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Re: Housing Performance Objectives

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Despite the comments by Frank Lew, below, building codes that provide 
guidelines for design and construction of buildings with multiple 
levels of seismic protection and performance capability are here 
today and will continue to devbe developed in the future.

In the 2000 International Building Code, currently under development, 
one of the first steps in performing a design, is assignment of the 
building to a seismic design category.  The SDC is selected based on 
the desired performance characteristics of the building (per SEAOC's) 
Vision 2000 recommendations and the seismicity of the region in which 
it is located.  The code specifies minimum SDC's for certain 
occupancy classes.

The SDC controls the following:
1- permissible structural systems
2- height limits
3- detailing requirements
4- analysis procedures
5- quality assurance requirements
6- design force levels
7- permissible lateral drifts

Under the International Building Code, any Owner/Design team may 
elect to design for a higher SDC than specified by the Code.  
Interstingly, these SDCs are labeled A, B, C, D, E, and F (A being 
the lowest and F the highest).

By the way, a similar system has been in place in the BOCA National 
Building Code and SBCCI Southern Building Code for some time (4 or 5 
years)

Within the next 10 years, this Performance-based approach will 
develop further in the building codes.  Currently FEMA has engaged 
EERI to develop an action plan for a project, or series of projects, 
that will provide a basis for more reliable performance-based design 
of buildings.   This will likely result in an ATC-03- like 
document(s) that will then work its way into the building code.

I am afraid that building officials, despite their fears, will be 
stuck verifying designs to other than life safety.  However, they 
need not fear litigation any more than they currently do.  If their 
is a code available for these designs, they need only verify (as 
would the reasonable building official) that the design and 
construction meets the code - nothing more or less.  Similarly, 
engineers need only demonstrate the same. - not that the building 
actually performs as the code suggests.








> From:           FLew98 <FLew98(--nospam--at)aol.com>
> Date sent:      Mon, 8 Dec 1997 20:46:32 EST
> To:             seaoc(--nospam--at)seaoc.org
> Subject:        Re: Housing Performance Objectives
> Organization:   AOL (http://www.aol.com)
> Send reply to:  seaoc(--nospam--at)seaoc.org

> In a message dated 97-12-08 15:31:30 EST, Bruce Resnick write:
> 
> > Perhaps we could codify structures into A, B, and C levels.  
> 
> In a message dated 97-12-08 16:02:59 EST, Lew Midlam write:
> 
> > I doubt that you'll ever convince the code writers to incorporate anything
> in 
> > the code that is more than 'minimal requirements'.  Anything above and
> >beyond the minimum is something that is (and in my opinion should be)
> >between the designer and the owner.
> 
> Mr. Midlam accurately stated the mindset of most building offcials.  Plan
> checkers and Inspectors cannot perform 'clerk of the works'  functions for
> owners, which would be the situation if they had to enforce contractual
> agreements and specifications executed between owners and contractors that
> have no relationship with, or are above, the minimum life safety provisions in
> the codes.  The building official has a ministerial duty to issue a
> certificate of occupancy when those minimums have been met.  Would he/she hold
> up the final because the building, approved as an 'A', was more of a 'B' or
> 'C' in its as-built state due to field changes or workmanship? 
> 
> In our increasingly litigious society, building officials cannot risk (and
> most likely would be over-ruled by their city attorneys if they were foolish
> enough to propose it) being in the business of issuing 'good housekeeping'
> seals that 'guarantee' a level of seismic performance above the minimum.  When
> the inevitable suits are filed after the earthquake by owners who paid more
> for their 'earthquake-proof' houses that now have cosmetic cracks, the
> temptation to drag in the government will be overwhelming since it has the
> deepest pocket of all.
> 
> Frank Lew, SE
> Orinda, CA
> f(--nospam--at)lew.net
> 
> 
> Ronald O. Hamburger, SE
Regional Manager
EQE International, Inc.
San Francisco, California