In a building with double-layer walls insulated with the method “light-wet ”solution of the contact between external walls and a retaining wall is much easier to implement – thermal insulation of basement walls acts as a dilatation between the structural wall and the retaining wall perpendicular to it. In the hopper, heat-insulating boards made of extruded polystyrene protect the vertical waterproofing against earth pressure. In a part of the basement wall, out of the ground, insulation boards are finished with the "light-wet" method with a moisture-resistant acrylic plaster and with a double reinforcing mesh in the adhesive layer. Vertical waterproofing in the part of the building with a higher backfill level is installed over the entire surface of the basement wall and rolled up into horizontal cut-off insulation under the ceiling rim above the basement. In the exposed part - with a lowered level of the surrounding area – the waterproofing is led out on 30 cm above the ground.