What is the substrate? If wood or light gage steel, most codes in the US require a 3-coat stucco system. Proprietary one-coat systems can be locally approved by the building official, provided certain information is provided (ICC Evaluation Report for instance). EIFS can also be approved, but again, should be done as a clear variance to the code-required system
If you are putting stucco on concrete masonry or on concrete, it is required to be at least a 2-coat system.
The details for stucco are important. Since I don't know what code you're dealing with, I'll cite the International Building Code, Chapter 14 "Exterior Walls". Let's assume a wood frame with OSB or similar substrate. For this you will need two layers of a water-resistive barrier (WRB). No. 15 felt is preferred, but a combination of felt and house wrap is acceptable. The WRB must be tied to the window or other penetration flashings so that water is directed to the exterior, not to the substrate or behind the WRB. A weep screed is required at the bottom.
Standard details for stucco are almost non-existent. There is a group in the western US called the Northeast Wall and Ceiling Bureau. They have some details, but they are pretty bad and I wouldn't use them.
The PCA Stucco Manual is good for a general reference. The ICC and most of its derivative codes also reference ASTM C926 and ASTM C1063 which are required for code compliance.
Attached is one of my standard weep screed details. I have others if you let me know what you need.
