The requirements of city buildings, which are for the main part similar to the practices which we have already considered, are, nevertheless, in many essentials, distinct. In the first place, the circumstances of situation, soil and surroundings differ from suburban or rural conditions. Instead of being able to establish our building to meet our individual tastes, we shall find that the sidewalk and yard levels are already established, and the level of the cellars or basements will be found to be restricted in some localities. The lines of our building will also be determined, in a great measure, by established lines and restrictions so that much more of preliminary work will be needed to make the most of the existing conditions with which we find ourselves confronted.