You know you're interested in substitutions. Designers want to avoid them and contractors want to make them. But what's an option? You need to read the bidding documents and specifications carefully to understand exactly what is required and what is permitted in the particular contract you are working with.

"A substitution request is a proposal to use a manufacturer, product, material, or system different from one required in the contract documents," begins the chapter on substitutions in the Fundamentals and Formats module of the CSI Manual of Practice (MOP). An option is one of several manufacturers, products, materials, or systems, permitted for a particular purpose or location in the contract documents. And what are the rules for requesting substitutions? They vary from one contract to another.

The instructions to bidders should tell bidders whether or not the owner will consider substitutions, and a Section in Division 1, "Product Options and Substitutions," should describe the procedures to be followed.

The First Question Is When

It is typical to restrict substitution requests to a time during bidding, such as up to ten days before the bid date as is stipulated in the standard AIA Instructions to Bidders. Some owners, however, prefer to limit such proposals to after the bid, as in the standard language of EJCDC Guide to the Preparation of Instructions to Bidders. The standard or nonstandard documents used for bidding and contracting are selected by the owner, and it is typically the architect who prepares Division 1, so engineers preparing specifications or doing their part of contract administration must get this information from others on most of their contracts.

The Hottest Question: What is 'Or Equal?'

It can be difficult to determine what's "equal" to the specified product. Legally, in accordance with precedents and most contracts, the architect or engineer administering the contract makes the decision, but comparing products is not necessarily easy. If the specification that allows something "equal" to a named product also describes the product, the job can be easier.

In mechanical specifications, it often happens that one manufacturer of equipment routinely includes some feature that another manufacturer lists separately and charges extra for. If the description of the product used as the basis of design lists all the features that are required, it will make it clear to the bidder how to compare the costs from the two manufacturers.

Substitutions may reveal a superior or more cost-effective product than the designer was aware of during design. One reason why designers want to avoid substitutions is that it is time consuming and sometimes challenging to compare the proposed and specified items. It's better if the specifier has done enough research before preparing the specifications to have identified three or more products she or he considers equal, and names them. Then it's the contractor's option to choose which to bid.

Sometimes manufacturers publish tables comparing their product with others. These can be very helpful, but designers should be sure to discuss such comparisons with the representatives of all the products compared.

Designers should be aware of the time restrictions and procedures for substitutions in their contracts, and include in their estimate of the design and contract administration work the time that will be required to evaluate substitution requests.

And You Must Follow The Procedures

Standard General Conditions do not permit the contractor to introduce substitutions by simply including them in submittals without official written notice. The best contracts will include a form for substitution requests, typically attached to the Division 1 Section mentioned above. The MOP chapter includes a sample form and a checklist for evaluations, which can be equally valuable to a designer or to a contractor. The proposer is required to attach data describing characteristics sufficient for evaluation of the product, and a description of changes that will be required if the substitution should be accepted.

Substitutions can improve quality and reduce cost. However, procedures for proposing them are designed to maintain the fairness of the bidding procedure and to result in good record documents. Both users and preparers of specification must study the requirements applicable to the contract at hand.