As used in sections 12-65c to 12-65f, inclusive:

(a) “Rehabilitation area” means any municipality, or a part thereof, that contains one or more properties that are deteriorated, deteriorating, substandard or detrimental to the safety, health, welfare or general economic well-being of the community;

(b) “Rehabilitation” means the improvement or repair of a structure or facilities appurtenant thereto, exclusive of general maintenance or minor repairs.