Electrochromic device with separately controllable zones

An electrochromic device comprising:

• a first substrate having a first conductive surface;
• a second substrate having a second conductive surface;
• an electrochromic medium disposed between the first substrate and the second substrate;
• a first busbar spaced apart from a second busbar and both in electrical communication with the first conductive surface of the first substrate;
• and
• a third busbar spaced apart from a fourth busbar and both in electrical communication with the second conductive surface of the second substrate,
• wherein:
• at least one of the first conductive surface and the second conductive surface is substantially transparent;
• the first busbar is externally electrically connected with the third busbar to define a first zone;
• and
• the second busbar is externally electrically connected with the fourth busbar to define a second zone.

A method comprising:

• connecting a first busbar of a first substrate of an electrochromic device to a third busbar of a second substrate of the electrochromic device to form a first electrical circuit and define a first zone;
• connecting a second busbar of the first substrate of the electrochromic device to a fourth busbar of the second substrate of the electrochromic device to form a second electrical circuit and define a second zone;
• and
• applying a voltage across the first electrical circuit in a closed circuit to obtain a first transmissive state in the first zone.