The lense you reference is for the older 4/3 system, not micro 4/3. It can work on the camera with an adapter, but will not work in a housing. For wide angle on m4/3 you should be looking at the m4/3 specific lenses which would be the olympus 9-18, the panasonic 7-14 or the panasonic 8mm fisheye. Zen makes ports for each.
Search on this forum as someone had to modify the epl3 housing to get one of the Zen ports to fit.
Note that the olympus housing for the epl3 only lists the 14-42 as being supported.
the oly housings for the epl1/2 would also support the 9-18 in the base housing. However, most people added the Zen port to get the full view which can not be achieved behind the flat port.