It varies, but generally, construction specifications should include a detailed description of quality, workmanship, and standards, along with a clear benchmark for the completion of work. Construction specifications can evolve over the course of a project depending on factors such as cost, time, and availability of materials. That’s why having a flexible tool—like ProjectSight—to make the needed adjustments is key.

Drawings are visual representations of the project, while specifications are the written documents that accompany those drawings. For example, a drawing might show the location of multiple light fixtures in a space and have size and distance from the wall labeled. The project specifications, on the other hand, explain installation methods, what materials to use, and the expected power consumption of each unit. Drawings and specifications serve as the project’s primary working documents and are often used together to ensure work stays on track.

• Prescriptive specifications outline the needed materials for a project and provide step-by-step instructions on how to do the installation. For example, information about the size of a hole to cut to place a light fixture, along with the type of wiring to use, would be included in a prescriptive specification.

• Performance specifications leave installation details up to the subcontractor and simply document the predicted outcomes—such as the expected power consumption and heat output of a light fixture. If either of these is too high or low, the subcontractor will know something is wrong.
• Proprietary specifications are used when very specific materials and resources are needed—for example, when you’re trying to match new and existing materials during a building addition or renovation. If a light fixture needs to match the original gas lamp style in a historic building, those details would be included in a list of proprietary specifications.