In 2007, New Jersey enacted legislation preventing homeowners associations from prohibiting the installation of solar collectors on certain types of residential properties. The term "solar collector" is not defined, but would seem to include both solar photovoltaic and solar thermal technologies which use collectors installed on the roof of a dwelling. This law covers only dwellings that are not deemed community property of the association, including townhouses which have at least two sides that are unattached to any other building and for which the owner, rather than the association, is responsible for roof maintenance. In addition, the law applies specifically to systems installed on the roofs of qualifying dwellings. Presumably this means that it does not extend the same protections to ground mounted systems. A homeowners association is permitted to regulate certain aspects of solar collectors, including the qualifications of installation personnel, collector location, concealment and size. However, any regulation that would increase the collectors' installation and maintenance cost by greater than 10%, or would prevent the system from operating at maximum efficiency, may not be enforced.