Complex sentence: For a short time between 1952 and 1953 he gave lectures on color and proportion to architecture classes at the Ecole des Beaux-Arts, and in his subsequent years he worked together with architects and was otherwise part of the planning for the expansion of Le Havre.
Split into simpler sentences: For a short time in 1952-3 he lectured architecture classes at the Ecole des Beaux-Arts on color and proportion. In the following years he worked together with architects and was otherwise part of the planning for the expansion of Le Havre.