The post and beam system is the system dedicated for completing casing walls, roofings, skylights, classified as the RMG 1.0 material group member. The width of posts and beams is equal to 52 mm, masking units: 51 mm. With the application of the specially designed and dedicated insulating unit, the casing wall may be completed with the overall heat transfer coefficient at the level of 1,75 W/m2K. Technical solutions allow constructing straight walls or bend shaped walls, transition of exterior and interior angles and adaptation to the winter gardens. The system provides the solutions with steel and timber substructure.