Not unless you can run a cable (or attach a pair of outdoor APs) up the side of the building and add an access point. Wireless extenders are pretty useless.
It depends on how good of a friend it is and if you want to spend some money. You could get a nice pair of AC routers (ASUS RT-AC68U or Netgear R7000), one for him and the second for you in media bridge mode. That works pretty well over a fair distance when you make an AC bridge between two of the same model. But then you may end up using more of his bandwidth than he would like.
The other good option is to get your own Internet service so that you can get a good connection yourself.