The present paper shows that existing two- or three-column sequences could be transformed in a cost-effective way into a dividing wall column (DWC) to allow for energy saving equivalent to that achievable in new designs. This makes DWC an interesting retrofit option for process industries willing to achieve a substantial reduction in energy requirement and carbon dioxide emissions in existing plants. Additional benefit is reflected in the potential for increasing substantially the capacity of existing units in the most sustainable way.@en