Posted By John Ridd With storage to shelves at the heights you state I guess (hope) you're using appropriate step ladders - surely, they will define your aisle width (plus sufficient space for passing?). Other factors have to be the size of your archive boxes (usually far to large in my experience - people just fill them and make the handling task a nightmare (put limits on the weight)), and the size (anthropometry) of your archive staff. Ergonomics guidance says aisle widths relate to hip width (females) or shoulder breadth (males)plus allowances for clothing and/or items carried. There are many standards that might help you and which deal width access and clearance (American Military Stds, UK Def Stds, German DIN stds etc.) Steve Pheasant also quotes (in a BSI book - 'Ergonomics : Standards and Guidelines for designers') International Stds (Annex to ISO 3055)for circulation and access in buildings and for kitchen design that could, I believe, be usefully applied to your situation.