
2004, proposed rule. The headings present the issue or question 
addressed, followed by a brief description of the commenters' 
reasoning. A response may be applicable to one or more issues or 
questions. The summary of the public comments is organized as follows:
    General comments.
    Whole-house ventilation comments.
    Fireblocking comments.
    Body and frame requirement comments.
    Formaldehyde health notice comments.
    Roof truss testing requirement comments.
    Thermal protection comments.
    Plumbing system comments.
    Heating, cooling, and fuel burning requirement comments.
    Electrical systems comments.
    Comments regarding revisions to standards incorporated by 
reference.
    Other public comments.
    Comments of the Manufactured Housing Consensus Committee.

General Comments

    Several commenters explained that they were encouraged that HUD and 
MHCC were working together to update the Construction and Safety 
Standards. Most commenters were very specific in commenting on 
particular amendments in the proposed rule.
    Commenters most often discussed the Department's decision not to 
delete the requirement for posting of a Health Notice on formaldehyde 
emissions in each manufactured home, the proposed amendments to the 
testing requirements for roof trusses, and the provisions for 
condensation control in hot-humid climates.
    Additional comments referred to whole-house ventilation systems, 
fireblocking requirements, vapor retarder installation requirements, 
flow faucet and showerhead restrictions, water heater drain pan 
requirements, revisions to the standards incorporated by reference, and 
metric equivalent requirements. Commenters also submitted comments on 
whether the approval of alternative test methods should be solely the 
responsibility of Design Approval Primary Inspection Agencies (DAPIAs), 
or whether DAPIAs should provisionally approve alternative test methods 
subject to HUD's approval.

Whole-House Ventilation Comments

    The December 1, 2004, proposed rule would have amended Sec.  
3280.103(b) by simplifying the requirements for sizing whole-house 
ventilation systems of manufactured homes.
    Comment: The current requirement for balanced mechanical 
ventilation systems should not be deleted. Two commenters wrote that 
permitting any pressure imbalance provides the opportunity for unwanted 
humid air infiltration and would be detrimental to homes sited in 
Thermal Zone I.

[[Page 72025]]

    HUD Response: The final rule does not eliminate the requirement for 
balanced mechanical systems. Retention of the requirement in the final 
rule better ensures that unwanted air infiltration is not introduced 
into the home. A HUD study entitled, ``Alternatives for Minimizing 
Moisture Problems in Hot, Humid Climates (2003)'' found that the most 
significant factors contributing to moisture problems were pressure 
imbalances in a house, including imbalances caused by uneven 
distribution of conditioned air; duct air leakage; and leakage through 
building walls.
    Comment: There is no requirement for additional fresh air to be 
introduced into the home for the whole-house ventilation system.
    HUD Response: There is sufficient leakage around the envelope of 
even a ``tight'' home to alleviate any pressure difference between the 
exterior and the interior of the home, and there is no need for an 
additional air inlet to be provided to moderate any imbalance in 
pressure resulting from operating a small exhaust fan device. 
Information provided to the Department by the Manufactured Home 
Research Alliance that was collected for the Energy Star Program also 
indicates there is sufficient leakage, even in tight homes, to handle 
any imbalance in pressure caused by the whole-house ventilation system.
    Comment: Locating the whole-house ventilation system in the 
bathroom is not a good idea. Two commenters wrote that consumers, 
attempting to lower their electric bills, will not operate bathroom 
fans as often as necessary and the effectiveness of the fans will thus 
be limited. One commenter wrote that the proposed change requires 
consumer education on the topic of the whole-house ventilation system.
    HUD Response: The alternative permitting the whole-house 
ventilation system to be installed in the bathroom is not included in 
the final rule. The Department agrees with the commenters that 
consumers may not utilize the bathroom fans often enough and has 
deleted this alternative for whole-house ventilation from the final 
rule.
    Comment: Whole-house ventilation is a good idea. One commenter 
wrote that the proposed rule would improve indoor air-quality, reduce 
energy consumption associated with mechanical ventilation systems, and 
provide crucial consumer education. Proper consumer use of quiet, 
reliable whole-house exhaust fans will reduce mold problems associated 
with internally generated moisture, and indoor air pollutant 
concentrations. The proposed whole-house ventilation strategy has been 
successfully employed in over 100,000 HUD-code homes built in the 
Pacific Northwest.
    HUD Response: The Department agrees that the concept of effective 
whole-house ventilation is an effective strategy to improve indoor air 
quality overall and that the revisions to the current requirements will 
further assist consumers in dealing with unwanted moisture and indoor 
air pollutants in their homes.

Fireblocking Comments

    The December 1, 2004, proposed rule would have amended Sec.  
3280.206 by clarifying existing language, locations, and acceptable 
materials that may be used where fireblocking is required. However, HUD 
had proposed modification of a portion of MHCC's proposal that would 
have permitted mineral wool or loose fill insulation to be considered 
acceptable fireblocking material.
    Comment: HUD should adopt MHCC's recommendations allowing the 
alternative fireblocking materials. One commenter wrote that HUD stated 
the removal of the recommended language allowing mineral wool and loose 
fill as acceptable fireblocking material was because these types of 
insulation have not been adequately evaluated for transportation 
effects that could cause settling or shifting when installed around 
pipes or vents in furnace and water heater compartments. The commenter 
wrote that the original MHCC recommendation addressed these concerns 
with alternative wording. The commenter recommended allowing the use of 
the fireblocking alternatives when the manufacturer can demonstrate the 
materials will remain in place. Another commenter wrote that HUD 
modified MHCC's recommendation by totally rejecting the inclusion of 
loose fill insulation as fireblocking material not only in roofs, but 
in walls and floors as well. The same commenter felt that MHCC's 
recommendations would address HUD's concerns about the material staying 
in place during transportation, etc., as long as the materials would 
have to pass tests that address HUD's concerns before they could be 
used. A third commenter wrote that HUD should reconsider its rejection 
of the use of mineral wool or loose fill insulation as an acceptable 
fireblocking material, because technical data shows that such material, 
when properly installed to a specified R value, is effective when used 
as fireblocking.
    Two commenters wrote that they supported fireblocking because it 
brings the Construction and Safety Standards into closer consistency 
with other building codes.
    HUD Response: The final rule includes all of the provisions for 
permitting fireblocking that were identified in the proposed rule and 
does not include requirements for loose fill insulation to be used as 
an alternative fireblocking material. However, in view of the comments 
received, the Department would reconsider its position to permit loose 
fill insulation to be used as fireblocking, if an acceptable testing 
procedure could be developed by MHCC or a voluntary consensus 
organization.

