Access to HE Diplomas are designed to prepare mature learners for higher education (HE). They have been specifically designed for people who may have little in the way of formal educational qualifications, but who bring to the course a variety of life and work experience, a desire to learn and a willingness to study. In addition to their main subjects, students have the opportunity to study literacy, numeracy and information technology. The St John's Centre also offers GCSE English and Maths. A supportive learning environment is provided by using a variety of methods, including lectures, workshops, laboratory sessions, tutorials, group work and private study.

In the past, students have progressed onto university courses in, biochemistry, physics, astrophysics, mathematics, environmental science, computation, chemical engineering and material science. It can also lead to careers in engineering (mechanical / chemical / civil) and physical sciences.