FTP - user to upload file to different user's directory

I installed vsftpd and configured SFTP. I have a standard user who is named, let's say, user1 with all perms. I don't want to give the password to my friend. I only want him to access a specific directory to upload files so server can run them. The file place is : /home/user1/upload I created a user, with no shell login, named user1ftp. I changed the user home location to /home/user1/upload so when he logs in, he directly logs into the upload directory. He can upload and delete files in it. The problem is that when he uploads a file, the server cannot run it. His files' permission are: **rw-r--r--** I need to make sure that when he uploads a file, the permissions are **rwxrwxr-x** These users are members of the same group. How can I do that?