A lot of people have never heard of construction specifications. Most know that buildings are constructed by builders who look at drawings to know what to build. However, not all the information that the contractor needs to know can fit on the drawings. That's where the specifications come into the picture.
Specifications are issued to the contractor along with the drawings for almost all commercial construction projects. They are the technical writing that goes with the drawings. Legally, the actual contract for construction is made up of not only the agreement (contract) between the owner and the contractor, but also the construction drawings and the construction specifications. The specifications complement the drawings, and expand upon the provisions in the agreement.
Everything that can't be communicated by a drawing goes into the specs.
Let's take ceramic tile in a bathroom as an example.
The set of drawings for construction will have a plan of the floor of the bathroom, and an elevation drawing showing what the entire wall of the bathroom will look like. The size of the tile will probably be shown to scale, and the height of the tile on the wall will be indicated and dimensioned. The extent of the tile on the floor will be shown. The drawings may have notes that spell out the size of the tile, and maybe the makeup of the substrate, and somewhere in the set of drawings, the actual manufacturer and tile product and color may be called out. There might even be large-scale detail drawings that show transitions between tile floors and other flooring. However, there's not enough room on the drawings to describe things such as the installation methods, codes and standards that the installation and products must meet, subfloor preparation products and methods, and mortar and grout types. Those go in the specifications.
Specific info that can be found in a tiling spec, which can easily fill 6 or more 8-1/2-by-11 pages, is as follows:
Requirements that the contractor submit to the architect information about the tile products before tile is ordered; the number of extra tiles required to be given to the owner after installation; specific requirements for proper delivery, storage and handling of tiles and grout and mortar before installation; project conditions, such as temperature in the room, before, during, and after installation; thickness of the tile; finish on the tile; backup, such as cement board; specific brands and products to be used for mortar and grout; patching compounds allowed to be used for repairing damaged floors; waterproofing membranes for use under the tile; tile cleaner products for use during installation; specific grout sealer products; methods for mixing mortar and grout; requirements for substrate conditions before tiling work begins; instructions on how to repair damaged substrates; methods for installing backup such as cement board; and specific procedures for tile installation, such as jointing pattern (an example from MasterSpec by AIA/Avitru/Deltek: “Lay tile in grid pattern unless otherwise indicated. Lay out tile work and center tile fields in both directions in each space or on each wall area. Lay out tile work to minimize the use of pieces that are less than half of a tile. Provide uniform joint widths unless otherwise indicated.”)
The specs are often issued in an 8-1/2-by-11 size booklet, and depending on the size of the construction project, this booklet can be 1 volume about 1 inch thick, or several volumes about 3 inches thick each.
Most people would rather look at drawings than read specs, but the specs are as essential as the drawings to the process of getting a project built according to the contract for construction.
Photo above by Liz O'Sullivan.
Beinecke Rare Book and Manuscript Library, Yale University, New Haven, Connecticut.