Palacio de Letrán
Among secular buildings his strong restrained style, with its suggestion from Jacopo Barozzi da Vignola, is best exemplified in the Lateran Palace (begun in 1586), in which the vigorous application of sound structural principles and a power of co-ordination are undeniable, but also the utter lack of imagination and barren monotony of style. It was characteristic of him to remain satisfied with a single solution to an architectural problem, as shown in the fact that he reapplied the motif of the Lateran Palace in the later part of the Vatican containing the present papal residence, and in the additions to the Quirinal Palace.