To some extent the answer depends on what type of phlox you have. The woodland and stoloniferous creeping phloxes would do fine on the north side of the house in partial shade or morning sun, and creeping phlox (P. subulata) would do fine on the south side. Carolina phlox would probably be okay on either the south or the east side as it is a fairly adaptable plant. The tall garden phlox (P. paniculata) however, prefers full sun with a good rich and evenly moist soil, needs good air circulation and should not be watered from overhead if at all avoidable. You might want to experiment and see which of these locations works better.