A new California building code is a leap forward for reducing the use of natural gas, with rules that set a strong preference for electric heating in new construction. That’s the glass-half-full view of the rules the state’s energy commission approved last week, according to environmental advocates. But many of those same people wanted much more. They had hoped that California would become the first state in the country to ban natural gas in most new construction, at a time of growing awareness of the health and climate benefits of all-electric buildings. Now, advocates are looking to other states that may be the first to pass some kind of gas ban, with candidates that include Massachusetts, New York and Washington. […]