This work presents a methodology for heat exchanger network (HEN) retrofit, which is applicable to complex industrial revamps, considering existing networks and constraining the number of modifications. The network pinch approach [N.D.K. Asante, X.X. Zhu, An automated approach for heat exchanger network retrofit featuring minimal topology modifications, Comp. Chem. Eng. 20 (1996) S7-S12.] has been modified and extended to apply to the HEN design in which the thermal properties of streams are temperature-dependent. The modified network pinch approach combines structural modifications and cost optimisation in a single step to avoid missing cost-effective design solutions. © 2010 Elsevier Ltd. All rights reserved.