Body and Frame Requirement Comments

A. Body and Frame Requirements--Alternative Test Procedures
    The December 1, 2004, proposal would have amended Sec.  3280.303(g) 
by eliminating the requirement that a manufacturer submit alternative 
testing procedures to HUD, except for testing methods involving one-
piece metal roofing as would be required in Sec.  3280.305(c)(1)(iii). 
HUD sought comments specifically on whether the final approval of 
alternative test methods should be solely the responsibility of DAPIAs 
or whether DAPIAs should only be allowed to provisionally approve the 
test method subject to HUD's approval.
    Comment: DAPIAs should be allowed to approve alternate test 
methods. One commenter wrote that MHCC unanimously approved delegating 
approval to DAPIAs in its recommendation to HUD and still stands by 
that position. The commenter explained that HUD currently relies on 
DAPIAs to review and accept or reject all drawings, calculations, etc., 
supplied by the manufacturer for the home design. Another commenter 
stated that current regulations at Sec. Sec.  3282.203(b)(11) and 
3282.361(b)(2) require the homebuilder to submit reports for all tests 
and submit all design drawings and that Sec.  3282.203(c) provides the 
necessary regulations to carry out the quality assurance manual 
approvals, such as review and approval of the designs, testing, etc., 
used by manufacturers to build according to the Construction and Safety 
Standards. Commenters noted that they believe this authorization to be 
in line with current DAPIA authority and that HUD has sufficient 
remedies under the regulations to deal with a DAPIA's poor performance 
in any area of responsibility. Two commenters also wrote that it 
sometimes takes an extremely long period of time for HUD

[[Page 72026]]

to finally approve a suggested new method, thereby holding up the 
implementation of the material, component, or system being proposed by 
a manufacturer, and that DAPIAs are the most likely group to make 
informed decisions since they are familiar with the particular 
manufacturer and its design process. Another commenter wrote that 
``[i]n a word, the system was working fine before HUD added this pre-
approval criteria to 303(g) about 10 years ago and it will work fine 
once this item is eliminated.'' Another commenter explained that HUD 
should consider the changes in the law contained in the amendments made 
to the Act. Specifically, section 604(b)(3) of the Act calls for MHCC 
review of ``interpretative bulletins.'' Requiring HUD staff to pre-
approve these test procedures could be considered equivalent to the 
issuance of interpretative bulletins. Another commenter wrote that HUD 
has interpreted Sec.  3280.303(g) to mean that only manufacturers, not 
suppliers, can request such testing work be done. That has necessitated 
suppliers having to ``recruit'' cooperative manufacturers to 
``sponsor'' the test requests for the benefit of the industry. This has 
caused unnecessary delay that could be eliminated by DAPIAs simply 
working with the technical staff of a supplier to develop a 
``universally acceptable'' test protocol.
    One commenter wrote that HUD should review all alternative testing 
procedures prior to their implementation.
    HUD Response: The Department generally agrees with the commenters 
regarding the use of DAPIAs to approve other alternative test methods 
and procedures developed by manufacturers. As HUD has no regulatory 
authority over suppliers, the final rule continues to require 
manufacturers to develop the alternative testing procedures. 
Accordingly, the final rule allows DAPIAs to approve alternative 
testing procedures developed by manufacturers and for the procedures to 
thereby become part of the manufacturer's approved designs, except for 
testing procedures for one-piece metal roofing system designs. (See the 
discussion below under ``B. Body and Frame Requirements--Structural 
Design Requirements'' regarding testing procedures for one-piece metal 
roofing systems.)
B. Body and Frame Requirements--Structural Design Requirements
    1. The December 1, 2004, proposed rule would have amended Sec.  
3280.305(c)(1)(ii) by adding a footnote to permit the use of certain 
one-piece metal roofing without structural sheathing in the high Wind 
Zones II and III. HUD proposed to modify MHCC's recommendation for one-
piece metal roofing installed in high wind areas to be consistent with 
Interpretative Bulletin (IB) I-2-98 by requiring prior Departmental 
approval of any testing procedures used to demonstrate the 
acceptability of such systems.
    Comment: HUD should not have modified MHCC's recommendation for 
adding footnote 9 to the Table in Sec.  3280.305(c)(1)(ii) for one-
piece metal roofing and should not have required the testing procedures 
for these systems to be subject to HUD approval. Two commenters wrote 
that HUD has modified MHCC's proposal and in so doing would destroy the 
original intent of MHCC's recommendation. The commenters explained that 
HUD states it is modifying MHCC's proposal to make it more consistent 
with IB I-2-98, but the intent of MHCC's proposal was to eliminate the 
IB by rendering it null and void, not to conform to it. The commenters 
wrote that HUD had received 12 comments on the IB, all of which were 
negative; however, HUD ignored all comments and issued the IB as 
proposed. The commenters wrote that the addition of the language in the 
footnote is confusing, because all test methods are already required to 
comply with Sec.  3280.303(c) and (g) and Sec.  3280.401; thus, the 
addition of this language serves no purpose. HUD is trying to re-impose 
the same pre-approval of test methods that would be eliminated by Sec.  
3280.303(g) in the proposed rule. There is no valid reason for such 
pre-approval by HUD. The Department's proposal lacks justification as 
to why it believes pre-approval by its staff for this product/design is 
necessary when it is agreeing to eliminate pre-approval for all other 
current/future products and designs by changing Sec.  3280.303(g). The 
one-piece metal roof catenary design is much stronger than the 
prescriptive roof sheathing option currently permitted by footnote 7 to 
the Table for Resisting Uplift Loads.
    HUD Response: The final rule continues to require HUD approval of 
testing procedures for one-piece metal roofing due to the large number 
of failures of these systems that occurred in the 2004 hurricanes in 
Florida. However, the requirements will be contained in Sec.  
3280.305(c)(1)(iii) of the Construction and Safety Standards rather 
than in a footnote to the Table of Design Wind Pressures as indicated 
in the preamble of the proposed rule. Presently, there is no recognized 
or available testing procedure that will comprehensively and adequately 
evaluate the dynamic and fluctuating loading effects of the wind on the 
metal roof membrane and its fasteners to resist and their resistance to 
the applied stresses and forces on these elements in high wind areas. 
In addition, in the Department's report on damage assessment to 
manufactured homes caused by Hurricane Charley, it was noted that the 
roof and walls performed significantly better for the post-1994 homes, 
in which metal roofing systems were not used, as compared to homes 
constructed prior to the effective date of the standards for high wind 
protection. The State of Florida also concluded from its field 
investigations following last year's devastating hurricanes, that one-
piece membrane roofs did not perform well, that inadequate fastening of 
metal roofs allowed a large percentage of them to be blown off 
manufactured homes that were built prior to the implementation of the 
wind standards in 1994. This, the State said, may have led to the total 
loss of these homes. HUD engineers inspecting the damage caused by the 
hurricanes in Florida also observed numerous failures of metal roofing 
systems used in pre-1994 constructed homes. In view of the above 
concerns, the final rule requires HUD approval of test methods for one-
piece metal roofing systems. However, the Department would be willing 
to reconsider this decision, if a voluntary consensus test standard 
were to be developed that would adequately assess the wind effects on 
one-piece metal roofing membranes and their fastenings.
    2. The December 1, 2004, proposed rule would have amended Sec.  
3280.305(c)(3) by incorporating a new paragraph (iv) to add a roof load 
requirement for skylights of the zone for which it is designed.
    Comment: The skylight load requirements described in Sec.  
3280.305(c)(3) are a good idea. Two commenters wrote that the skylight 
load requirements establish necessary performance requirements for 
skylights.
    HUD Response: The Department agrees and is including the proposed 
roof load performance requirements for skylights in this final rule.
    3. The December 1, 2004, proposed rule would have amended Sec.  
3280.305(e) by clarifying the required performance of fasteners and the 
connecting mechanisms for joining the major structural elements of 
manufactured homes, and would specify a continuous load path for 
imposed forces to the home's foundation/anchorage system.
    Comment: The load path for foundation and anchorage systems 
described in Sec.  3280.305(e)(1) is a good

