EnergyPlus uses Material
objects to define each opaque layer of construction material (brick, dry wall, etc.). You then use Construction
objects to define how material layers are combined to create assemblies (roofs, walls, floors, windows, etc.).
The EnergyPlus installation includes a data set file (C:\EnergyPlusV9-3-0\DataSets\ASHRAE_2005_HOF_Materials.idf for EnergyPlus v9.3) that contains common construction materials and their heat transfer properties defined in Chapters 25 and 30 of the ASHRAE Handbook of Fundamentals. These are already defined as Material
objects, so you can copy from this data set IDF and paste into your project IDF. This data set IDF also contains Construction
objects that represent common construction assemblies using these common construction materials.
You can read more details about material layer inputs in posts here and here.