Posted By John Webster A single escape route is quite common, and perfectly acceptable if other conditions are met. Depending upon the type of building and layout etc, there is a maximum distance to a safe escape route which must not be exceeded and is contained in building regs. The safe escape route will be constructed in such a way that it is virtually fireproof, for example it will have fire doors (1 hour resistant, self closing) at top and bottom of the stairwell and at any intermediate levels. The staircase will be steel or concrete, or, if wood, lined with fire retardant material etc If in doubt, contact your local fire safety officer at the fire brigade. As for toilets, you do not have to provide access for disabled people if your upstairs office is not physically providing any service to the public. However, be aware that should a disabled person apply for a job in that office, you would have to treat them equally and, if selected, be prepared to make reasonable adjustments to accommodate their disability.