Two different clocks

It helps to separate "how long is a crew physically at my house" from "how long until the system is signed off and running." The physical installation — pad placement, wiring, fuel connection, transfer switch — is often done in a day or two. Permitting and equipment lead times are what stretch the overall timeline to several weeks.

Where the time actually goes

After a signed contract, permits typically need to be filed and approved by your local authority before work can begin — this step's timeline is set by your jurisdiction, not your installer.

Equipment availability also plays a role; popular sizes are often in stock, but certain models or configurations can have longer lead times.

Once permits are in hand, physical installation usually happens within a day or two, followed by scheduling the final code inspection — which depends on your local inspector's calendar.

Timing around storm season

Demand for installers and equipment both climb ahead of storm season in outage-prone regions, which can stretch lead times right when people most want a faster turnaround. Starting the process in the off-season — before demand spikes — is one of the more reliable ways to avoid a multi-month wait.