Maximizing heat recovery in the process industry is important to cut primary energy targets. It is always the trade-off between saved energy and spent capital investment. This issue became more important in the transition to a low-carbon economy. Inter-plant integration can be a source of clean energy, which does not need to be produced but proper targeting gives its economic feasibility and attraction to investments. This paper provides a new extension of the Total Site method accounting optimal amount of energy that can be saved on the inter-plant level. The approach utilises the construction of the Total Site Profiles with real temperature considers heat transfer with intermediate utility and finds cogeneration potential within enthalpy blocks of Total Site heat recovery. Merging of intermediate utilities and optimisation of its temperature were considered together with CHP optimisation. Targeting of the total annual cost was performed based on Total Site Pinch concept finding the optimum temperature approach between site temperature profiles. The case study for monomer production of polymer plant was investigated and 6 different options of Total Site heat recovery were assessed. The minimum total annualised cost of 45.3 mils. EUR was accounted for option with maximum cogeneration potential and the minimum number of heat exchangers. The heat recovered is 160.7 MW, CHP potential is 32.9 MW, and the number of heat exchangers is 144 for a total site minimum temperature approach of 20 °C. The results were compared with the traditional Total Site approach and the advantages were highlighted. The sensitivity analysis of the results was performed by applying energy price changes of ± 50% of the base level. The results can be used for the detailed design of the site energy system and further development of Total Site methods.