<p>The window system has microprocessors (43) coupling the pivoted windows (41) to a central monitoring point (49) which incorporates an optical display for the closed and locked positions of each window (41). The microprocessors (43) lie adjacent the respective windows (41), each incorporating a receiver for remote control signals supplied by the central monitoring point (49), with auxiliary control of each window via a portable remote control transmitter (63) and via stationary control devices (67) receiving room parameter sensor signals. Pref. the sensors (69) detect the relative humidity, the temp. and/or the CO2 content of the room air.</p>
