| Author |
Message |
Tracy Van Niel, FCSI, CCS
Senior Member
Username: tracy_van_niel
Post Number: 321
Registered: 04-2002
| | Posted on Tuesday, October 25, 2011 - 10:18 am: |    |
I'm working on a section with some criteria that the project architects think is important to include as a performance requirement, but I'm thinking it would be better placed as a design requirement. I know what the 'old' MOP says about the two but just curious how everyone else in the real world determines what goes into design requirements versus performance requirements.
Tracy L. Van Niel, FCSI, CCS |
anon (Unregistered Guest)
Unregistered guest
| | Posted on Tuesday, October 25, 2011 - 02:06 pm: | |
What do you mean by "better placed as a design requirement?" Placed in the Contract Documents? If so, then performance criteria has to be included as an integral part of this ("delegated design").
Or do you mean that you think the Architect should be desinging whatever it is you are referring to?
Delegate design - transferring design responsibility of portions of the work to the Contractor - REQUIRES the Architect/Engineer to provide ALL of the necessary performance criteria so that the Contractor can design these portions of the work. See AIA A201 3.12.10 for the exact language... |
Tracy Van Niel, FCSI, CCS
Senior Member
Username: tracy_van_niel
Post Number: 322
Registered: 04-2002
| | Posted on Tuesday, October 25, 2011 - 03:01 pm: | |
No, anon. It's not delegating design responsibility. But the requirements are not test methods which to me means not included as a performance requirement.
All I was asking for was the opinion of other spec writers as to what types of items they place in design requirements versus performance requirements. I wasn't asking for a smart alec reply ... I get enough of that at home from my teenage son.
Tracy L. Van Niel, FCSI, CCS |
Steven Bruneel, AIA, CSI-CDT, LEED-AP
Senior Member
Username: redseca2
Post Number: 300
Registered: 12-2006
| | Posted on Tuesday, October 25, 2011 - 05:16 pm: | |
To use curtain wall as an example:
Performance requirements are those criteria that can be verified through testing, including: Structural related concerns like seismic, wind load, deflection and so on; Energy related concerns like insulation value, glazing performance criteria and so on; and Building envelope related concerns like water air and penetration.
Design requirements I think of as the visual requirements of the approved design, including: Framing member profile, Gross layout and spacing, Color/type of glass within energy performance parameters and metal finish. For critical designs you may also require tightened tolerances for fabrication and erection beyond the standard. |
J. Peter Jordan (Unregistered Guest)
Unregistered guest
| | Posted on Wednesday, October 26, 2011 - 09:46 am: | |
In my experience, when people request a "performance" specification, they actually mean a non-proprietary specification. In many cases, specifying performance is somewhat irrelevant. |
anon (Unregistered Guest)
Unregistered guest
| | Posted on Thursday, October 27, 2011 - 01:02 pm: | |
I am still not understanding the distinction between "design" requirements and performance requirements, and was not attempting to be smart alecky.
The only reference to "design requirements" I can find in the current CSI SectionFormat has to do with Sustainable Design submittals and closeout documents. The previous version did indeed include a Design Requirements heading under the System Description Article heading, but no definition of what is meant by "design requirements" is included in the document. Instead, "design requirements" and "performance requirements" are used interchangeably and appear synonymous.
In the Project Resource Manual, "design requirements" seems to be synonymous with performance requirements as well. In the performance specification example provided, under an article heading "Performance" the PRM eschews use of the term "design requirements" and instead states:
"The added article “Performance” is
used specifically to describe the design
requirements and desired performance.
This is accomplished by listing the performance
attributes of the system. For
each attribute, the A/E must select
applicable requirements stating discrete
needs or expected results. These
requirements must be limited by criteria statements that set limits or give standards."
So, Tracy, if you can respond without being such a crank, I would be interested in knowing if there is some distinction between the two terms that I am missing. I just don't see it.
thanks |
J. Peter Jordan (Unregistered Guest)
Unregistered guest
| | Posted on Friday, October 28, 2011 - 10:01 am: | |
Design requirements would also include requirements that are related to visual characteristics (arrangement of forms, color, pattern, gloss), programatic requirements, and general performance standards from which performance requirements are derived. A design requirement would be to select products and systems that meet code-required fire separation requirements; the performance requirement would be to select products/assemblies that have been tested and labeled by UL to meet the fire-resistance requirements identified in the design.
Design requirements may also be related to project or budget; this is not usually considered to be a performance requirement written into the specifications. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 426
Registered: 10-2007
| | Posted on Friday, October 28, 2011 - 12:29 pm: | |
As a minimum we have established that the distinction between Design and Performance requirements is not clear. When I hear "design requirement" I think about design criteria.
