How Long Does Solar Installation Take?
There are two very different answers to “how long does solar take?” The physical installation is fast - a couple of days. The whole process, from signing to switch-on, usually runs 1-3 months. Here’s where the time actually goes.
The two timelines
- Install day(s): 1-3 days of crew on your roof.
- Full project: typically 6-12 weeks start to finish.
The gap is paperwork and waiting on third parties - permits and the utility - not the labor. (Full sequence: the installation process.)
Typical timeline by step
| Step | Typical time |
|---|---|
| Site survey | a few days to schedule |
| Design & engineering | ~1-2 weeks |
| Permitting | 1-6 weeks (most variable) |
| Installation | 1-3 days |
| Inspection | a few days to 2 weeks |
| Utility interconnection & PTO | 2-6 weeks |
| Switch-on | same day as PTO |
Add it up and you land in the 1-3 month range for most homes.
What causes delays
- Permitting backlogs. Some city/county offices are slow; this is the #1 variable. See permits & inspections.
- Utility interconnection queues. Granting PTO can take weeks, and the system can’t legally run until it arrives.
- Roof or panel issues. A roof that needs repair first, or a main-panel upgrade, adds time. See roof types.
- HOA approval, weather, and equipment availability can each add days/weeks.
What you can do to speed it up
- Respond to your installer’s requests for documents quickly.
- Sort out any roof repairs or electrical panel upgrades early.
- Choose an installer experienced with your local building department - they know the process and submit clean plans. See how to choose an installer.
Bottom line
Plan for 1-3 months overall, even though crews are only on your roof for 1-3 days. The wait is mostly permits and utility PTO - outside your installer’s direct control. If a company promises “installed and running next week,” be skeptical: the utility and city set much of the pace.
Educational estimate only, current as of June 2026. Timelines vary widely by location, utility, and installer workload.