Cost ranges for built-in generators typically span from basic packages to full turnkey systems. A modest setup with natural gas and a mid sized output might run around $9,000 to $12,000 installed, while high performance modes with larger outputs and lighting controls can exceed. Quick answer: In 2025, a typical whole house generator installation costs $6,000–$30,000, driven by generator size (kW), brand, transfer switch, electrical upgrades, fuel line/permits, and local labor rates. In comparison, portable. Most home generators cost between $400 and $23,000+, depending on the type, size, and installation. Trusted Home Depot partner for more than 15 years. This will power a few emergency systems but not an entire home, and might be manually operated.