A system and method is provided to construct a structure using three dimensional printing of extrudable building material to a wall surface of a structure. According to one embodiment, a printing assembly is moveably disposed above the surface, and extrudable building material is applied from a nozzle onto the surface. One or more profilometers measure at periodic intervals along a geometric cross-section of a bead of extrudable building material. One or more controllers compare the measured cross-section to a predetermined, target cross section and one or more controllers periodically change, for example, the rate of application and/or the viscosity of the extrudable building material applied along the longitudinal axis. The nozzle direction can change, and the profilometers can be rotated about the nozzle along different longitudinal axes, or directions, depending on the wall locations being formed.