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Services
Structural Letters & Electrical Stamps
Roof Letter & Pages Stamped
This cost effective, fundamental letter is what the majority of AHJs require. It states that a roof can handle the additional loads of the solar system, and includes design stamps.
Installation Letter & Pages Stamped
This letter includes the roof only letter, additional calculations to determine the attachment separation, as well as design stamps.
Installation Letter & Pages Stamped + Electrical Stamp
In addition to the installation letter, this service consists of a thorough review and stamp of the entire design, including electrical. The precise review and stamp of the electrical design is performed by an in-house licensed electrical engineer.
Services
Our benefits
Zero AHJ Rejection Guarantee
Solar Letters leverages Castillo Engineering’s experience since 1998, which has an industry leading 99.9% first time approval rating. If our letter receives an AHJ rejection, we will gladly issue you a full credit.
Fastest Turnaround Guarantee
We pride ourselves on our advanced automation, as we know how important it is to receive your stamps within the hour. If you do not receive your letter by the next business day or less, you will receive a full credit.
Lowest Price Guarantee
We will match or beat any documented competitor price. We also offer volume discounts through our Permit Partner Program.
Post-installation
Post-Installation Letter (PIL)
After the installation is complete, this letter verifies that site observations have been performed by an in-house engineer. It states that the system has been installed per the permitted plans.
Who we support
Small to mid-size residential installers
Large national residential installers
International design
firms
CAD Design + Stamps
Through our proprietary CAD designs, we optimize installations while reducing cost. Our approach guarantees high accuracy and the lowest bill of materials. We also include PE stamping for free.
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