A method for providing at least a part of a building includes the steps of prefabricating a module by assembling four walls extending between a floor and a roof to form a rectangular cuboid shape; providing at least one compartment within the cuboid shape; providing waterproof layers on the interior walls and floor of the compartment for creating a wet area within the module; arranging technical installations within the cuboid shape; and providing interior equipment within the cuboid shape. The method further includes the steps of prefabricating a plurality of panels and slabs; and connecting these panels and slabs to a lateral side of the module for providing a further rectangular cuboid shape forming a panel-built room.