Basis-of-Design

Archive of Older Topics Archive - Specifications Discussions #6
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There have been more than a few instances where I have seen the Basis-of-Design specifying method clearly and poorly implemented. In order to provide clarification and guidance, I drafted the following. Am seeking any additional input and comment.

Manufacturers/Products - General
Specify all salient performance/design criteria/characteristics to establish minimum requirements.
One or two manufacturers/products are acceptable.
Three or more manufacturers/products is preferable.
However, if naming a single manufacturer, one must:

  • Include, the words Or approved equal. [kh: public entity]
  • Or, specify using a Basis of Design method (see below for accompanying guidelines).
    Otherwise, eliminate the term basis-of-design if not using a true basis-of-design.

Basis-of-Design
Definition from MasterSpec

  • This specification method consists of both naming a single product and several additional manufacturers. The named product establishes the salient features against which comparable products of the several manufacturers listed may be evaluated. Qualities may include type, function, dimension, in-service performance, physical properties, appearance, and other characteristics.
    Reason for use
  • The basis-of-design method is becoming increasingly prevalent because of time pressures on the Architect. It avoids some of the time-consuming procedures involved with the evaluation of products during design.
    Guidelines on Use – one or more of the following:
  • Drawn conditions cannot be generically presented without depicting a specifically named system or product.
  • Specific aesthetic quality required (e.g. specific manufacturers color/texture/etc.) that cannot be specified using another manufacturers standard available options.
  • The Architect does not have the time to fully evaluate and compare multiple products but will consider comparable products, provided they meet the significant qualities of the product specified. [kh: not ideal]
    Example Applications:
  • Elevators
  • Escalators
  • Curtain wall
  • Architectural product aesthetic (e.g., Tiling finish)
    Suggested wording from MasterSpec (add Division 01 section, Product Requirements):
  • Basis-of-Design Product: Where Specifications name a product, or refer to a product named on the Drawings, and include a list of manufacturers, provide the specified product or a comparable product by one of the other named manufacturers. Drawings and Specifications indicate sizes, profiles, dimensions, and other characteristics that are based on the product named.
    Cautions
  • Although it avoids some of the time-consuming procedures involved with the evaluation of products during design, evaluations of proposed comparable products can consume the Architect’s time during construction.
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Some of my clients use basis-of-design without identifying other manufacturers. For that reason, I have augmented the definition in Section 016000 w/ the following subparagraph:

“Where Specifications name a basis-of-design product, or refer to a basis-of-design product indicated on Drawings, and other products or manufacturers are not listed, provide the specified or indicated product or an approved comparable product. Comply with requirements in “Comparable Products” Article for consideration of a product by another manufacturer.”

I avoid using undefined terms like “or equal” unless explicitly req’d by the owner, and prefer to use “or a comparable product” or “an approved comparable product.”

3

Division 01 is commonly written so that the process for comparable product requests may allow some less scrutiny than that of substitution requests. Under a basis of design spec, the wannabe submissions go through as comparable products. so I think the ideal use for basis of design is, as is commonly defined, with a list of vetted other manufacturers, to indicate those more likely to comply. If there is no list of other manufacturers or they have not been vetted, it may be better to specify using the manufacturers paragraph with the option for available but not limited to the following, rather than the basis of design paragraph. I suspect as much as nine times out of ten this is really what architects mean when they say basis of design, especially if they have never read division 01.

Also keep in mind that postponing the review of competing manufacturer’s products simply invites more work to have to do later when unqualified products come through and you have to prove they’re unqualified with only a squishy spec to stand on. I do find some interesting merit to Jeff’s approach at least it recognizes what the architects are really saying and puts that in writing in division 01. I tend to take a purist’s approach but it’s a constant challenge. A worthwhile one I think though, except for those cases when the architect says “I really just want to call it the basis of design anyway”.

Konrad, I hope this helps answer your inquiry. I don’t know the application for which you are using this if it is perhaps training resources for others, if so this is a very worthy topic.

4

also emphasize the importance of specifying the salient attributes

5

I work for a “public entity” and have to keep my specifications compliant with procurement legislation. I have used a B.O.D. paragraph similar to yours which has passed muster with the legislative requirement to specify “or equal”

A. Basis-of-Design: Subject to compliance with requirements, provide (name of product) by (name of manufacturer), other available manufacturers offering acceptable equivalent products that may be incorporated into the Work include, but are not limited to, the following:

  1. (insert manufacturer and product).
  2. (insert manufacturer and product).
  3. (insert manufacturer and product).
  4. Manufacturer and product approved by the
    Design Professional as being an acceptable
    equivalent.

