There may be other names, the one I know (from reading US fiction) is a **Porte cochere**

> [Definition of porte cochere][1] Merriam-Webster

> 1 :  a passageway through a building or screen wall designed to let
> vehicles pass from the street to an interior courtyard
> 
> 2 :  a roofed structure extending from the entrance of a building over
> an adjacent driveway and sheltering those getting in or out of
> vehicles

By way of further confirmation, a reverse image search on the OP's picture produces the same image captioned '[Port Cochere with detached garage behind][2]'.


  [1]: https://www.merriam-webster.com/dictionary/porte%20cochere
  [2]: https://www.google.com/search?hl=en&q=detached%20garage%20behind%20house&tbm=isch&imgil=aThBwrVldXTp6M%253A%253BHEdLYORrCju4dM%253Bhttps%25253A%25252F%25252Fwww.pinterest.com%25252Fmargaretbrose%25252Fcarports%25252F&source=iu&pf=m&tbs=simg:CAESogIJzg9brW1p26oalgILEKjU2AQaAggDDAsQsIynCBpiCmAIAxIo2xTZFNgU1hTcFOAU2hTdFN4U3xTpKuoq9jjIIe4q9TjfOOk46yroPhowha4AfHsl7za0QUvslm8bwJGscZV4k5WLbijCWFm1eyeNaPuwD7dcYzYukJGh8DfyIAQMCxCOrv4IGgoKCAgBEgSBm9ZGDAsQne3BCRqDAQoXCgVob3VzZdqliPYDCgoIL20vMDNqbTUKGgoIYnVpbGRpbmfapYj2AwoKCC9tLzBjZ2g0ChYKBHJvb2bapYj2AwoKCC9tLzA2aHlkChkKBmVzdGF0ZdqliPYDCwoJL20vMDM4dDhfChkKBnNpZGluZ9qliPYDCwoJL20vMDM3Y3l3DA&fir=aThBwrVldXTp6M%253A%252CHEdLYORrCju4dM%252C_&usg=__VZbAk7lXzFIGXbxQn--hdtEhwto%3D&biw=904&bih=586&ved=0ahUKEwiNjNPJ0LrUAhVICsAKHTYgA6kQyjcISw&ei=o8A_Wc2uNsiUgAa2wIzICg#imgrc=aThBwrVldXTp6M: