"it is random. It has to do with the way that a book is printed. Books are printed 32 pages at a time, after which the sheet of 32 pages (16 on a side, so each page is run through the printed machine at least twice) is folded and trimmend so it can sewn or glued together into the format you know and love as a book. Now, to add another color to the text, the pages need to be run through the printer an additional time for each color. This means that they have to try and match up on the printing machine's plate where the blue house will appear within the alrady printed black text. If you look, you'll notice that often the word house has more space around it than really necessary. This was most likely done by the printer to give them a larger area to try and fit the word. That's just my more than 2 cents."
I have a copy of the red edition, and house is printed in grey, and the word is not out of place. thus, it must not be intentional.