A work colleague has recently graduated with a 2:1 in Fine Art from DMU. She had no paper qualifications but, as a mature student, had completed a one year, recognised foundation course at a local college and also had to produce a portfolio showing the range of her work and how she had developed during the foundation course.
It was a very intensive degree course, requiring a lot of time spent 'in studio', and included setting up exhibitions and finding commissions among other tasks, as well as an end-of-course show.
If she had wanted to teach, then she would have needed GCSE or equivalent in Maths, English and Science, and would have needed to complete a specialist, one year PGCE. Again, she'd have needed to produce a good portfolio.
There is also the four year route, which combines the subject degree with the teaching certificate, but I know virtually zero about those.
Sorry, LoftyLottie, but the OU does not offer art-based degrees - only in art history, which is very different, although art history is part of fine art study. You can, however, earn transferable degree credits via the Open College of the Arts, which is a separate organisation and which offers a number of courses in art, design and media.