Maintaining the indoor thermal comfort characteristics of a house by modulating natural ventilation is particularly challenging, as the solution is not explicit. Determining a solution requires solving the complexity, dynamics, and nonlinearity associated with the natural ventilation driving forces and building thermal behavior. However, prior to finding any solution to this effect, the potential of regulating thermal behavior of the building with respect to different operating conditions needs to be examined in detail. Previous studies have found that there is some scope for regulating the thermal behavior of relatively air-tight house by opening or shutting the window. As such, this work utilises dynamic simulations to examine the variation of thermal comfort, in terms of the Predicted Mean Vote (PMV), of a model house equivalent to a size of a typical room under NZ climatic condition and for various operating conditions. To achieve this, it examines the PMV of the room with various Window Opening Fraction (WOF), different air-tightness values and different level of envelope thermal resistance utilizing coupled thermal and airflow simulations. This work demonstrates that the scope for regulating the thermal comfort behavior of a naturally ventilated residential house improves with a relatively well-insulated envelope.