The contribution points out the topic of the value of urban space in the perspective of the economic history and it examines Clerici family real estate investments. The Clerici were silk merchants who moved to Milan at the beginning of the 17th century and became protagonists of a rapid social ascent culminated in 1737 with the admission in the patriciate. The article, after a rapid survey of the investment strategies of the Clerici, from the land acquisitions to lending activity, dwell upon their action on the Milanese real estate market. Firstly are reconstructed Clerici choices with regard to real estate. Their purchases turn out to be concentrated in the area of Porta Comasina and follow two different logic. The former careful to social standing and culminated in the construction of a splendid palace, the latter instead careful to business, with the purchase of shops and buildings in strategic position for commerce. Secondly it was considered how Clerici managed their buildings in Milan with special regard to sales and rents. In this way it has been possible to notice the advantages in owning a building. In fact this kind of property allowed to preserve and transmit a value, to assure an income by means of rent, to obtain loans.