In 1934 Andreani won the competition for the town plan of Mantua. July 23, 1940 he was officially appointed by the municipality. His reinterpretation of the plan was submitted to the Superintendence for approval January 1941; the project was only partially approved in September. Work began on Palazzo della Ragione, with the elimination of the eighteenth century elements, and with the addition of the battlements. In September 1942, the floor of the hall was laid. The demolition of the portico brought on a fierce polemic. In 1943 the parts of the buildings on the side of Via Giustiziati were modified, including the Arengario. Finally, in 1944 Andreani attempted to gain permission to make some drastic changes to Palazzo del Podesta, the war however put an end to his plans.
In this image we can see how he intended all houses to be removed from Piazza Erbe, houses which dated to the fifteenth century, that partially impede the view of the right transept of the church of Sant'Andrea.