926.2 (B) Functional Features
The U.S. Copyright Office will not register purely functional elements of an architectural work, such as innovations in architectural engineering or construction techniques.
Example:
• Fulton Fowler designed a house with a solar-powered hot water heater and an earthquake-resistant bracing system. He filed an application to register each element of his design. The registration specialist may register the overall design as an architectural work if it is sufficiently original, but the specialist will ask the applicant to remove the references to the heater and bracing system.