The method of describing design intent and furnishings.

Further Reading

Lisa Godsey, Interior Design Materials and Specifications (Fairchild Books, 2017).

Specifications are written documents that detail all the elements and expected levels of craft and published standards of a project. They contain textual descriptions of all elements of a project—such as finish types, lighting, substrates, and furniture. They are used (alongside design drawings, schedules, and design details) to solicit competitive bids from contractors and suppliers.

There are two categories of specification documents open and closed, which are sometimes referred to as “prescriptive” or “proprietary.” Open (prescriptive) specifications are developed around performance, and allow for substitutions and competitive bids. Closed (proprietary) specifications are for elements that must be in a project, which names a specific element (such as a piece of furniture from a single manufacturer) and limits acceptable substitutions. Each specification category is connected to the type of project; for instance, commercial projects are best served by open specification because they are more general in scope with more flexibility for acceptable substitutes and options. The more specific a project (such as a high-end retail space with corporate standards, or a residential project with a client who requires exact finishes for a finished product) requires a closed spec.

In addition, the language and syntax contained within specification documents are highly formalized. In North America, two formats dominate MasterSpec and MasterFormat. There are specialized consultants and softwares that are used for specification writing, so the type of project should be taken into consideration before deciding on which specifications are appropriate.