So you have taken out a wall where there were hardwood floors on either side. You know you have to fill the gap with something, but what?The first realisation is that even if both sides are floored with the same wood installed at the same time, the boards on one side will never line up with the boards on the other side. You cannot just continue the boards across the new room. I think that the best solution I have seen is to trim both sides straight and insert new boards perpendicular to the old ones, often going for a totally contrasting wood or contrasting colour since you simply cannot match the...