March 14, 2023

What Does ‘Basis of Design’ Really Mean?

By Paul Daniels

A discussion this past week on Construction Specification Institute (CSI) – Connect caught my attention. It was between a group of architects and specification writers discussing the basis of design in a project specification and, more specifically, why you would include two or three alternative manufacturers in the spec. There were many opinions about what the architect was trying to accomplish using the term basis of design. Here are several of the comments:

“As I see it, the basis of design almost amounts to sole-sourcing, but with an almost-false veneer of ‘open proprietary specifying’ slapped on it to make it look good.”

“In my experience, the basis of design is meant for use with one product. Listing three products as basis of design is somewhat common but technically incorrect. If listing three products, the spec should instruct the reader to ‘provide one of the following…’”

“I don’t think listing more than one product makes sense?”

The other side argued:

“When using basis of design, to prevent a proprietary spec, the design professional must list three other manufacturers who can make similar products as the basis of design. Listing them in the spec allows for competitive bidding. Equivalent products by other manufacturers listed will be reviewed as ‘comparable products’ in regular submittals.”

“The whole point of listing something as a basis of design is to indicate that you used one product as the starting point for your calculations, measurements, color scheme, or assembly and that if the contractor chose to use one of the other listed products, that they are responsible for recalculating whatever the assembly is. If the products are functionally the same and ‘equivalent’ (not necessarily ‘equal’), then you have three acceptable products, not three products that are the basis of design.

“I would add, though, that for your specific situation … you need to see the Division 01 section that defines how a contractor is to submit an unnamed product in lieu of the basis of design product. That section is likely 01 60 00 ‘Product Requirements,’ but might be addressed wherever submittals are addressed instead.”

Each of the participants did not dispute the last opinion. When a general or subcontractor is bidding on a job, no matter how the specification is written, you will find instructions in Division 01 of the specifications under “Product Requirements” on the correct way to submit your preferred manufacturer. Whether it is the basis of design, an or-equal, or a substitution, as long as you submit the product correctly as spelled out under “Product Requirements,” your bid should be considered.

Many manufacturers will help you submit their products on a bid correctly. Just because you see a manufacturer called out on the spec as basis of design, don’t feel the need only to bid on that product. In today’s market, value engineering, condensing lead times or reducing costs can win you the job and keep it profitable.