There's nothing here to stop anyone installing as many or as few lights as he likes on his own house, unless a sign could be taken to be an advertisement, in which case it might need a permit from the local council, but that's nothing to do with energy conservation.
Many of the government agencies in recent years have implemented "energy awareness" programs and such like, suggesting that people use low=power compact fluorescents etc. but there's no compulsion.
"Light pollution" has become a concern in recent years, especially as our houses tend to be packed into towns to a much greater density than in the U.S.A.
