It wasn't a problem for us, but the bedroom is up two narrow, windy flights of stairs and the breakfast room is one more flight up, something to think about if you have large luggage or difficulty climbing stairs.
We had booked expecting a room in a B&B but we in fact had a little apartment above the proprietor's wife's ceramics gallery, with a comfortable bedroom, spacious bathroom, and our own private breakfast room on the floor above. We had a coffee maker and a fridge that was stocked with milk, juice, jam, ham and cheese, and each morning when we got up there was a basket with fresh bread outside our door, so we could enjoy a leisurely breakfast before heading out to enjoy Brussels. The location is great, close to the Grand Place and other sites but far enough away that it didn't feel touristy. The proprietor was warm and welcoming and went out of his way to make sure we had something to have for breakfast on our last day, when we had to leave really early for the airport. We recommend B&B Taptoe enthusiastically.