After checking pre-sales and post-sales customer satisfaction of the company you will work with, you can focus on the following points:
Pay attention to the wall thicknesses. Find out whether weldless and bolted connections are made with connection details.
Make sure that the place where each profile will come from is clear.
Check whether exterior material is A1 class non-combustible material.
Analyse how wall heat details are. Pay attention to the presence of thermal bridges.
Make sure that manufacturer company has a corporate structure.