Technical Booklet R Access to and Use of Buildings·Page 32·4.23
Internal stairs as alternative means of vertical access
Internal stairs must be provided as an alternative means of vertical access alongside any lifting device chosen.
Whatever lifting device is chosen, internal stairs should also be provided as an alternative means of vertical access.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet R - Access to and Use of Buildings.pdf