Final answer:
The minimum stairway width above handrails varies according to building codes, which change over time and by location. Older guidelines suggest 5 diameters wide while newer standards recommend up to 8 diameters wide.
Step-by-step explanation:
The minimum width of a stairway above handrails is not specified with the provided information. However, building codes typically dictate these measurements to ensure safety and accessibility. Two common reference points are an older "rule of thumb" that suggests a stairway should be 5 handrail diameters wide and 7-8 diameters deep, and more recent guidance that recommends up to 8 diameters wide and 15 diameters deep. It's essential to consult current building codes or a construction expert for precise regulations as these can vary by location and over time.