I have a 9' X 12' screen porch attached to a 1950's style cape that I'm enclosing. The porch is located on the side of the house, flush with the front. When complete, it will appear that the house has been lengthed by 9'.
The house is aluminum sided. The new vinyl sided matches the aluminum in color (white) and reveal (4"). No problems there.
The issue is mating the aluminum corner channel with vinyl j-channel. Since this is the front of the house and I am not an aluminum siding professional, I do not want to risk damage to siding by removing the corner piece.
if the framing is matched to the existing then I would strip the whole side of the house and reside it with the vinyl. or you could pull off the corner and install an H channel and run your siding into that. being a contractor I would go the first route, it would look much better. BOB