The Building Code of North Rhine-Westphalia is the legal foundation for the activities of the building supervisory authorities. It includes regulations for the development of properties and for structural facilities such as stability, fire protection, and thermal insulation. Its core consists of the regulations regarding the building supervisory procedure, such as the building application, the preliminary decision, and the building permit. The new commentary on the Building Code of North Rhine-Westphalia offers a concise, practical explanation of the code. The collaboration between legal experts and technicians ensures a balanced commentary. All questions relevant to safe planning and construction execution are addressed. The focus is on practical issues such as distance areas, structural facilities, the powers of building supervisory authorities, and the administrative procedure from the building application.