An electrochromic window assembly includes: a first transparent substrate having a first conductive coating on a surface thereof; a second transparent substrate having a second conductive coating on a surface thereof, the first transparent substrate and the second transparent substrate being spaced from each other to define a chamber therebetween; an electrochromic medium contained in the chamber, the electrochromic medium having a luminous transmittance that varies upon application of an electrical potential through the electrochromic medium; a plurality of first spaced facilities contacting the first conductive coating and capable of delivering electrical current to the first conductive coating; and a plurality of second spaced facilities contacting the second conductive coating and capable of delivering electrical current to the second conductive coating to establish the electrical potential through the electrochromic medium. The plurality of first spaced facilities and the plurality of second spaced facilities can be bus bars arranged about the perimeter of the window assembly. In addition, the window assembly can include a controller capable of controlling delivery of electrical current to selected ones of the plurality of first spaced facilities and selected ones of the plurality of second spaced facilities, such that the luminous transmittance through a first portion of the electrochromic medium is different from the luminous transmittance through a second portion of the electrochromic medium.