2 Time to read: about 1 minutes The Contra Costa County Board of Supervisors officially asked staff Tuesday to craft an ordinance amending the county building code to require electricity to be the sole source of power for all new residential and non-residential (hotel, office and retail) buildings, while prohibiting the installation of natural gas piping. The board voted 4-1, with Supervisor Candace Andersen dissenting. Andersen said she wanted to see more details on sustainability and infrastructure and believes homeowners should have more options. "It's important they have an opportunity to weigh in," Andersen said, referring to municipal advisory councils and others in unincorporated areas.