Not perfect, but it works with the legislation we have to work within. It would be nice if this type of legislation was authored by Architects and Engineers, but most are Lawyers.

6

Thanks, Jeff and Chris, for your comments.

Chris, it seems to me that the manufacturers method of specifying has its place. However, for instances where the drawings have to truly reflect a “basis of design” – where the details or dimensions are drawn specific to the named manufacturer, and cannot be drawn generically (e.g., elevators, curtain walls), I see BOD as appropriate. I feel it is important to let the Contractor know that the design is based on THAT system/product, and that any substitution may result in additional re-design costs (which they should bear).

You say, “…with a list of vetted other manufacturers,”, but then you also say, “…more likely to comply.” Do you think they should be completely vetted?

On a related note, if naming other multiple acceptable manufacturers, do you see listing the salient characteristics as the minimums each manufacturer must meet? Or, are they simply characteristics of the named manufacturer?

I ask this because…what about those instances where a specific aesthetic is desired? A certain labeled-finish of the listed “basis” product can be named, but it cannot be applied as an exact feature to any other product. So should other performance criteria be held in similar light?

Put it alternatively this way…given that a curtain wall system has certain details and “specs” that dictate a certain product, should listing salient characteristics exclude those features that are specific to a single manufacturer? Or, should they be ‘minimums’ and generic? If generic, I have seen specs list member profile dimensions in the curtain wall section (yes, this should be on the drawings, but disregarding that…) is listing the exact dimensions or listing minimum sizes/thicknesses that the other listed manufacturers should also meet preferable?

Hope this makes sense.

7

Thanks, Richard. I did not refresh my browser to know that you responded before I did. How do you handle the questions I posed above?

8

Do you think [manufacturers] should be completely vetted?< How much time and fee do you have?

Salient characteristics apply to products, not manufacturers. They should apply equally to the applicable products of each listed manufacturer. Listing as “salient” those characteristics that the architect knows only one manufacturer can meet, is playing games and will end in disputes.

9

Dave, maybe “completely” was too extreme a word. Chris, I’ll give that “most likely” is understandable (Sorry, if I came across as antagonistic, just seeking clarification. Newer to posting, I’m not used to how the written word without nonverbal nuance, can come across). I was just testing the amount of due diligence that should be exercised before listing similar systems/products.

If weakly vetted, how much “design work” should be left up to the Contractor? (Otherwise, there’s always the delegated design method… :slight_smile:

10

Sometimes the basis-of-design selections you make are based on criteria that are opaque to the bidder or the manufacturer, they wouldn’t never think of it unless you state it clearly.

An example I recall is a project where the critical basis-of-design criteria for a roof mounted cooling tower was the height of the unit. The building design was maxed out to the allowable height limit. We would gladly adapt to any format if they kept below a maximum of 10 feet or so maximum height above the top of roof steel.

11

Konrad, my intention was for minimum/maximum/tolerance as applicable. Time & fee are likely the problem, as Dave pointed out, and probably also too many people who were raised thinking BoD means you can pick and choose during CA what you will enforce. A careful reading of 016000 and 012500 would be worth the time to anyone who would like to understand the real intent.

Great observation Steven makes too, an example of why every project stands on its own when it comes to getting into a spec. A salient attribute for one project may not matter at all on another project. To apply this to Konrad’s question about min/max vs spec exactly the BoD: OK, 10 feet is Steven’s maximum for this project. If the first product someone found on 4Specs is 8.5 feet, should you write the spec for it to be exactly 8.5 feet high? If so, there might be 5 or 10 other capable manufacturers whose products are up to 9.75’ high but would be knocked out of the bidding, when they could have otherwise done a fine job for less cost. If you can determine that 10 feet is the maximum, say not greater than 10 feet.

Possibly the worst thing would be to say Acme cooling tower product xyz is Basis-of-Design, period, end of story. Same effect as saying “or equal” end of story. You haven’t bothered to tell them about the 10 feet height limit? Or perhaps that it this is one of only a handful of manufacturers who have it in Type 316 stainless steel, or whatever you must must have. Then you are welcoming requests to be considered for the project from everybody who makes a cooling tower, eating up gobs of everybody’s time and making people look silly.

Some sophisticated owners and agencies require that truly competitive specs are written. This is great if well implemented and if they consistently enforce it, because it moves design fees toward where there is time for selecting multiple product options and for the specifier to spell out the requirements more fully, so more value may find its way into the built project. Well, if the opportunity is still there after a series of obstacles from others along the way before the spec writer is involved, and if any cost savings are not undone by the owner themselves and myriad other reasons.

