Six months after urban wildfires devastated neighborhoods in Los Angeles, signs of rebuilding are evident. Although the landscape still resembles a charred war zone, many residential lots have been cleared with assistance from FEMA. In Altadena and Pacific Palisades—the communities that, together, lost more than 16,000 structures—some homeowners are overcoming huge hurdles, such as permitting and steep construction costs, and are expected to begin rebuilding this year. And builders are banding together in a new Builders Alliance to share resources and incrementally ease the massive housing shortage that plagued the city even before the fires.