[[Page 72027]]

idea. One commenter wrote that the proposal for foundation and 
anchorage systems provides consistency within the industry.
    HUD Response: The Department agrees and is including the proposed 
revision to the current requirements for fastening of structural 
systems in the final rule.
    4. The December 1, 2004, proposed rule would have amended Sec.  
3280.305(e)(2) by reducing the minimum thickness requirements for steel 
strapping or brackets required in Wind Zones II and III from 26 gauge 
(0.0179'') to 0.016''.
    Comment: The proposed reduction in steel strapping requirements 
described in Sec.  3280.305(e)(2) should be accepted and additional 
testing is not needed. One commenter wrote that additional requirements 
for testing in high wind regions are not required and should not be 
imposed. The commenter wrote that past instances of staples 
inadvertently driving through metal strapping of lesser thickness may 
reoccur should this proposal go into effect. One commenter asked if the 
DAPIA accepts these design changes to reduce the minimum thickness of 
steel strapping for Wind Zones II or III, then why would additional 
testing to verify changes of this nature be required? As long as the 
DAPIA is satisfied, there should be no reason to require further 
testing. Two other commenters recommended that the final rule does not 
need to require ``suitable load testing.'' HUD has always allowed 
calculations and analyses to be used instead of testing. Testing, while 
more specific than calculations, is generally less conservative. It is 
generally understood that HUD will not allow testing of simple 
assemblies that can be easily calculated. Some of the connections used 
in high wind regions would fall into this situation and need to be 
calculated anyway. This change is also consistent with the preference 
to use ``performance requirements'' set forth in Sec.  3280.1. Another 
commenter wrote that a manufacturer should be allowed to choose to 
utilize larger brackets, more fasteners, and stronger strapping to 
allow for greater spacing of the anchors and should not be penalized 
through prescriptive requirements. Another commenter wrote that it is 
not clear why critical connections cannot be justified by calculations 
or tests acceptable to the DAPIA and that it may be confusing as to 
which connections are ``critical,'' since it would seem that most 
connections are critical for all wind zones. The Manufactured Home 
Construction and Safety Standards already require a Professional 
Engineer or Architect to seal all Wind Zone II/III calculations, tests, 
and details.
    HUD Response: The final rule permits the use of thinner .016 inch 
steel strapping or engineered connectors provided they are installed at 
24 inches on center in Wind Zone II and 16 inches on center in Wind 
Zone III. The final rule also permits a combination of strapping or 
engineered connectors and structural rated sheathing or structural 
rated wall sheathing alone when it overlaps the roof and/or floor and 
is substantiated by either engineering calculations or suitable load to 
tests.
    5. The December 1, 2004, proposed rule would have amended Sec.  
3280.305(g)(3) by requiring wood panel products used as floor or 
subfloor materials on the exterior of the home to be rated for exterior 
exposure and be protected from moisture by sealing or applying 
nonabsorbent overlay with water resistant adhesive.
    Comment: The floor rating and moisture requirements described in 
Sec.  3280.305(g)(3) are not a good idea. One commenter wrote that the 
proposed body and frame requirements will not provide the protection 
desired. The exterior rated floor materials provide protection only 
during the construction process. Therefore, the sought-after extended 
life of the material is not achieved.
    HUD Response: The final rule requires wood panel products used as 
flooring or sub-flooring on the exterior of the home to be rated for 
exterior exposure and be protected from moisture by sealing or by 
applying a nonabsorbent overlay with a water resistant adhesive. HUD 
does not agree with the commenter regarding the extent or period of 
protection from the requirement that panels be exterior rated, as these 
panels will require the use of moisture-resistant adhesives in their 
construction that will enhance their durability. These added provisions 
will also provide protection against deterioration of exterior floor 
decking materials that are exposed to moisture. In particular, when 
materials such as particleboard become saturated with moisture, 
significant structural damage can occur. In addition, the requirement 
that panel products be rated for exterior exposure will assist in 
identifying those materials that are suitable for use in exterior 
applications.
    6. The December 1, 2004, proposed rule would have amended Sec.  
3280.306(b) by requiring that each column support pier location 
required along the marriage line(s) of multi-section manufactured homes 
be identified at each location by paint, label, or other acceptable 
methods.
    Comment: Identifying the marriage column support locations as 
described in Sec.  3280.306(b) is not a good idea. One commenter stated 
that the drawings and specifications provided with each home already 
show the required locations for the centerline pier supports and are 
available to the retailer, installer, and consumer prior to the 
delivery of the home. The foundations or support systems for today's 
multiple section manufactured homes are largely prepared before the 
arrival of the home on the home site. Thus, the markings and their 
associated costs will be fundamentally wasted. The proposal would 
further require that the marking be visible after the home is installed 
even though properly placed foundation supports will mask the markers 
from view. This change would place too much reliance on the correct 
placement of the proposed markers.
    Two commenters wrote that identifying the marriage column support 
locations described in Sec.  3280.306(b) is a good idea and that the 
recommendation will improve home installation compliance and 
subsequently improve the longevity of manufactured homes at a minimal 
cost to the homeowner. Marriage wall column support location errors are 
one of the major problems found during installation inspection. One of 
the commenters also wrote that the requirements would improve home 
installation compliance and subsequently improve the longevity of 
manufactured homes at a minimal cost to homeowners. In addition, 
members of the DAPIA Technical Advisory Group, at its March 2005 
meeting, recommended that other pier locations, such as perimeter and 
shear wall support locations required by the manufacturer's designs and 
instructions, also be identified.
    HUD Response: The final rule requires identification of each column 
pier support location along the marriage line, as well as for each pier 
location required along the perimeter of the home, each required shear 
wall support location, and other special pier support locations 
specified in the manufacturer's instructions.

