Switching to a new dog house

Question
I have a 4 yr. old Terrier/Springer Span. Mix. By the time he was 2 he had chewed up his dog house badly, and he had grown a bit since I bought the house #1.  So, I bought house #2 (slightly bigger) but he refused to sleep inside it.  It rained hard one night and he stood outside in the rain.  I felt bad and so I returned house #1 to him.  For the past 2 yrs. the two houses have been sitting by each other.  I started putting his food in house #2 to keep it dry and give him more room in house #1, but I still feel like he should move into the slightly bigger house (#2). It is not as chewed up as #1 and it has a door for weather purposes.  I recently got a new pup and purchased a new house for him (igloo).  I think it is a good house and I would like to buy another one for my 4 yr. old, but how do I get him to live in another house (house #2 or a new one)?

Answer
The igloo type houses are nice. I like them, too. It >>is<< a bit strange that your older dog prefers the old house and will not go into the new one that you got for him. Are they both the same style? Will the old one fit >>inside<< the new one? That might be one way you can get him to start using the new one, if you can put even just the bottom half (I'm assuming it comes in two halves) inside the new house for a while, until he gets used to going into the new house, and then try removing the old one and see if he continues to use the newer house.

It could be that he doesn't like the door on the new house, or doesn't understand that he can go through it. Have you tried removing the door, or pinning it up so that the opening is readily accessible? You may have to do that for a while. Is the door flap clear? Is it heavy?

Just throwing out ideas.