A mullion wall is a structural system in which the load of the floor slab is taken by prefabricated panels around the perimeter. Visually the effect is similar to the stone mullioned windows of Perpendicular Gothic or Elizabethan architecture.
The technology was devised by George Grenfell Baines and the engineer Felix Samuely in order to cope with material shortages at the Thomas Linacre School, Wigan (1952) and refined at the Shell Offices, Stanlow (1956), the Derby Colleges of Technology and Art (1956–64). and Manchester University Humanities Building (1961–67) 
- Architects’ Journal (1960), “Technical College”, Architects’ Journal, (March 17) pp 441-448.
- Bill White (1987), The Spirit Of BDP, p 49.