Building regulations. These regulations limit the height, bulk and location of buildings hereafter erected, standardize the area of yards, courts and other open spaces, and determine the density of population in any given area and for said purposes to divide the City into districts. Such regulations shall be uniform for each class of buildings throughout any district, but the regulations in one or more districts may differ from those in other districts. Such regulations shall be designed to secure safety from fire, flood and other dangers and to promote the public health and welfare, including, so far as conditions may permit, provision for adequate light, air, convenience of access, and the accommodation of solar energy systems and equipment and access to sunlight necessary therefor, and shall be made with reasonable regard to the character of buildings erected in each district, the value of land and the use to which it may be put, to the end that such regulations may promote public health, safety and welfare and the most desirable use for which the land of each district may be adapted and may tend to conserve the value of buildings and enhance the value of land throughout the City.