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Re: Conventional Framing Concerns - A letter to NAHB

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Dennis, I believe the answers to your questions about an engineered approach to
conventional construction are covered in the Wood Frame Construction Manual
(WFCM) published by the American Forest and Paper Assn. (AF&PA) in Washington,
DC.  It has both engineered and prescriptive provisions, and all framing,
connections, shear wall and truss hold-downs, etc. are covered based on a
complete computer-engineered analysis for residential buildings of all
configurations up to a fairly large size.  The manual covers high wind regions
and Seismic Zones 0-4.  And yes, there were a few surprises along the way.  I
believe this manual is being used for conventional construction upgrades for the
IRC.  NAHB Research Center is also well aware of this manual.
John Rose/APA, Tacoma

Dennis S. Wish wrote:

> To Mr. Jay Crandell
> HATDE: Housing Affordability Through Design Efficiency
> National Association of Home Builders
> (1-800-638-8556) or jcrandell(--nospam--at)nahbrc.org
>
> I would like to invite you to join the SEAOC Listservice. It is very
> beneficial that you do since many of our discussions relate to our
> professional concerns over the inadequacy of Conventional Framing standards
> in High Wind and Seismic areas of the country. There is no charge to join
> the listservice. You need only send an email message to admin(--nospam--at)seaoc.org and
> in the body of the message type "join seaoc" (without the quotes).
>
> FOR SEAOC LIST MEMBERS READING THIS POST, PLEASE REFER TO NAHB WEB SITE FOR
> NATDE AT http://www.nahbrc.com/homebase/techbrfs/hatde.htm.
>
> I suggest you visit the SEAOC web page at seaoc(--nospam--at)seaoc.org and work your way
> to our listservice archives. Please search the topics for Conventional
> Framing and our latest thread entitled "Architects doing Engineering".
> We have some very strong issues with the Conventional Framing Section of the
> '94 and '97 UBC. Our concerns are not diminished much by the draft of the
> IBC - however, many of us feel that it is an improvement.
> Some concerns include:
> 1) The lack of completion of prescriptive measures to guide non-professional
> users of this code. For example, where in the code does it provide
> prescriptive tables for the design of headers.
> 2) A non-engineered prescriptive measure in the code should allow for the
> minimum standards of safety that are equivalent to or exceed an engineered
> solution. The current provisions of Conventional framing provide a much
> reduced minimum standard for building products produced under this code
> provision. This will equate, not in life safety issues, but real economic
> concerns as the cost of repair exceeds those of damaged engineered products.
>
> Jay, I am not trying to sell engineering over prescriptive measures, but am
> trying to assure that the provisions that the non-professional follows is
> equivalent to an engineered solution and provides enough information to
> adequately build the structure and minimize the chance of structural failure
> or unreasonable potential repair costs.
>
> One issue that the code creators did not contend with is the lack of
> disclosure provisions that educate the potential home-buyer as to the level
> of performance that the home was designed for. I live in the Palm Springs
> California area and specialize in residential construction. Many homes in my
> neighborhood are constructed by developers who follow Conventional framing
> standards to maximize their profits. They market their homes in the same
> price range as comparably sized engineered homes, but lack the holddowns,
> anchor bolts, and shear resisting elements required by engineered standards.
> Considering the floor plans are equivalent (there are only a number of plans
> that can be constructed on a 50' x 100' lot) the engineered product with a
> base shear in seismic zone 4 equivalent to 0.133Wd compared to a wind load
> based upon a wind force of a 70 mph wind with Exposure C will require a
> greater number of holddowns and greater shear resistance at interior braced
> panels than those following Conventional Framing Provisions.
> The developer, however, advertises a full code compliant structure and
> falsely claims it to be equivalent to every other home in its size and price
> range.
> The public invests in these homes unaware of the cost potential down the
> road when the conditions are right and the home is subjected to a moderate
> or large earthquake or Tornado (or Hurricane).
> Legislation to provide a performance rating on homes would greatly help
> accomplish the following potential improvements. The advantages may not seem
> obvious at first but should include:
> 1) lowering the profit margin of the developer /owner by true comparison of
> the structural performance between competing structures. If the developer
> wishes to maximize profit at the expense of performance, the public who must
> burden the expense of repair has the right to know.
> 2) Disclosure may help improve the minimum standards for performance above
> the level of Conventional Framing by public demand. Personally, I believe
