The conversation around San Diego’s vacation rental homes has been loud and heated for years. Meanwhile, an equally large part of the housing stock has received much less attention: empty second homes. They are, in many cases, the vacation homes of the very-wealthy and they spend much of their time sitting empty. The list of vacation homes, created by Councilmember Sean Elo-Rivera’s office, is based on residences which claimed exemption from the rental unit business tax. La Jolla’s ZIP code alone has 852 vacation homes.