Formaldehyde Health Notice Comments

    HUD did not accept and include in the December 1, 2004, proposed 
rule, MHCC's recommendation that would have removed the Health Notice 
on formaldehyde emissions (the Health Notice) currently required by 
Sec.  3280.309 of the Construction and Safety Standards.
    Comment: The decision to continue to post the Health Notice in each 
manufactured home as described in

[[Page 72028]]

Sec.  3280.309 is contradictory to MHCC's recommendation. One commenter 
wrote that HUD rejected the proposed MHCC recommendation not to 
prominently display the Health Notice in each manufactured home. The 
commenter stated that, contrary to HUD's assertion that MHCC did not 
provide any data supporting its recommendation to remove the 
requirement, MHCC discussed this issue with HUD at MHCC meetings in 
2004, and reviewed several documents related to formaldehyde. The 
commenter stressed that it is not recommending any changes to the 
current standards regarding the formaldehyde emission controls; the 
commenter is only recommending changes to the Health Notice. The 
commenter continued by stating that all of this information was 
considered by MHCC in coming to its decision to require that the Health 
Notice on formaldehyde be placed in the homeowner's packet rather than 
having it prominently displayed in the home.
    A commenter wrote that the decision to continue to post the Health 
Notice in each manufactured home as described in Sec.  3280.309 
stigmatizes the manufactured home industry. The commenter is 
disappointed that HUD did not issue for public comment the proposal to 
eliminate the requirement for the Health Notice to be placed in 
manufactured homes. Manufactured homes are the only homes in America 
that must display these notices and they stigmatize manufactured homes. 
Another commenter wrote that the formaldehyde notice serves only as a 
sales deterrent, while contributing to existing misunderstanding by the 
public regarding health-related issues associated with formaldehyde. 
The commenter urged HUD to reevaluate its decision on the Health Notice 
and put it forth for another round of public comment. One commenter 
wrote that this notice shouldn't be displayed so prominently and asked, 
``Why should it be the first thing a prospective buyer sees when they 
enter a new manufactured home?'' Another commenter wrote that for the 
past 20 years formaldehyde levels in manufactured housing have declined 
so that they are no higher than in any other residential structure. The 
manufactured home product and materials used to construct it have 
progressed to the point where the need for a displayed Health Notice 
``only contributes to the public's notion that manufactured homes are 
somehow ``inferior'' to other types of housing.'' Other commenters 
suggested that if such a warning is still deemed necessary, then the 
warning should be included in the Homeowner's Manual with an 
explanation that all homes contain some amounts of formaldehyde.
    Some commenters wrote that the decision to continue to post the 
Health Notice in manufactured homes as described in Sec.  3280.309 
ignores current and available scientific evidence that formaldehyde 
emissions have been greatly reduced. HUD should reconsider its 
rejection of MHCC's proposal in light of current research that is 
available to support MHCC's recommendation. Specifically, three 
commenters wrote that the Manufactured Housing Research Alliance (MHRA) 
has produced the most recent and up-to-date study on the health risks 
of formaldehyde in manufactured homes. ``Formaldehyde Concentrations in 
Manufactured Homes: The Current Situation'' (July 2004) investigates 
this issue from several different aspects and shows that formaldehyde 
should no longer pose any greater concern than in conventional housing. 
One commenter continued by stating that ``[e]ven though it is only one 
paper, it is a summation of many other studies that are more current 
than the ones used by HUD almost 20 years ago when the notice became 
part of the Standards.'' The commenter wrote that the language of the 
Health Notice refers to the Ventilation Option, which was deleted in 
1994. This Ventilation Option, formerly Sec.  3280.710(g), was replaced 
by the Additional Ventilation requirement in Sec.  3280.103(b). Another 
commenter wrote that consumer formaldehyde complaints have been 
essentially eliminated. Another commenter wrote that it is ``common 
knowledge'' that formaldehyde emissions in manufactured homes have been 
dramatically reduced since the requirement for the Health Notice was 
first imposed. Additionally, the commenter claimed that HUD implied 
that only manufactured homes are permitted to use construction 
materials containing urea-formaldehyde (UF) resins, and that this 
assertion is untrue as the commenter is not aware of such a restriction 
for modular or site-built homes. One commenter stated that the removal 
of the Health Notice would likely be supported by the findings in 
National Institute of Standards and Technology's (NIST) IAQ 
manufactured housing research with HUD's Healthy Homes Program and 
asked whether HUD consulted with NIST before rejecting MHCC's proposal.
    Two commenters submitted six points to illustrate that data does 
exist showing that formaldehyde levels in today's manufactured homes 
have changed in the 20 years since Department regulations were 
implemented. Specifically, the six reasons listed are: (1) Gypsum 
wallboard has replaced the UF bonded plywood as the interior wall 
covering of choice; (2) maximum formaldehyde emissions from UF bonded 
plywood and particleboard wood product materials has been drastically 
reduced; (3) the HUD Code is the only model building code that 
regulates formaldehyde emissions levels, which makes it not likely that 
either manufactured home builders or homebuyers would develop a rare 
nasal cancer; (4) the HUD Code ventilation requirements increase the 
volume of indoor air exhausted from the home, which can dilute any 
indoor air pollutants; (5) one of the original reasons for singling out 
HUD Code homes as having formaldehyde problems was the small home size; 
now, however, as floor size increases, the volume of air in the living 
space increases, and the dilution of air borne contaminants can be 
reduced; and (6) the measured concentration of formaldehyde levels has 
been on a downward trend since 1985.
    HUD Response: HUD had not accepted for inclusion in the proposed 
rule MHCC's proposal to remove the requirement to temporarily post a 
Health Notice on formaldehyde emissions in each manufactured home (24 
CFR 3280.309), because HUD has not found it supported by a sufficient 
factual and scientific record. As indicated in the proposed rule, a 
determination to discontinue the Health Notice would require a similar 
level of factual and scientific support that was provided to HUD when 
the rule was being promulgated. As also indicated in the proposed rule, 
HUD recognizes that improvements have been made in particleboard and 
plywood panel processing resulting in lower emission levels than from 
panels bonded with UF resin systems that were available at the time of 
the implementation of the Department's formaldehyde emission control 
requirements. HUD also recognizes that the measured formaldehyde 
concentration levels in manufactured homes produced since 1985 is 
significantly lower than in homes built prior to the implementation of 
the Construction and Safety Standards. HUD is also aware, however, that 
the sample of homes studied, as indicated in the MHRA report referenced 
in the comments [``Formaldehyde Concentrations in Manufactured Homes, 
The Current Situation''] is extremely small in comparison to the large 
number of homes produced during the same period

