I don't think it's a good idea, you will have to build into your prices the time you are there in their home, which will be longer than if they came to you, you would have to have a minimum charge, otherwise you could going to see a 10x8 photo to be framed
you give them a price, "ho I think about it and give you a ring" so you end up going back to fetch the 10x8 , go back to the workshop, frame it, then deliver it, could be 6 car journeys. Even if you get the go ahead on your first visit, it's still going to be 4 car trips.
Better option would be as another forum member does, have market stall, frame some pictures up to sale, use old calenders, books etc, have them on the stall to attract customers, and have you moulding/mountcard samples, along with some signs up regarding custom framing,. Just do one or two markets a week, then the rest of the time you can be framing.