Here is what was pointed to in another post I made here:
Class E:
https://www.faa.gov/documentLibrary/media/Order/JO_7400.11D.pdf
Generally, if the airspace is not Class A, Class B, Class C, or Class D, and it is controlled
airspace, it is Class E airspace. Class E airspace extends upward from either the surface or a
designated altitude to the overlying or adjacent controlled airspace. When designated as a
surface area, the airspace will be configured to contain all instrument procedures. Also in this
class are Federal airways, airspace beginning at either 700 or 1,200 feet above ground level used
to transition to/from the terminal or enroute environment, and enroute domestic and offshore
airspace areas designated below 18,000 feet MSL. Class E airspace does not include the airspace
18,000 feet MSL or above.
I was led to believe that Class E is from the surface unless that airspace is marked by lines and/or vignette circles.