Change is coming to the historic, clock-capped Empire Building on Santa Rosa’s Old Courthouse Square.

It is up for sale and its primary tenant — one of Sonoma County’s oldest law firms — is moving out.

“Our first reaction was kind of sad,” said Patrick Grattan, senior partner of the Geary, Shea, O’Donnell, Grattan & Mitchell firm. But then, he said, the attorneys found that an entire floor was available at the contemporary office building at E Street and Sonoma Avenue, home also to the prominent law firm of Spaulding McCullough & Tansil.

The Geary firm will move into the top floor at 90 E Street by the end of the year.

Fifty years have passed since the prestigious law firm moved into the Empire Building. The late Bill Geary his father, late Sonoma County Superior Court Judge Donald Geary, settled their practice in the four-story tower, originally the home of Santa Rosa Bank, in 1964.

Geary Law has come to occupy more than half of the office space in the structure, built after the preceding home to Santa Rosa Bank was destroyed by the earthquake of 1906.

Ownership of the building has changed hands a number of times over the decades. The Bank of America had moved out when leading Sonoma County financier and philanthropist Henry Trione bought it 1956. Five years later, Trione co-founded within its walls the Empire College business school.

The Empire Building is owned currently by a partnership, Empire Building Associates, the partners in which include some of the attorneys with the Geary firm.

Said partner Steve Mitchell, “We bid fond farewell to the Empire Building and we were proud to call it home for many years.” He added that a bonus of the new location is that it’s across E Street from the Federal Building named in honor of Jack Shea, the longtime Democratic Party leader and partner in Geary Law who died in 1985.