Image courtesy IQHQ

A Cambridge construction materials manufacturer will occupy its 290,000-square-foot headquarters rent-free for 18 months after the pending sale of the property for $125 million to a life science developer.

GCP Applied Technologies has an option to extend its leaseback for an additional six months as the new owners, IQHQ Inc., review development options for the 26.5-acre site known as Alewife Park on Whittemore Avenue in the Alewife section.

The complex contains office, lab and R&D space for GCP, which makes cement and concrete additives.

Cambridge officials have been studying rezoning options for the Alewife area as more developers acquire commercial properties with plans for more office and lab space. The city’s Alewife District Plan released last fall suggested the best use for the Whittemore Avenue subdistrict is median-density residential.

In a statement, IQHQ President Tracy Murphy said the firm will discuss options for the future of the property with Cambridge officials and residents.

IQHQ, which raised $770 million for acquisitions in a handful of life science clusters including Greater Boston, previously acquired 4 Corporate Drive in Andover for $36 million and 109 Brookline Ave. in Boston for $270 million. The REIT also is partnering with Boston-based Meredith Management on its Fenway Center air rights project which will include two office-lab towers totaling 720,000 square feet.

Newmark Knight Frank’s Boston Capital Markets Group represented GCP in the transaction, which is expected to close by early August.