The distinctive atmosphere (for better or for worse) of Beverly Hills didn’t just fall from the sky. You might not know it from the rampant demolition of historic buildings or some of the new Styrofoam-enhanced construction techniques, but Beverly Hills has a stringent set of building codes. I enjoyed the city’s film “It’s a Wonderful City,” a short comparing their town to one without zoning laws. It’s set to the tune of “It’s a Wonderful Life” and a good answer to folks complaining that they can’t build to the lot line or squawking about a requirement to plant trees. Jimmy Stewart’s own stone-and-timber Tudor style home on Roxbury Drive was replaced with a Mega Mediterranean in 2000. Roxbury Drive needs a guardian angel.