Enclosing an outdoor space that already has a roof

Hi!

I live in a house in Scarborough where I would like to enclose one of my existing carports with a wall of windows and make it part of my heated, indoor space. The existing carport is under the main house to the right of the front door, which is supported by concrete columns (see picture attached).

My understanding is that because a roof already exists, the walls would not have to bear any load. But I would expect that I still need some type of foundation?

Any ideas what the different types of foundations would cost? And would the existing concrete columns limit my options?

Thanks!