SAN RAFAEL -- As the county of Marin prepares to take ownership of a 328,000-square-foot office building in north San Rafael in December, preparations are under way to start the estimated $53.1 million transformation of a large portion into the county's Emergency Operations Facility in mid-2012.

San Mateo-based Sares Regis Group of Northern California, which manages the 455,000-square-foot two-building Marin Commons complex, plans to circulate requests for qualifications and proposals to its select group of vendors in the first quarter of next year to allow construction documents to be ready for work to begin, according to a spokesman.

"Construction should begin by summer -- in the second or third quarter -- and run for 12 to 18 months," Gary Pike said.

The county Board of Supervisors on Nov. 15 approved the purchase of the mostly vacant office building at 1600 Los Gamos Drive for $29.5 million from an affiliate of Connecticut-based Cigna Real Estate. Then the county intends renovate about 100,000 square feet in the north end of the building, upgrading the 24-acre site and purchasing furniture, fixtures and equipment. The new emergency center will house the Sheriff’s, Information Services and Technology and Public Works departments.

The county chose to set up the new center in an existing building rather than erecting a new structure. Cigna foreclosed on Marin Commons in 2009 and brought in Sares Regis to reposition the property in April 2010. Cigna and the county were in talks about a significant occupancy in the complex for more than a year.

During renovations, the county plans to shuffle various departments to make best use of space, according to David Spear, head of county real estate. About 80,000 square feet of vacant space at 1600 Los Gamos for will be for temporary uses, such storage for the Registrar of Voters and during work on a county-owned building at 20 N. Pedro Rd. By 2015, several departments now leasing 30,000 square feet in four buildings will be relocated into Civic Center space vacated when the Los Gamos center is finished by mid-2014. 

Three major tenants now in 1600 Los Gamos -- Bright Horizons, the IRS and THX -- will continue to occupy about 55,000 square feet, leaving 63,000 square feet of office space and 20,000 square feet to lease.

Local commercial property experts have been eagerly anticipating the county’s action on Marin Commons, one of the largest office properties in the county, because large vacancies has inflated the Marin office availability rate, at 18.1 percent in the third quarter, according to Cassidy Turley BT Commercial. Marin Commons was designed for one or a few large tenants, making it functionally obsolete for most Marin tenants.

"North San Rafael been slow for several years," said Trevor Buck of Cassidy Turley BT.