> that the home owner would choose to pay a 0.5% or 1.0% increase in
> construction cost to improve performance and reduce the personal liability
> when the event occurs.
> 3) Improved performance or disclosed rated performance may create an
> incentive for reductions in insurance rates. This is not possible today
> since the level of performance is unknown to the Insurance Carrier unless
> the home was constructed to some minimum level of compliance such as those
> required under a Fanny-Mae or HUD loan. Private lenders do not care what
> level of performance is followed so long as it complies with written code.
> 4) Advertised homes can use the level of performance as a marketing tool to
> promote sales. At this time the uninformed home buyer believes that all
> homes are built equal and that code compliance protects them from excessive
> damage as well as loss of life. This is why so many home owners are angered
> when they learn that a home performed as expected by code in spite of the
> level of structural damaged it suffered.
>
> Jay, this is a vastly debated topic. The SEAOC Listservice has 6,000
> subscribers world wide. We feel that the list is a growing voice which
> represents the needs of the vocal community. We feel that NAHB needs to
> encourage a partnership with engineers concerned with these issues.
> Membership affiliation is not enough when engineers have no idea who is
> carrying the ball in the code creation cycle. We also feel that there are
> many benefits to the Insurance industry which creates a strong allies with
> the home building associations, structural engineers and architects that can
> instill change for the benefit of the general public.
> Please don't misunderstand. Structural Engineers Association of California
> has taken a valiant effort to improve the provisions of the code, but many
> of us feel that they do not have sufficient voting power on the ICBO floor.
>
> The conventional framing section of the Uniform Building Code is incomplete
> and contains some serious deficiencies that the local building officials are
> powerless to enforce. In my town (La Quinta California) developers are known
> to place undo pressure upon the local city council with threats to move
> their development to another town unless the building official allows
> compliance to conventional framing based upon the developers interpretation
> of those missing or confusing sections of the code. For example, the section
> on interior braced wall panels fails to prescribe the connection of the wall
> to the structural diaphragm.
> ICBO has completed the last edition of the '97 UBC and will offer no
> revisions to this inadequate section - devoting their efforts on the
> creation of the IBC. The IBC, on the other hand, will not be adopted by
> local municipalities until approximately three years after it's initial
> publication or 2003 the earliest. So, for the next six years, the followers
> of the prescriptive method will be allowed to construct useless or
> ineffective shear connections of interior braced panels.
> These are only a few of the inadequate provisions of the code.
>
> I would be willing to devote time to HATDE with the understanding that we be
> allowed to post committee work on the SEAOC web or open the floor of
> discussion on the committee work to the engineers who subscribe to the SEAOC
> Listservice. This creates a channel for International engineers interested
> in having their opinions heard but how do not have the channel to do so.
>
> I urge you to enter into this discussion on our List and use our combined
> knowledge and experiences to help create a better prescriptive code for the
> non-professional to follow.
>
> I am active with both SEAOC and LGSEA (Light Gauge Steel Engineering
> Association - http://www.lgsea.com - which I believe NAHB is intimately
> familiar with.
>
> Please understand that are motivation is the protection of the public. We
> feel that the intent of the Conventional Framing section of the code is
> being used unethically to increase the builders profit at the expense of the
> welfare of the general public. SEAOC's Vision 2000 promotes a performance
> based code methodology. The difference is that the owner will have the
> control of performance. The general home-buying public is at the mercy of
> unscrupulous developers who use the provisions of Conventional Framing to
> line their pockets and the ignorance of the general public to cover up their
> actions.
>
> It is important that Structural Engineers have the lobby power to make
> constructive changes to the code for the benefit of the public. Your help in
> this matter is greatly appreciated.
> I have taken the liberty of forwarding a copy of this letter to the SEAOC
> Listservice so that the many engineers involved in this discussion will be
> aware of your awareness of our concerns and the possibility of our
> involvement in our list.
>
> I thank you in advance for your attention to this matter.
> Sincerely
> Dennis S. Wish PE
> La Quinta, California
> wish(--nospam--at)cwia.com
>
> ICQ# 6110557
> http://wwp.mirabilis.com/6110557
>
> "The greatest pleasure in life is doing what people say you cannot do."
> Walter Bagehot
>