''Decadent area'', an area which is detrimental to safety, health, morals, welfare or sound growth of a community because of the existence of buildings which are out of repair, physically deteriorated, unfit for human habitation, or obsolete, or in need of major maintenance or repair, or because much of the real estate in recent years has been sold or taken for nonpayment of taxes or upon foreclosure of mortgages, or because buildings have been torn down and not replaced and under existing conditions it is improbable that the buildings will be replaced, or because of a substantial change in business or economic conditions, or because of inadequate light, air, or open space, or because of excessive land coverage or because diversity of ownership, irregular lot sizes or obsolete street patterns make it improbable that the area will be redeveloped by the ordinary operations of private enterprise, or by reason of any combination of the foregoing conditions.
''Department'', the executive office of housing and livable communities.
''Development cost'', the cost of construction or acquisition of a housing project, as determined by the department, including the costs of planning, engineering, surveying and studies; of acquisition of real estate, including the buildings thereon, site preparation, construction, reconstruction, alteration and repair; of interest on notes issued to temporarily finance the project; and of all other fees and expenses reasonably necessary and incurred or to be incurred in connection with construction or acquisition of a housing project.
''Elderly persons of low income'', persons having reached the age of sixty or over whose annual income is less than the amount necessary to enable them to maintain decent, safe and sanitary housing.