Techniques for heating and/or cooling a structure including are described. The system may determine that a current indoor temperature is higher than both the current outdoor temperature and the target indoor temperature. Based on the determination, the system (in a cooling mode) may determine that a window opening criteria is met for opening one or more windows. Responsive to determining that the window opening criteria has been met, the system may instruct a window control mechanism to modify a state of the window from (a) a closed position that prevents airflow through the window to (b) an open position that allows for airflow through the window to cool a structure. Similarly, the system in a heating mode may open one or more windows when the current indoor temperature is lower than both the target indoor temperature and the current outdoor temperature.