This paper aims at understanding how the aerodynamic performance of a hovering microrotor is affected by horizontal and vertical wall proximity. Toward that end, experiments are performed to extract aerodynamic loads and velocity flow fields from strain gauges and high-definition stereoscopic particle image velocimetry measurements, respectively. The results show that horizontal wall boundary conditions contribute to enhancing aerodynamic performance, whereas vertical boundary conditions have a negligible impact. Enhancement of aerodynamic performance arises from distinct flow physics, such as rotor wake expansion or Venturi effects, that depend on the configuration considered. These results open the path toward the development of micro air vehicles dedicated to the exploration of highly confined environments.