An external door opening to a conditioned space must also have a device to prevent significant amounts of conditioned air being continuously lost. This only applies to conditioned spaces greater than 50 m2. Devices that may be installed to comply with this requirement may include an airlock, self-closing door, or revolving door. Provisions for people with a disability should also be considered when selecting the device.

There are a couple of exemptions to these requirements, such as for roller shutter doors or the like, that are used for out-of-hours security purposes only, i.e. when conditioning is not operating. Another exemption has been granted for the main entrance to a café, restaurant or open front shop that has a 3 m non-conditioned zone. Where staff are carrying trays of food or drink it may be unsafe to require an airlock, self-closing door or sliding door.