Architectural details are the drawings made at a larger scale than the plans and exterior elevations to accurately show the various methods of construction and the moldings and ornamentation on the building.
The scale of details varies according to the size of the item being drawn in detail. 1/2" = 1'- 0" and 3/4" = 1'- 0" are the most common scales used. When absolute accuracy is needed, like the intricate moldings on a decorative fire place mantel, full-size (life size) details are drawn. And the smaller scale details are usually included in the general drawings while full-size details are placed on their own separate drawing sheets.
The various types of details would be as follows:
Sectional Details - This is where we would draw something as if a knife had cut a slice out of the building plan and drew all the various parts of the construction like the studs showing all the things connected to them from the sheet-rock on the interior to the exterior sheathing and siding.
This type of detail would also show the insulation in the walls, floor, and ceiling, the types of rafters, end plates, headers over doors and windows, top and bottom plates of the walls, rafters or trusses, ceiling joists, and supporting structures, roof sheathing, shingle types, and ventilation, etc. These can either full cut away sections or partial depending on the detail needed.
Mill-Work Details - These details would show the angles of cuts and joints to various trims like base, corner, and wainscot moldings usually called chair moldings. This would also include special columns and railings.
Special Details - Items of special interest like kitchen and bathroom cabinet drawings or closet specialties like built in shoe boxes and clothing lockers.
Utility Details - Usually when a special fireplace, stair, book case or entertainment center is to be built, this would be done in section or elevation showing the various parts and the extra ordinary items.