Smoke detectors built-in and connected so all go off together (big, well-insulated house-may not hear one going off ma distant room) with battery models as back-up
multiple fire extinguishers
Pool pump valved and connected to supply small fire hose with B/U genny power
Reinforced door hardware
Motion-sensing exterior lighting
TRAINED watchdog (not attack dog)
Roof reinforced against high wind (braced, screwed, glued)
Friendly with good neighbors
Stored food & water, survival gear, extensive first aid supplies
Stored repair, loss mitigation, clean-up, and salvage tools & supplies
Sufficient insurance
Well-laid, documented emergency plans
etc...
Jeff