The Massachusetts Appeals Court ruled today the owners of half of a two-unit condo can't build dormer windows without their neighbors' consent.
The ruling comes in the case of a former duplex in Newton in which the owners of one side wanted to extend their attic with dormer windows and a deck, but the owners of the other side balked. The dormer people sued, seeking arbitration, but the appeals court says state condo laws are very specific: The roof is a "common area" owned jointly by all owners and that if one owner doesn't want to modify it and change the overall size of the area, there's nothing the other owner can do:
... The condominium statute explicitly requires that all owners give consent before their percentage interest in the common areas is affected; all portions of the plaintiffs' proposal that would do so are therefore impermissible without the defendants' consent. ...