In the month of September alone, G-H traded 724 units for more than $54 million.

G-H markets all types of apartment buildings in both urban and suburban locations, as well as office and retail properties. But multi-family has become the “blockbuster heart, soul and muscle” of commercial real estate trading, Uranowitz says.

Mack-Cali had signaled at the end of last year it was training its sights on these trends when it announced a joint venture with Ironstate Development to add a high-rise residential tower to its Harborside Financial Center in Jersey City. Last December, Hartz Mountain Industries – another company that had predominantly focused on office developments – broke ground on a joint venture with Roseland to build apartments in Weehawken.

After Mack-Cali’s announcement Tuesday that it will actually swallow Roseland whole, the architect of the deal – Bruce Schonbraun of FTI Consulting - described it as a “strategic, transformational diversification” for Mack-Cali, which is one of the largest owners of Class A office space in the region.

Uranowitz says that virtually all of the “smart money” is flowing and shifting into multi-family residential development and trades right now for these reasons:

• New Jersey residents are flocking to a post-recession lifestyle of apartment living, due to affordability and the appeal of transit-oriented locations.
• That steady stream of demand positions multi-family property as a stable investment in a generally uncertain marketplace
• Historic low interest rates are generating unprecedented building sales.

Mack-Cali and Roseland as separate companies have focused squarely on developing Class A portfolios, with both developing signature properties on the Hudson riverfront – Mack-Cali’s Harborside, for example, and Roseland’s Port Imperial residential complex.

Uranowitz notes that investment activity is percolating at all levels of multi-family, however, including “B, C, even D – if there is such a thing as D.”