In the 1980s, he participated in planning and management teams for the construction of IDF bases in the Negev, which were relocated from Sinai after the signing of the peace treaty with Egypt.
In the mid-1980s, he developed a method for initiating projects in an innovative format, where the final consumer is actually the entrepreneur who purchases the land property and who orders construction services, and it is that entrepreneur who benefits from the saving of entrepreneurial profit. This format eventually became known as the genesis of purchasing groups in Israel.
Kalman has planned and carried out dozens of residential, office and commercial purchasing group projects, including B.S.R. Towers 1 and 2 in Ramat Gan and Bnei Brak, Gibor Sport Tower in Ramat Gan, Manhattan Tower in Tel Aviv's Park Tzameret, Toyota Towers in Tel Aviv, and more. On these projects, he engaged in locating the project, forming the group of final consumers and providing all planning, supervision and management services as well as handling the banking accompaniment until occupancy, while maintaining full collaboration and coordination with all partners.
In the course of his activity, he has initiated, managed and founded dozens of projects in Eastern Europe and the United States, and has won many prizes.
Nowadays, he serves as Chairman of the Sufrin Group.