[[Page 72029]]

and that the sample of homes studied were subject to a variety of 
testing parameters and measurement methods. This leaves some question 
as to the statistical validity and overall confidence in the test 
results due to the relatively small sample size of homes evaluated. 
Further, even the MHRA report states: ``The health consequences of 
various formaldehyde levels continue to be a topic of debate among 
researchers. Particularly, at very low concentration levels (below 
0.1PPM) there is no consensus on safe levels of durations of 
environmental formaldehyde exposure.'' However, as indicated in the 
preamble of the final rule on formaldehyde in 1984, there is a sector 
of the population that has greater sensitivity to and is at more risk 
of formaldehyde's irritant effects and that will react adversely to 
formaldehyde at extremely low levels of exposure. This includes the 
elderly, young children, and individuals with a history of asthma, 
allergies, or lung problems. The purpose of the Health Notice is to 
advise prospective purchasers that the home contains materials that 
emit formaldehyde and to describe acute symptoms that may occur under 
formaldehyde exposure for those individuals who may be at greater risk.
    However, as indicated in the preamble of the proposed rule, HUD 
will continue to study the formaldehyde issue--including reviewing any 
new scientific evidence--and intends to consult with the Consumer 
Product Safety Commission, the Environmental Protection Agency, and the 
Department's Office of Healthy Homes to study the health risks to 
occupants at current formaldehyde exposure levels to determine if any 
regulatory controls are still needed to limit formaldehyde emissions in 
manufactured homes. As part of its review and evaluation, HUD will also 
consider the requirements of other building codes as they may relate to 
formaldehyde exposure and indoor air quality for single-family 
residential construction. HUD intends to work with MHCC in developing 
and supporting any further rulemaking proposals on formaldehyde.

Roof Truss Testing Requirement Comments

    Based on the recommendations of MHCC, the December 1, 2004, 
proposed rule would have amended Sec.  3280.402 by providing more 
stringent initial qualification of truss designs and by expanding and 
clarifying the requirements for follow-up testing to better ensure that 
subsequent production of trusses will meet the requirements of the 
Construction and Safety Standards.
    Comment: The test procedures for roof trusses, as described in 
Sec.  3280.402, should be severed from the remaining proposals, 
rejected by HUD, and remanded to MHCC for further consideration. One 
commenter wrote that the revised test protocol will lead to destructive 
testing and could limit truss designs that would ultimately pass the 
non-destructive test. Certain truss designs could be eliminated. The 
best route to take is to send the proposal back to MHCC for further 
study. If these revised test protocols are implemented by final 
rulemaking, the industry might have to go to totally engineered truss 
designs, which would be more expensive for the industry. Another 
commenter stated that the recommended revisions were extracted from the 
proceedings of the consensus committee and the National Fire Protection 
Association (NFPA) NFPA 501 Standard on Manufactured Housing, which 
were based on research conducted by the National Association of Home 
Builders Research Center (NAHB-RC). The commenter further stated that 
neither organization had a mandate to consider cost-impact in proposing 
standards or formulating the recommendations from its studies. Similar 
concerns were expressed about the NFPA 501 Standard on Manufactured 
Housing from which these proposals were derived.
    Another commenter wrote that concerns have been expressed by and to 
MHCC members about the more stringent qualification testing of truss 
designs that have been talked about and supported by the industry, code 
development work groups, and task forces over the last ten years. The 
commenter stated MHCC's consensus development process lacked adequate 
consideration of the true costs associated with the adoption of this 
proposal, the impact these changes may have on the testing procedures 
and the industry, and the proposal's impact on roof truss home design 
and future innovation. The commenter asked that HUD remove this 
recommendation from the rule and return the proposal to MHCC for 
further consideration and development.
    One commenter wrote that the test procedures for roof trusses, as 
described in Sec.  3280.402, are not consistent with statutory 
directives. Although the proposed rule's wording closely follows the 
text found in NFPA 501, Standard on Manufactured Housing, published by 
NFPA, the NFPA standard is not in use for manufactured housing and the 
NFPA is not under a mandate from Congress to protect the affordability 
of manufactured housing. NFPA 501 and the proposed rule are 
inconsistent with the model building codes currently in use for site 
constructed home and factory built modular homes. NFPA 501 and this 
proposal require excessive data collection and a more stringent 
recovery deflection limit. Additionally, the commenter stated that the 
cost of Sec.  3280.402 will adversely affect the affordability of 
manufactured housing and will stand as an obstacle to the 
accomplishment and execution of section 602(b)(2) of the Act, which 
states that a purpose of the Act is to ``facilitate the availability of 
affordable manufactured homes and to increase home ownership for all 
Americans.''
    One commenter wrote that the new roof truss test procedures as 
described in Sec.  3280.402 will not be cost-effective. Eliminating the 
option of 1.75x overload ends one cost effective way of building the 
homes at the lower end of the manufactured housing market and will 
place additional costs on sections of the market that can least afford 
it. Two commenters wrote that the change to the testing procedure will 
cost much more than the $77.28 cited by HUD. The commenters stated that 
their truss suppliers place the price per truss for Wind Zone I at 15 
to 25 percent, making the eventual cost to the consumer about $325 `` 
far more than the $77 cited by HUD. Other commenters wrote that 
deleting the 1.75 proof load test for roof trusses will increase truss 
member sizes, thereby increasing the cost of trusses by up to 25 
percent. This additional cost may add up to $600 per home. One 
commenter wrote that increased top and bottom chord sizes could raise 
overall depths of trusses, as well as the transportation height of the 
home. In the Eastern United States, where overpasses are low, homes 
will need to be rerouted, resulting in increased shipping costs of $800 
and beyond. Finally, another commenter wrote that the recommended 
revised truss test protocol needs further study and evaluation before 
implementation. The commenter stated that many truss suppliers have 
indicated that there may be a 25 percent increase in costs for truss 
design and testing depending on the style of roof design being 
considered. Every truss design would need to be re-qualified under the 
test procedures, and cost estimates run from $200 to $500, far more 
than the $77.28 per home as indicated.
    Two commenters asked specifically why the new roof truss test 
procedures as described in Sec.  3280.402 are needed. The commenters 
wrote that they do not see any information indicating that

