The design of developments to effectively utilize natural ventilation strategies within mechanically ventilated buildings can minimize energy use and provide fresh outdoor air to building occupants. Natural ventilation strategies should provide for an adequate flow of air within occupied spaces to ensure appropriate thermal comfort conditions. In buildings employing a naturally ventilated system, it is recommended that the total area of operable windows is at least 5% of the total floor area of the room to provide for effective ventilation. In addition, more than 90% of all occupied spaces should be designed for cross-ventilation.