The “ancient lights” doctrine, from English common law, said that a property owner could prevent a neighbor from erecting a structure that blocked the sunlight he had been enjoying. Proclaiming that the importance of towns and villages superseded such broad property rights, US courts ignored the “ancient lights.”
However, if you block the sun in California, you could be sued.
In 2008, a Santa Clara homeowner who was just planning to install solar panels asked his neighbor to trim the redwoods that were blocking the sun. They wound up in court. Citing California’s 1978 Solar Shade Control Act, the judge said 2 of the 8 the trees would have to be cut down. (Elsewhere, I read that just one of the trees had to be pruned.)
Subsequently, the law was amended. Now, trees that violate solar access laws have to have been planted after solar panels are installed.
A question: Thinking of 5th Avenue or a tree lined California neighborhood, should the sun be a property right that you can retain through a court of law?
Sources and resources: Including a 5th and Madison Avenue graphic, this NY Times article conveys the value of the sun and other variables that inflate commercial rents. Then, on the residential side, the California court case described here and here is a fascinating example of the how the sun can be a part of your property rights. Please note that several sentences appeared in a previous econlife post.