Both the building and the park are projects of Matrix Development Group, based in Cranbury. Terms of the signing were not disclosed. Iron Mountain is expected to move into the building shortly.

"This long-term lease demonstrates the great demand for industrial product in the New Jersey Turnpike Exit 8A marketplace," says Alex Taylor, chief operating officer of Matrix. The building itself was vacated last year by WW Grainger, the manufacturer and distributor of facility-related products for commercial, industrial and other users, which had been utilizing it for warehousing and distribution purposes. Matrix originally developed the asset for WW Grainger in 1995 and sold it to the company.

Matrix then bought the building back from Grainger a year ago in a deal that coincided with the latter's move to another, larger Matrix-owned facility. The sale price was not disclosed, but industry sources at the time put the number in the $15-million range. Grainger subsequently moved to its new quarters, a 436,000-sf building in Matrix's Northeast Business Park in Washington, Township, in the Exit 7A market, and Matrix put the re-acquired 26 South Middlesex Ave. building on the market for lease.

The Boston-based Iron Mountain's new location occupies a 30-acre site that has room for an additional 120,000 sf of industrial space. The facility has 28-foot clear ceiling heights, 43 loading doors and a built-out office space component of 10,000 sf, according to Taylor. Matrix Development's work tab in the New Jersey marketplace now totals more than five million sf of industrial leases and sales in just the past 24 months.