The Joy of Specs

When you ask for a sandwich at the deli, it may sound like “Can I have a ham and swiss with mustard on a roll?” probably not ” Can I have a sandwich?”

traco-pics-009 window? what kind?

You are specifying the ingredients for the sandwich in the 1st example and get a result that you are more likely better if you put some thought into your request.

This is just an analogy for the way we describe the components of a building. This is why we have specifications that accompany the drawings to help inform the builder about the products that should be used in the construction of the building or site.window-1227796_1280

When we say the wall is framed with wood 2 x 4’s, if the type of wood is not indicated, if the strength of the wood is not shown, if the species of wood is absent, if the moisture content is missing, – you will usually get the cheapest¬† available wood which will be of lesser quality than a properly specified lumber.

There are several ways to specify items for construction:

Performance Specifications address the operational requirements of an installation. The focus is on the project outcome, indicating how the final installed project must be able to function. Here, architects provide direction to the general contractor about what is needed and the general contractor must determine the best path to achieve the desired outcome. While this approach gives the general contractor flexibility in his construction approach, it limits how much authority an architect maintains once construction is underway.

Prescriptive Specifications contain detailed descriptions of what specific materials must be used as well as the installation instructions. This type of spec usually involves three key components:

  1. General provisions: requirements surrounding codes and standards
  2. Required products: the type of products required based on performance and structural stipulations
  3. Execution procedures: how to do the install and measure its effectiveness

Prescriptive specs put a greater burden on the architect (as opposed to the general contractor) to ensure proper installation.

Proprietary Specifications demand that only one specific product be used for a given installation. It commonly utilized if the portion of a project requires a certain performance that only one product can achieve. This could ultimately drive up project costs.

It is critical for building/design product manufacturers to understand the various types of specification as well as in which spec scenarios their products will most frequently be considered.

These specs can be in the drawings as pages of text or in book format but should relate to the actual project, not just a generic spec that is a boiler plate.


We aim to keep our specs accurate, but still allow a certain degree of flexibility in order to allow the contractor some choice in ordering products to create the project.