To provide a remodeling method suitable for an old coating film of organic paint formed on an outdoor side surface of a heat insulating wall.

At least one kind of coloring paint is applied to an old coating film surface formed on the outdoor side of a building exterior wall. This wall is a heat insulating wall of a heat transmission coefficient of 5.0 W/(m2K) or less. The old coating film surface has a coating film formed of paint of using an organic resin as a binder. A material of including a synthetic resin emulsion of the glass transition point of -20 to 80 C as the binder and forming the coating film of infrared reflectance of 20% or more and steam permeability of 40 g/m224 h or more, is used as the coloring paint.