Free hand drawings are easy to make. It can be made using a small piece of paper or can be made using a computer. Many architects and engineers are well trained to express there ideas intently using free hand sketch. Many computer programs are available for free hand sketching.
There are various types of technical drawings like 3d drawings (isometric, perspective), exploded 3d view, working drawings, detail drawings, schematic drawings etc. All these types of drawings are made at different stages of construction, showing different level of details.
Civil engineering drawings such as excavation drawings, form work drawings, road layout and utility drawings are extremely important for civil engineers to execute project. Special structures like bridges, chimneys, roads have highly complex drawings for execution.
Red line drawings are change markups made on construction drawings showing actual on site conditions.
BIM can help change management during construction. Every instructions for on site change from the construction drawing set could be recorded and analyzed using BIM. BIM 360 Field is an cloud based application where all scan data to field changes could be managed. Field and design office comes on same platform using BIM.