How Far From a House Should a Generator Be?

Gary Sprague

Portable generators should be placed 20 to 25 feet from an inhabited area to eliminate the risk of carbon monoxide poisoning.

How Far From a House Should a Generator Be

When a storm strikes and the power is out for days or even weeks, a generator can literally be a lifesaver. But a generator also emits dangerous exhaust fumes which, if placed too close to a house, can be deadly.

What is a Safe Distance?

Portable generators emit carbon monoxide at a rate much higher than that of a car's exhaust because of the lack of emission controls. A safe operating distance depends on the house, weather conditions such as wind and temperature, and the generator itself. Slow winds in particular can increase the risk of poisoning by causing carbon monoxide to linger near windows. If possible, check local codes for generator safety requirements. Although many municipalities require a placement of 10 feet from any structure with the exhaust facing away from building openings, a minimum of 20 feet from the building is recommended to prevent carbon monoxide poisoning.

Portable Generators

Portable generators are often seen on construction sites, providing electricity until the power is ready to be hooked up. For a homeowner, a portable generator is the least expensive option to provide power during an emergency. These units run on exhaust-producing gasoline and require refilling every few hours. And they tend to be very loud. Noise levels of a midsize generator usually range from between 55 and 69 decibels.

Transfer Switch for Portable Generators

Homes using portable generators should have a transfer switch professionally installed. A transfer switch is installed next to a home's main electrical panel and connects to the panel's circuits during a power outage. This negates the need to run extension cords to each appliance and prevents electrical back feed. The transfer switch is run to an outside outlet that the generator connects to with a single extension cord. In an emergency situation where a transfer switch has not been installed, do not plug the generator into the main wiring of your home. Instead, use an extension cord to plug in only the appliances you need. This will help prevent back feed, which can damage your generator and appliances and possibly electrocute technicians working on nearby power lines.

Standby Generators

A standby backup generator is much more expensive than a portable generator. The benefits are that it turns on automatically, does not require frequent refueling and is much safer to use. A standby generator is tied directly into a house's electrical system and will turn on automatically if there is a power outage. It is fueled by natural gas directly from a home's gas system and can run for several days or even weeks without refueling. Most standby generators are installed inside an enclosure that greatly reduces noise levels. Standby generators are usually installed between the gas and electrical meter and should be at least 18 inches away from the house and a minimum of 5 feet from doors and windows.


A portable generator should always be operated in a well ventilated, dry area to avoid carbon monoxide poisoning and electrical shock.


Install a carbon-monoxide detector in the house near a window close to where the generator will operate.