Section R311.2: Exit door — at least one exit door, min 32 in clear width, max 36 in landing to grade. Section R311.3: Floors and landings — landing at each door min 36 in in direction of travel, max 1.5 in threshold height. Section R311.4: Hallways — min 36 in width. Section R311.7: Stairways — min 36 in width, max riser 7.75 in, min tread 10 in, max 4-3/8 in rise nosing radius. Handrails: 34-38 in height, graspable profile 1.25-2 in. Guards: min 36 in height at stairs, 36 in at other locations. Section R311.7.5: Stairway headroom — min 6 ft 8 in. Section R310: Emergency escape and rescue openings — every sleeping room and basement habitable room. Min 5.7 sf net clear, min 20 in wide, min 24 in high. Sill height max 44 in above floor. Window wells for below-grade: min 9 sf, 36 in horizontal projection.