There is a lack of scientific research regarding EWSS. Other issues that may affect the effectiveness of an EWSS:
* Sprinkler performance in high wind conditions typical in a bushfire
* Home design
** High vulnerability areas.  e.g. decking
** Garden beds near walls
** Window sills
** Large windows (heat radiation)
** Internal furnishings (e.g. curtains)
* Home location
** Slope
** Surrounding vegetation
* If defended by occupiers
* Preparation (if prepared for defense)
* If intended for remote (unattended) defense
* Available water supply
* Ember attack
* Fire front (radiant heat)
* Adjacent building or vegetation fire