Web hosting public_html folder missing?

Here`s a question re public_html folder missing... not entirely SEO related, hope its ok for this community forum, if not please advise a suitable community to hook up with. I have to rebuild a new clients website on a wordpress platform. The old website was built in just basic asp.net code. I have ftp login details to their website. When l logon they only have a wwwroot folder and no public_html folder. Not sure if this is the norm for asp sites. How would I install wordpress in this instance please? do I not need a public_html folder any suggestions? Or should I be asking how to I create a public_html folder with the correct permissions etc. I believe it is quite a tricky set up to get this particular folder right? Look forward to any useful replies. Thanks. Cheers.