Twenty feet is the starting rule
Distance is measured from the occupied structure, not merely the nearest open window. Wind can change, so point exhaust away and avoid places where fumes can collect or be pulled inside.
A garage with the door open, carport, shed, or covered porch is not a safe indoor substitute.
Plan cords and weather protection
Choose outdoor-rated cords with the correct gauge, length, current rating, and connectors so a safe generator location is not abandoned because the cord is too short.
Use purpose-built operating protection that preserves cooling and exhaust clearance. Never enclose a running generator with a tarp or improvised box.
Use alarms as backup protection
Install carbon-monoxide alarms on every level and near sleeping areas according to their instructions. Test and replace them on schedule.
A generator's CO shutoff and indoor alarms add protection, but neither changes the outdoor placement rule.
Frequently asked questions
Can I run a generator in an open garage?
No. Carbon monoxide can accumulate and enter the home even with the garage door open.
Is 10 feet far enough?
CDC guidance says at least 20 feet, with exhaust directed away from occupied structures and openings.
Can a generator sit under a porch?
Do not use a location where exhaust can collect or enter a building. Follow the manufacturer and public-health guidance.
Sources and verification
We prioritize public-health guidance, official manuals, and manufacturer specifications. Always check the current manual for the exact model you purchase.