Hedgehog houses

hello everyone, 

I'm new here, last year i had a hedgehog that visited all through the summer, so I decided to get a hedgehog house & it did hibernate in the house over winter.

Thus year I have doubled my numbers & have had 2 hedgehogs over the summer, so I’ve decided to get an extra hedgehog house.

my question is do I put the houses next to each other or shall I place the new house away from the existing house I bought last year. 

Many thanks