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RE: Two conditions in residential construction

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Steven,

You asked me a loaded question. You have described the Conventional
Construction provisions of the Uniform Building Code and the conditions
in which homes are allowed to be constructed without conforming to
full-compliance provisions using either an architect or engineer. As
long as these guidelines are met and the other provisions of the code
that need to be tested (geometric irregularity, shear path discontinuity
etc.) then there is no argument that the builder has the legal right to
construct the home - even in seismic zone 4 - to these provisions.

But there are issues which the law can not cover. Individual greed or
misuse of the law is not illegal and the law has not business
interpreting the intentions of the builder. However, this should not
allow the public to be taken advantaged of and sold a product without
disclosing the expected differences in performance separate Prescriptive
construction from Full-compliance engineering.

Furthermore, a law should not be so full of loopholes as to invite abuse
that prevents the public from taking measures to protect the largest
investment they will ever make.

Ignorance:

The building department, building industry associations, architectural
and engineering organizations do nothing to educate the public as to the
differences in performance expected of homes built to Prescriptive or
full-compliance methods. A building permit, in the eyes of the public,
validates construction and implies that the performance expectation of
each home is comparable. In truth, we know this is not factual - adding
mechanical connectors, plywood, straps or evaluating the load path of
the shear transferred through horizontal and vertical diaphragms will
result in difference level of performance - more or less damage. 

The law does not require the homeowner to be made aware of this fact and
allows the builder to make advertising claims that stretch the truth and
fortify the claims of equality.

Workmanship:

The code that requires compliance to prescriptive measures implies that
the builder (framer or owner-builder) has read and understand the
provisions. I have yet to meet a framer or General Contractor who has
read this section of the code or who has the ability to interpret the
code rhetoric? The legal wording is even more difficult for a layperson.
Some building departments invest in writing a graphical interpretation
such as the City of Los Angeles Type V sheet. 
I contend that while the code provides a prescriptive method it does
little to enforce the ability of the owner or builder to understand the
provisions. Furthermore, if you design a method of construction
intending to reduce the degree of protection that is placed in a
building, the building official should be responsible to take additional
precautions to ensure that there is adequate compliance during
construction. I have not seen this occur in my area where the majority
of homes are constructed by prescriptive standards (check out the
Structuralist Hall of Shame for examples).

I don't think it is too much to ask that if  you allow a less
restrictive construction method to replace an engineered solution that
you require a greater degree of skill by the person assembling the
system than you would in a more conservative design.

The line of distinction:

The biggest complaint that I have stems from what has historically been
allowed in building codes. When a professional engineer or architect is
not used, the provisions are generally more restrictive rather than
less. If you allow Prescriptive Construction then the baseline for
compliance should be the same as the minimum level resulting from
full-compliance to the code. This should be especially true in regions
of high risk.

Allowances:
Finally, it comes down to who is building to lesser standards. In my
opinion, if the owner of the home who intends to live in it rather than
sell it as an investment should be allowed to determine the level of
performance with Prescriptive construction offering the least
protection. Conversely, the Insurance companies should be allowed to
charge rates that are based on the historic performance of building
designed to either prescriptive methods or to full-compliance. 
Construction defects should not be excluded from claims because the
damage has resulting from inadequate workmanship or non-compliance to
detailing has not occurred at the time the claim was filed. Codes are
intended to mitigate hazards and this is an anticipation of damage based
on historic recorded performance of homes with defective workmanship.
For those who have not heard - Aas vs. William Lyon's was upheld by the
California Supreme court last December (2000) in favor of the Contractor
as the courts claimed the defect in workmanship and non-compliance to
code had not resulted in damage or injury and therefore could not be
claimed against the developer. This ruling denigrated the intent of the
code to prevent major structural damage or loss of life. I understand
that new legislation was in the works to overturn or compensate for this
ruling, but until it is done, the homeowner is at the greatest liability
because they must disclose the code deficiencies but have no claim
against the builder.

Bottom Line,

The solution is to disallow prescriptive methods in high risk zones
unless chosen by the owner who intends to live in the house for at least
a long enough period of time as to show that the home was not
constructed to sell. In this case, the method of construction should
become part of public record (disclosure) and the Insurance company and
mortgage lender should be able to set fees (insurance premiums or
mortgage interest) based on the anticipated level of damage judged from
historic performance records (such as the Northridge earthquake). Homes
which are retrofit with mechanical connectors should be rewarded by a
reduction in premiums. 

The minimum level of prescriptive design should be equal to or greater
than the minimum level of a fully compliance engineered solution.

Structural systems of a residence should not be constructed by an
inexperienced owner or builder. It should only be intrusted to a framer
who is certified by education and on-site testing of his or her ability
to perform the work and to interpret the code.

It is my understanding the NAHB has started Framer Certification
programs and some of the large builders are participating. My concern is
that to the best of my knowledge, large developments are not
prescriptively constructed by designed by Architects or Engineers. The
Conventional or Prescriptive portion of the code occurs in projects that
were originally intended to be Owner/builder projects but have been
allowed for builders or developers of less than 10 homes per year (such
as exists in areas such as mine where over 90% of the 3000 homes
constructed in our neighborhood are designed and constructed by
prescriptive means.

Certification must be required of builders in the private sector who are
constructing small projects rather than large tracts. This will
discourage anyone who can swing a hammer from taking the title of Framer
and being entrusted to construct a load path without the close scrutiny
of a well trained building inspector (the only source of field
inspection).

Finally, the method and expected performance level of prescriptively
built homes must become public record and disclosed to the homebuyer.
This is the only way for the homebuyer to drive the market and demand
better quality. Until this happens, the public will remain in the dark
about the differences in construction quality (unless they log on to the
Structuralist.Net website).

Since it was a loaded question, it deserved a fully loaded answer. Sorry
to be so verbose - but most of you expect it of me!

Dennis S. Wish, PE
California Professional Engineer
Administrator - The Structuralist.Net
Website: 
http://www.structuralist.net
 


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