Originally Posted by
rjque
I think a key consideration would be the transfer access from the Hibiya line to the Yamanote line. I found the map below online, but I'm not sure how old or accurate it is:
http://www.wakakoma.org/aj/map/etokyo01.pdf
This map says that Ebisu station requires the use of stairs.
Seems accurate to me. Komagome is a good example of a station which is accessible but only with assistance - becomes tricky late at night, as you do require the assistance you'll need to arrive something like 15 minutes before the last train to allow the employees to help you down to the ticket hall with an elevator that isn't in normal use (can't fully remember this bit as we were a bit p*ssed, there's an izakaya we really like here), and then they need to cordon off the escalators to turn it into a moving platform. The photo I posted a link to in the link above of the moving platform is at Komagome station.
What the map doesn't cover is the JR Yamanote line access. There may be stairs at the Ebisu Hibiya line exit but not at the Ebisu JR station entrance.*
*confirmed here:
http://www.wakakoma.org/aj/map/etokyo02.pdf