Like many older buildings, the Library needed improvements in a number of areas. But the record did not establish that it suffered from obsolescence, faulty arrangement, or obsolete layout in a way that harmed the welfare of the community. To designate property for redevelopment under the LRHL, a municipality must demonstrate that certain specified problems exist and that they cause actual detriment or harm. There is insufficient evidence in the record to meet that standard. The designation of the Library as an area in need of redevelopment is invalid.