What if though, just what if, the specifier could serve as Project Information Manager, as proposed by Beth Stroshane and Marc Chavez’s “Evolve the Specifier” presentation at CONSTRUCT 2014? I would venture to say, there would be far greater possibilities for truly researching and fully specifying the right range of products, doing a coordinated VE effort as a part of design before it becomes disruptive, and integrating the correct terminology and level of detail in the model. The reason I bring that up here is that then there would not be the types of obstacles we have today where even if there was fee intended for the research, it’s gone or too diminished by the time designers would be selecting products, let alone selecting additional products and establishing the project’s real criteria.

As a brief summary, perhaps there could be ways to integrate one or more of those ideas into your process –

  1. Require salient attributes to be stated as min/max/range as applicable and that all listed mfrs can comply

  2. Require 3+ mfrs or special approval and police that diligently if you want real value, only giving approval for truly valid exceptions - state in your requirements what are the valid exceptions and how others might be decided

  3. Require that the usage of BoD terminology be coordinated with Division 01, make references in editor notes.

  4. Set requirements for the personnel who will be writing specs e.g. CCS + minimum field experience, and not a stranger to BIM might be a plus.

5.? Consider hiring a specifier directly as a consultant to the project, at least that is the idea that was presented. I wonder how this works for the designer of record to review, sign & seal specs that were not by someone they hired? Subject for another thread.

Just ideas since you were having trouble getting consistent results.

12

(Too busy to respond sooner) Thank you very much, for your detailed response. Great thoughts – you and Steven provided precisely the considerations and perspectives I was looking for.

Chris, I found your original post also very helpful (since replaced by your 2/27, 1:37 pm post), and am not sure why you removed it, as it had many other good points that seemed worthy to carry over – tight fee scenarios; multiple, pre-selected products; hidden sub cost factors. To continue,

Requirements: In regards to maximums/minimums, I am wondering how and where to best distinguish if requirements are for just for the named product, or for any proposed products? Specific language examples anyone?

Aesthetics: If maximum/minimum requirements apply to all (above), aesthetic requirements obviously apply to only the BoD product, since quantifying or defining a generic descriptor of certain color/texture/finishes can be difficult. Yes, the Architect has the final judgment call, but does anyone have an example of a conflict on a proposed similar aesthetic that was hotly challenged?

13

Regarding aesthetic criteria, I would probably use wording something like the following:

“Products of other manufacturers that meet the specified requirements, and are sufficiently equivalent (i.e., close enough) to the Basis of Design in aesthetic appearance (design, configuration, color, pattern, texture, sheen, etc.) to satisfy the design intent of the Architect, may be submitted for consideration as substitution requests in accordance with Section 01 25 00 Substitution Procedures. The Architect will be the sole judge of aesthetic equivalence.”

(Would this work? If so, could it be improved?)

14

Keep in mind these days that we’re often asking for life cycle costing as part of the substitution criteria; or we’re asking for a product with very specific documentation (cradle to cradle or something else like it); or it has to meet a distance requirement (LEED v4 is 100 miles); or it has to coordinate with existing systems. Less and less am I looking for criteria of the actual material, and more frequently I’m looking for this type of peripheral sorting. By “peripheral”, I mean criteria that have nothing to do with how the material actually performs but how it fits sustainability criteria.

if a comparable product meets all that, then we take a look at the aesthetic properties.

15

On highly aesthetic items, if it is public bid, BoD might not be a good method in some cases. There is probably not a good way other than preselecting and specifying multiple products.

2.x Widgets: Generic brief description of widgets, complying with ASTM X999 Category Y Type Z.

A. Products: Provide one of the following:

  1. Mfr A; Product 1. (The interior designer wants to stop right here)
  2. Mfr B; Product 2.
  3. Mfr C; Product 3.

B. VOC Content:

C. Regional Materials:

D. Performance Requirements:

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As you note, interior designer wants to stop at item 1. Because evaluation by this group typically ends at what it looks like, it’s likely nothing else will be accepted. Given that reality, there’s little point in specifying B, C, D, etc. Except, of course, to make it look like options are being considered. Interiors people would like to do everything as “No substitutions.” That certainly would make our job easier! Public sector bidding is a joke.

17

Statutes be damned, along with saving taxpayer dollars, so a designer can go home and leave someone else grueling til late to attempt to keep their mess from blowing up on them. But if we allow products they later don’t like, it is a no-win situation for everyone.