Groupe E a promoter of district heating networks was confronted with the possibility of building a network of this nature in the municipality of La Tour-de-Peilz. The munici- pality imposed a situation where the lake water should be used for heat pumping. By mapping the heat demand with the help of Geographical Information System (GIS) tools and a database manager it was possible to simulate the thermal behavior of the build- ings within the bounds of the municipality. To carry on an analysis on the performance of several heat supply scenarios, industrial process integration techniques were used to verify the performance of different technologies in the basis of environomic indicators. The base case in the municipality being a traditional boiler, was then compared on the basis of these indicators. It was found that for the buildings existing in the municipality, the best choice is to install high temperature heat pumps that do not perform as well in terms of exergy efficiency as low temperature heat pumps but they can create the bridge between the goal of the promoter and the pollution mitigation. With this solution, re- ductions of 98& in C O2 equivalent green house gases is achieved and an increase of 64% in the exergy efficiency of the chain of enerdy conversion.