[[Page 72030]]

trusses are failing. They further inquired whether the study referred 
to in the proposal was conducted during the 1980s? If so, today's 
trusses are much improved from the trusses referred to in that study. 
Also, deleting the 1.75 proof tests will limit existing designs and 
prevent new innovative designs by increasing the top and bottom chord 
sizes. This deletion will create criteria that are more stringent than 
and inconsistent with those model building codes that require only a 
minimum test period of ten seconds for test loads equal to 1.5 times 
the design wind load. Two commenters wrote that these new criteria will 
create a huge backlog in truss retesting and redesign, adding to the 
costs that could be passed on to the consumer. Further, assuming the 
time frame to perform this task is set at 180 days, that is not enough 
time to complete the reviews, retests, and approvals. Two commenters 
wrote that low-sloped cathedral designs, which are common in the 
industry, will be eliminated. One commenter wrote that the proposed 
truss testing change should be returned to MHCC for further evaluation. 
The same commenter wrote that HUD should continue to allow the 1.75 
proof load test, because the added costs of eliminating this acceptable 
test do not appear to be offset by safety considerations.
    One commenter wrote that the requirement that deflection of bottom 
chord be measured, at a minimum, at the truss midspan and panel points 
is overly burdensome and completely unnecessary. The commenter stated 
that for many trusses, this requirement would result in a minimum of 
nine or ten points of deflection measurement during testing, and it is 
difficult to obtain these deflections with dead load hanging from the 
bottom chord of the truss at 12 inches on center. Several commenters 
wrote that measuring deflection at each panel point, mid-span of the 
truss, and mid-span between each panel point is not necessary and that 
the current checks at quarter points and mid-span should be more than 
sufficient. A third commenter wrote that this change will significantly 
increase the time to perform truss testing and will increase the cost 
to perform required truss testing for each truss design.
    One commenter wrote the dead load test procedures as described in 
Sec.  3280.402(d)(1) are too expensive and not necessary. HUD should 
revise the new proposed requirement to add dead load to both the top 
and bottom chord of the truss so that this is only required if the 
actual bottom chord dead load exceeds 5 psf; otherwise, allow the 
entire dead load to be applied to the top chord as is currently 
permitted. For small bottom chord dead loads (up to and including 5 
psf), this added step is not necessary and needlessly adds to the cost 
of testing.
    Another commenter wrote that the live load test procedures as 
described in Sec.  3280.402(d)(2) are dangerous. In 1994, HUD and NAHB 
ran proficiency tests comparing tests that pulled on the top chord to 
test in the inverted position. The tests determined that pulling on the 
top chord was difficult, impractical, dangerous, and yielded 
inconsistent results. It was determined that testing the truss in the 
inverted position provides adequate results. Testing in accordance with 
existing uplift requirements is simple and provided consistent results. 
Testing uplift in accordance with the new HUD proposal will have a 
significant cost impact on the truss approval process. The set-up 
procedure will take three to four times longer, which will increase the 
cost for testing a new design substantially. All modifications to truss 
testing should be delayed until such studies can be prepared for 
review.
    One commenter wrote that the overload phase as proposed in Sec.  
3280.402(d)(4) is too stringent. The test procedure for the overload 
phase would be increased to dead load plus 2.5 times the live load. 
Although this more stringent truss loading criteria has already been 
adopted by some manufacturers, combining this with the more stringent 
deflection acceptance criteria may cause some truss designs to fail 
that would otherwise be acceptable under the existing provisions.
    Several commenters wrote that the acceptance criteria for truss 
designs, as proposed in Sec.  3280.402(d)(5), are too conservative, 
inconsistent with building codes, and too expensive. The recovery 
deflection of L/480 within five minutes after live load removal is too 
conservative and many manufacturers have permitted up to four hours of 
recovery time to qualify truss designs. Another commenter wrote that 
the recovery requirement is inconsistent with the model building codes, 
which require recovery of not less than 75 percent of the maximum 
deflection within 24 hours after removal of the load. Another commenter 
wrote that HUD should remove the requirements to measure no load to 
dead load deflection and the limit for the same, because this is a 
totally meaningless requirement. The deflection from no load to dead 
load is normally compensated for by building camber into the truss. 
This added step will add needless cost to the test procedure. The 
commenter requested that HUD revise the proposal for up to four hours 
for recovery deflection to reach L/480 or better. The commenter 
explained that five minutes may not be adequate time to allow recovery 
to occur and could eliminate otherwise acceptable designs thus adding 
cost. Some of the proprietary criteria in use today by some home 
manufacturers specifies four hours and ``is working fine without 
problems.''
    One commenter wrote that the uplift load test procedure for roof 
trusses as proposed in Sec.  3280.402(e) makes it difficult to test and 
require a change of testing facilities. The test procedure for overload 
phase requirements increased to 2.5 times the new uplift load for one 
minute, which is an increase from the 1.75 overload factor of the 
current standard. Additionally, the test procedure has been revised to 
provide uplift to the top chord of the truss design and not the 
existing test set-up of inverting the truss and pushing down on the 
bottom chord. Truss designs may not be able to be tested due to their 
current configuration and may not provide flexibility in testing for 
the tension device placement as a 12-inch spacing might provide. Also, 
no testing facility that currently qualifies HUD Code home roof trusses 
would be capable for testing trusses as described by the revised test 
protocol without a lengthy process to change the test set-up. Another 
commenter wrote that there have been no documented truss failures due 
to existing design criteria since the uplift testing went into effect 
in 1994. The HUD proposal for testing uplift requires 1'' wide straps 
attached around the top chord at 6'' o.c. In some cases, truss designs 
with closely spaced verticals and webs will be physically impossible to 
test to the 6'' requirement. This requirement would limit truss design 
and innovation. Pulling up on straps at 12'' o.c. provides the same 
uplift load and similar results as pulling on the uplift straps 6'' 
o.c. Additionally, the proposed method requires cylinders spaced at 
12'' o.c., to apply 6'' o.c. uplift strapping. This will require some 
truss manufacturers to redesign their current truss testing equipment, 
which commonly has cylinders at 24'' o.c. This retrofit will be costly 
and time consuming. One commenter wrote that compliance with the 
requirement cannot typically be achieved at panel point because of the 
width of connector plates. One commenter supported the conversion of 
the uplift test to a more reasonable appropriate uplift test. The 
commenter wrote that the spacing of the uplift points, however, appears 
to be too conservative. Instead of every 6'', it

