Glossaries for blueprint symbols are available on The-House-Plans-Guide.com and The-Symbols.net. Hundreds of blueprint symbols are currently in use. There are no international governing bodies of these symbols; therefore, variations occur depending on geographical location, as of 2015.
Symbols are categorized by installation type such as landscape, HVAC, structural, electrical and architectural. Floor plan symbols are typically viewed in plan-view; that is, the planner is looking down on the structure with the roof removed. Door and window symbols fall into the architectural category and are often accompanied by a four-digit number that represents their width and height. Structural symbols indicate dimensions and sizing of the physical structure such as joists, concrete, footings, shafts and beams.