holiday home vs summerhouse

holiday home

noun
  • A second home used for holidays. 

summerhouse

noun
  • A house owned not as a primary residence and used as vacation home during warm weather months of the year. 

  • An outbuilding in a garden where the owners can relax in warm weather. 

How often have the words holiday home and summerhouse occurred in a corpus of books? (source: Google Ngram Viewer )