Any housing authority now or hereafter established pursuant to N.H. Rev. Stat. Chapter 203 may carry out as a redevelopment project or as a part of a redevelopment project in any area in which a redevelopment project is determined to be necessary by a housing authority, any work or undertaking to develop or redevelop an area of vacant or predominantly vacant land which is substandard or blighted or in the process of becoming blighted (1) because it is unduly costly to develop or redevelop such an area through the ordinary operations of private enterprise (a) by reason of the existence of ledge, rock, unsuitable soil or other physical conditions or because of the necessity for unduly expensive excavation, fill or grading, or (b) by reason of the need for unduly expensive foundations, retaining walls or unduly expensive measures for waterproofing structures or for draining the area or for the prevention of the flooding thereof or for the protection of adjacent properties and the water table therein or for unduly expensive measures incident to building around or over rights-of-way through the area or for otherwise making the area appropriate for sound development, or (2) because obsolete, inappropriate or otherwise faulty platting or subdivision, division of the area by rights-of-way, diversity of ownership of plots, inadequacy of transportation facilities or other utilities, inadequacy of access to the area, tax and special assessment delinquencies, a substantial change in business or economic conditions or practices, a deterioration of site improvements or facilities, an abandonment or cessation of a previous use or of work on improvements begun but not feasible to complete without the aids provided by this chapter or any combination of the foregoing or other conditions in any such area which are not being remedied by the ordinary operations of private enterprise, result in any such area not being used at all or result in any such area being used in an unplanned, haphazard, or piecemeal manner with building on small parcels or sections of any such area without any overall plan or design, so that in essence any such area is detrimental to the safety, health, morals, welfare or sound growth of the community in which it is situated. The powers granted in this section are in amplification of and in addition to the powers granted in N.H. Rev. Stat. § 205:2 and 2-a, with respect to the inclusion of areas of vacant or predominantly vacant land in a redevelopment project. Notwithstanding the provisions of paragraph VI of N.H. Rev. Stat. § 203:3, the authority conferred by this section shall be exercised only within the territorial limits of the municipality for which the housing authority is created.