Diamond Bar residents are invited to take a tour of Diamond Bar’s brand new city hall, today from 4 to 6 p.m. It officially opened for business last month.

The opening marked the first time in its 22-year history that the city is operating from its own building.

Employees formally worked out of a South Coast Air Quality Management District complex that the city shared with the agency.

Diamond Bar purchased its new building at 21810 Copley Drive in September 2010 with the dual goal of addressing space needs for city operations and creating a new home for the nearly 40-year-old library branch.

The building’s first floor and future library site will not be open for tours Tuesday because it is still under construction. Completion is planned for this summer.

With 27,000 square feet of space, the second floor houses all city government service functions, a team of Los Angeles County Sheriff’s Department personnel and an Emergency Operations Center. It also features a large public service counter and several meeting rooms.

City Hall’s open house will take place from 4 to 6:30 p.m. For more information, contact Diamond Bar’s public information office at 909-839-7055.