Returning to a childhood home in a dream often means you're processing something from that period of your life, or measuring how far you've come against where you started. If the house looks different from how you remember it, that gap is usually the point -- it reflects how much you've changed, not a flaw in your memory.
Planets are notably made unfortunate by these accidents, viz. Combustion, Retrogradation, Peregrination, Detriment and Fall. - William Lilly (1602.-1681.)