[[Page 72031]]

seems that every 12'' would be sufficient and be easier to convert 
existing testing equipment with hydraulic cylinders at 24''.
    Finally, commenters urged HUD to allow a lengthy, reasonable time 
period for phase-in of the new requirements for truss testing similar 
to what has been done in the past. It is hoped that HUD will allow 12 
months for all testing to be completed.
    HUD Response: In view of comments received from the public, the 
Department is returning this proposal on truss testing procedures to 
MHCC for further consideration and requests the following be considered 
by MHCC during its deliberations:
    1. Whether the non-destructive testing procedure for roof trusses 
that permits a lower overall safety factor to be used in conducting the 
tests based on a presumed low failure rate for roof trusses should be 
eliminated.
    MHCC could consider including the non-destructive procedure, if 
adequate safeguards are provided to assure that initial qualification 
tests would be conducted using minimum quality of materials and 
workmanship or if a statistically valid sample of trusses is tested in 
lieu of the minimum requirements. In addition, enhanced follow-up 
testing provisions would be needed to account for the lower factor of 
safety of 1.75 currently permitted by the non-destructive testing 
procedure.
    2. The need for the upright tension tests to evaluate the uplift 
resistance of the trusses.
    Tests conducted by the NAHB Research Center indicated that trusses 
tested in the inverted position consistently failed at average loads 
greater than trusses tested in the upright position and had lower mid-
span deflections than trusses tested in the upright position. In 
addition, the failure modes were different for some truss designs when 
tested in the upright position as compared to the inverted position.
    3. Should the factor of safety for uplift testing be reduced from 
2.5 to the current requirement of 1.75 times the design wind pressures 
in consideration of comments received regarding safety during testing.
    4. The costs associated with any recommended revisions to the truss 
testing requirements.
    HUD's decision to not make final the proposed rule section, as 
recommended by MHCC, is consistent with the record of comments received 
from the public, including MHCC itself (the Committee having 
reconsidered its prior position). However, HUD views truss testing 
procedures as too important a safety matter to leave unaddressed. The 
standards in place (i.e., reflected in the current regulations) have 
not been modified in many years. The issue, having been raised, needs 
to be examined to determine whether, in fact, existing standards are 
adequate to protect homeowners in all geographic areas of the country. 
Accordingly, HUD anticipates MHCC will expeditiously re-evaluate and 
resubmit proposed truss testing procedures. HUD will work closely with 
MHCC in evaluating any new proposals for truss testing procedures and 
may amend HUD's requirements, as necessary, in a future rulemaking.

