Home Generator Installation Cost

Portable Versus Standby: Two Very Different Projects

A portable generator is wheeled out during an outage, fueled with gasoline, and connected to select circuits through extension cords or a manual transfer switch. It's the cheaper option and requires no permanent installation. A standby generator is permanently wired to your electrical panel, fueled by a dedicated natural gas or propane line, and starts automatically within seconds of a power outage. It's a real electrical and gas-line project, not an appliance purchase.

What the Transfer Switch Actually Does, and Why You Need One

A transfer switch electrically isolates your home from the utility grid before the generator powers it, which is what keeps your generator from back-feeding electricity into the grid and electrocuting a utility lineman working on a downed line during the outage. This isn't a corner worth cutting. Most jurisdictions require a licensed electrician to install it, and running a generator without one, using improvised extension cord setups, is a genuine safety hazard.

• Standby generators need an annual service, similar to a furnace, including an oil change and a load test, to make sure they'll actually start when the power goes out.
• Sizing a standby unit too small means it'll shed circuits (like the AC) automatically during heavy load. Sizing it correctly for your actual panel usually requires an electrician's load calculation, not a guess based on square footage alone.

Natural Gas Versus Propane as the Fuel Source

Natural gas standby generators tap directly into an existing gas utility line, meaning fuel supply is essentially unlimited as long as the gas service stays on, which is a real advantage during an extended outage. Propane requires an on-site tank, either an existing tank shared with other appliances or a new dedicated one, and running time is capped by tank capacity, though propane remains a solid option for homes without natural gas service available. Homes without natural gas access typically need to budget for a propane tank purchase or lease as part of the total project cost, on top of the generator and installation itself.

Placement Rules and Noise Considerations

Most manufacturers and local codes require standby generators to sit a minimum distance, often 18 to 60 inches depending on the model, from windows, doors, and combustible walls, both for ventilation and to keep exhaust away from living spaces. Standby units also run at a noticeable noise level during operation and during the brief weekly self-test cycle most owners program, so placement relative to bedroom windows and neighboring property lines is worth considering during planning, not after the concrete pad is already poured.