In determining whether dwelling accommodations are unsafe or unsanitary, the council shall take into consideration the following:
(1) the physical condition and age of the buildings;
(2) the degree of overcrowding;
(3) the percentage of land coverage;
(4) the light and air available to the inhabitants of such dwelling accommodations;
(5) the size and arrangement of the rooms;
(6) the sanitary facilities; and
(7) the extent to which conditions exist in such buildings which endanger life or property by fire or other causes.