Thermal Protection Comments

    The December 1, 2004, proposed rule would have amended Sec.  
3280.504(b) to codify certain provisions of a waiver that permits 
manufactured homes intended to be sited in humid climates to have the 
vapor retarder installed outside of the home's thermal insulation.
    Comment: The proposed condensation control and installation of 
vapor retarders described in Sec.  3280.504(b)(4) is not practical and 
should provide exceptions. Several commenters stated that HUD should 
provide more exemptions, including: (1) Kitchen back-splash materials 
of less than 50 square feet in the area installed around countertops, 
sinks, and ranges; (2) bathroom tub areas and shower compartments; (3) 
cabinetry and built-in furniture, in any location; and (4) hardwood 
wall paneling used under chair rails in dining room areas, less than 50 
square feet in area. One commenter explained that these construction 
features are commonly installed against exterior walls of manufactured 
homes and do not represent a large exposed wall where condensation due 
to the hot-humid climates would appear to be excessive. Also, a 
September 2000 MHRA study revealed that hardwood paneling is not 
detrimental to the established proposal waiver requirements of a 
minimum 5.0 perm rating. Another commenter wrote that it is absolutely 
necessary to provide some minor exception to the requirement that the 
interior finish have a combined permeance of not less than 5.0 perms. 
MHCC has already discussed with HUD the need to include these 
exceptions, which are part of further changes to the Construction and 
Safety Standards that have been approved by MHCC. These changes are in 
concept but have not yet been put into proposed rule form. The vapor 
retarder location specified in Sec.  3280.504(b)(4) is an alternative 
to that called for in Sec.  3280.504(b)(1) and therefore could not be 
used with a vented wall cavity specified in Sec.  3280.504(b)(3). From 
a practical-usability standpoint, in order for the alternative vapor 
retarder location to be of any use at all, some minor exceptions are 
absolutely necessary to the requirement that the interior finish have a 
combined permeance of not less than 5.0 perms. These exceptions were 
recommended by MHCC and are also embodied in the NFPA-501 2003 edition 
at section 8.4.2.1.6. Another commenter wrote that the requirement to 
have the interior finish have a combined permeance of not less than 5.0 
perms makes good sense, but a set of exceptions is necessary, because 
it is impractical to build a home with all interior surfaces at 5.0 
perms or more. Without these exceptions, no manufacturer will be able 
to place the vapor barrier on the outside in the appropriate zones. HUD 
had similar wording in its April 2002 waiver, but without these 
necessary exceptions. As a result, virtually no manufacturer has been 
able to use the waiver. The only reason to restrict the permanence of 
the interior surfaces is to make sure any moisture that gets past the 
exterior barrier is able to exit the wall to the interior. These few 
suggested exceptions will not trap moisture in the wall. In fact, some 
materials are usually not tight-fitted against the framing; therefore, 
moisture should easily escape the cavity. The commenter also wrote that 
other building codes have no interior wall restrictions at all 
associated with vapor barriers. For instance, 2003 IBC--article 1403.3, 
2003 IRC--article R318.1, and 2003 IECC--article 502.1 make no mention 
of interior perm ratings. HUD should allow these exceptions so the 
industry can catch up to present building science. Without these 
exceptions, the vapor barrier will remain on the inside in the hot, 
humid climate and moisture will be trapped in the home.
    HUD Response: HUD agrees with many of the comments; therefore, the 
final rule in Sec.  3280.504 now includes exceptions to the 5.0 perm 
requirement for interior finish materials of up to 50 square feet in 
area.
    Comment: The focus of Sec.  3280.504(b)(4) should be reducing air 
movement rather than vapor retarders. One commenter wrote that Sec.  
3280.504(b)(4) does not address any effective construction measure to 
reduce the larger problem of air movement into the wall cavity. In 
fact, the performance measure that would impact the reduction of air 
movement would be the use of a continuous air barrier. Homes with low 
permeable sheathings have

[[Page 72032]]

been observed in the Gulf Coast, and they have experienced moisture 
problems because the wood sheathing is installed with a required gap to 
allow for expansion and contraction. These expansion and contraction 
seams should be the focus, not just vapor pressure. The much larger 
problem involves large pressure swings in homes where mechanical 
equipment is operated.
    HUD Response: HUD and MHCC may consider developing, in a future 
rulemaking, requirements for the use of continuous air barriers for 
exterior walls and requirements for expansion and contraction gaps in 
wall sheathing to reduce the amount of air movement in exterior wall 
cavities.
    Comment: Ventilated walls as described in Sec.  3280.504(b)(3) are 
not a good idea because there is no ventilation rate or calculated 
method shown that provides a minimum performance to reduce the amount 
of moisture. Also, whole-house testing has shown that air movement 
created by negative pressure draws moisture through construction seams. 
The creation of even more pathways by ventilating the wall will allow 
even more moisture to be drawn into the walls.
    HUD Response: HUD, in coordination with MHCC, may consider, in a 
future rulemaking, eliminating the current alternative for controlling 
condensation in exterior wall cavities as is currently permitted in 
Sec.  3280.504(b)(3) of the Construction and Safety Standards.
    Comment: Reference to the American Architectural Manufacturers 
Association (AAMA) 1500 standard in Sec.  3280.508(e) should be changed 
to the National Fenestration Rating Council (NFRC) 100 Standard. One 
commenter wrote that the final rule should eliminate reference to AAMA 
1500 for the following reasons: Because the majority of manufacturers 
have moved to NFRC; the NFRC is supported by United States Department 
of Energy (USDOE) and Energy Star; HUD is the only federal agency still 
relying on AAMA 1500 thermal performance; and NFRC-100 labels provide 
consumers, plant, and IPIA data on the window, while the AAMA label 
does not provide that data.
    Another commenter wrote that the proposed rule to permit window 
manufacturers the alternative to use NFRC 100 to rate window energy 
performance is a step in the right direction.
    HUD Response: The final rule permits the use of either reference 
standard for rating window or glazing products for thermal 
transmittance and resistance to condensation.

Plumbing Systems Comments

    The December 1, 2004, proposed rule would have amended Sec.  
3280.607(a) to require restricted flow faucets and showerheads and add 
a paragraph (b) to require the use of low water consumption toilets.
    Comment: The proposal is consumer-friendly. Two commenters wrote 
that technology has improved low water consumption fixtures and 
faucets, so it is a sound proposal.
    HUD Response: The final rule requires the use of low consumption 
water fixtures and toilets as indicated in the proposed rule.

Heating, Cooling, and Fuel Burning Requirement Comments

    As recommended by MHCC, the December 1, 2004, proposed rule would 
have amended Sec.  3280.709 by requiring the installation of a 
corrosion-resistant water drip collection and drain pan under each 
water heater.
    Comment: The requirement was not developed with any justification 
and should be dropped. One commenter requested that this section be 
deleted. The commenter wrote that it believes that the proposal has not 
been developed in compliance with the HUD Final Information Quality 
Guidelines published in the November 18, 2002, Federal Register Notice. 
Specifically, the HUD Guidelines provide in Section VI that 
``information [HUD] disseminates to the public is objective, useful, 
and has integrity.'' HUD has not presented any information to justify 
this requirement, including any economic or technical justification for 
the addition of a corrosion-resistant water drip collection and drain 
pan to be installed under each water heater. In addition, such a 
requirement will result in problems of installation, cost, drainage, 
and, for fossil fuel type water heaters, can result in the blockage of 
combustion air openings for water heaters that obtain combustion air 
from the bottom of the unit, a very typical manufactured home 
application.
    Some commenters wrote that a drain pan would impede air flow into 
the water heater. One commenter wrote that to install a drain pan under 
the water heater would restrict the ability of the water heater to 
receive the proper amount of combustion air. Moreover, doing so would 
require modifications to the design and construction that could 
significantly increase the costs without any economic justification. 
Another commenter wrote that one-half of the gas-fired water heaters 
sold for installation in manufactured homes are of the direct vent 
design. This requires all air for combustion to enter the water heater 
d