Abstract: The layout tool is used for marking the positions for building materials, such as studs, joists, rafters, trusses and rough door opening trimmer studs, before nailing in permanent position on wall plates and sill plates. The layout tool has templates that are the same width of building materials, that are attached at indicia markings, "on center", from either end of an extruded member and the interlocking design of the manufacture keeps them perpendicular. Also provided are the rough door sizes that are indicia marked and layout can be marked from either end of invention.