Personally I like to think that design requirements should be objective but the examples of Design requirements emphasize the subjective elements. |
Lynn Javoroski FCSI CCS LEED® AP SCIP Affiliate
Senior Member
Username: lynn_javoroski
Post Number: 1331
Registered: 07-2002
| | Posted on Friday, October 28, 2011 - 12:59 pm: | |
I agree with Peter. Performance Requirements, in my mind, are a sub-set of Design Requirements. So the Design Requirement might be brick, but the Performance Requirements would address the specific qualities of the brick for grade or type, etc. |
Steven Bruneel, AIA, CSI-CDT, LEED-AP
Senior Member
Username: redseca2
Post Number: 301
Registered: 12-2006
| | Posted on Friday, October 28, 2011 - 03:10 pm: | |
The most common "design requirement": Match Architect's sample.
I tend to agree with Mark, the "design requirements" are the usually subjective qualities that define a 'design" versus those we call performance requirements because they can be verified by recognized testing procedures. |
Gerard Sanchis
Senior Member
Username: gerard_sanchis
Post Number: 55
Registered: 10-2009
| | Posted on Sunday, October 30, 2011 - 08:06 am: | |
If we can't agree amongst ourselves, think of the readers of our documents. They're probably making up their own definitions of the two terms.
These fine points of discussions always remind me of the controversies between medieval scholars about the number of angels that could fit on the head of a pin. For those with time to spare on a Sunday morning, "Quantum Gravity Treatment of the Angel Density Problem" by Anders Sandberg will rival this thread.
I think that the next MOP (or whatever it's called these days) needs to define both terms. |
J. Peter Jordan (Unregistered Guest)
Unregistered guest
| | Posted on Sunday, October 30, 2011 - 11:55 am: | |
There are a number of terms that architects throw around, the definitions for which there is a distinct lack of concensus. Two have to do with design phases, schematic design and design development. This fuzziness can cause critical problems when there is a lack of communication. It services many architects well to avoid clear definition, but it causes problems when clients expect 50% CDs at the end of schematic design. Where do you turn (what standard of practice exists) for assistance it telling a client that what they expect is unreasonable. On the other hand, there are those architects who get well into generating construction documents before they present to a client an elevation of the building (yes this did happen on one of my projects).
The architectural profession has a long-standing attitude to tolerate (or even encourage) a wide variety of approaches to design practice (as well as eduction-but that's a different rant). This does not, in my view serve the professional well in the long run. Other stakeholders in the building procurement process are stepping in(actually have stepped in) to provide their own definitions.
When we don't understand the difference between design requirements and performance requirements, how can our clients expect us to know what schematic design is so they feel that it is up to them to make it up. |
Robert W. Johnson
Senior Member
Username: robert_w_johnson
Post Number: 169
Registered: 03-2009
| | Posted on Sunday, October 30, 2011 - 01:39 pm: | |
The 1997 edition of the SectionFormat included SYSTEM DESCRIPTION in PART 1 with Design Requirements, Performance Requirement below it. Definitions of the two terms were not included.
The 2008 edition of the SectionFormat deleted those items from PART 1 and added PERFORMANCE/DESIGN CRITERIA to PART 2 with some definitions:
"PERFORMANCE/DESIGN CRITERIA
Include performance-related characteristics of products. Types include structural, safety, fire resistance and retardancy, acoustical, thermal, operational capacity, and durability. Performance should be capable of being verified by observations or tests and stated as: (1) a property name; (2) a value and units of measure, if applicable; and (3) a method of evaluating or verifying performance, such as a test method.
Performance characteristics may apply to systems, assemblies, components, and materials. The term "Design Criteria" is used when describing the intended characteristics of a product for which the Contractor is assigned design responsibility.
Include appropriate methods of substantiating performance characteristics in other locations in the section. ............."
These two definitions are in general agreement with a majority of the discussion above.
David Lorenzini may want to expand on the change in terms and location. I did not agree with the movement of the subject from PART 1 to PART 2 since many performance requirements deal with installed products or systems and not just products. The task team obviously did not agree with my voiced opinion.
History of MOP/PRM/Practice Guides: The Manual of Practice (1967 - 1996) went through several expansions and revisions. The Project Resource Manual was published in 2005 to replace the MOP. The Practice Guides are in the process of the replacing the PRM with the first three published in 2011 as noted by Helaine in another thread. The information is going back to a divided modular organization to make it easier on those taking the certificate/certification exms. |
|
4specs.com Home Page