General Requirements

Where Required (R310.1)

  • Basements, habitable attics, and every sleeping room must have at least one operable emergency escape and rescue opening
  • Where basements contain one or more sleeping rooms: each sleeping room requires an opening
  • Openings must lead directly into a public way, or to a yard or court that opens to a public way

Exception: Storm shelters and basements used only for mechanical equipment with total floor area not exceeding 200 square feet (R310.1)

Sizing Requirements

Minimum Net Clear Opening Area (R310.2.1)

  • Standard requirement: 5.7 square feet
  • Grade floor or below grade openings: 5.0 square feet

Minimum Net Clear Opening Height (R310.2.1)

  • 24 inches

Minimum Net Clear Opening Width (R310.2.1)

  • 20 inches

Placement & Positioning

Sill Height (R310.2.2)

  • Maximum sill height: 44 inches above the floor
  • When sill height is below grade: window well required per Section R310.2.3

Location (R310.1)

  • Must open directly into a public way, or to a yard or court that opens to a public way

Operability

Operation Requirements (R310.1.1)

  • Must be operational from inside the room
  • No keys, tools, or special knowledge required for operation
  • Net clear opening dimensions must be obtained by normal operation from the inside
  • Window opening control devices complying with ASTM F 2090 are permitted

Window Wells

When Required (R310.2.2)

  • Required when window sill height is below grade

Minimum Dimensions (R310.2.3)

  • Minimum horizontal area: 9 square feet
  • Minimum horizontal projection: 36 inches
  • Minimum width: 36 inches
  • Must allow the emergency escape opening to be fully opened

Exception: Ladders or steps may encroach a maximum of 6 inches into required dimensions

Ladder/Step Requirements (R310.2.3.1)

  • Required when: Window well vertical depth exceeds 44 inches
  • Must be permanently affixed
  • Must be usable with window in fully open position
  • Minimum inside width: 12 inches
  • Minimum projection from wall: 3 inches
  • Maximum vertical spacing: 18 inches on center

Drainage (R310.2.3.2)

  • Window wells must be designed for proper drainage by connecting to building's foundation drainage system (Section R405.1) or by approved alternative method

Exception: Drainage not required where foundation is on well-drained soil or sand-gravel mixture soils (Group I Soils per Table R405.1)

Emergency Escape and Rescue Doors

General Requirements (R310.3)

  • Where a door serves as required emergency escape and rescue opening, it may be side-hinged or slider
  • When opening is below adjacent ground elevation: bulkhead enclosure required

Minimum Door Opening Size (R310.3.1)

  • Minimum net clear height opening must comply with Section R310.2.1

Bulkhead Enclosures (R310.3.2)

  • Must provide direct access from basement
  • Must provide minimum net clear opening equal to the door in fully open position

Drainage (R310.3.2.1)

  • Bulkhead enclosures must be designed for proper drainage by connecting to building's foundation drainage system (Section R405.1) or by approved alternative method

Exception: Drainage not required where foundation is on well-drained soil or sand-gravel mixture soils (Group I Soils per Table R405.1)

Bar, Grilles, Covers & Screens

Permitted With Conditions (R310.4)

  • May be placed over emergency escape openings, bulkhead enclosures, or window wells
  • Must maintain minimum net clear opening sizes (per R310.1.1 through R310.2.3)
  • Must be releasable or removable from inside
  • No keys, tools, special knowledge, or excessive force required
  • Force required must not exceed that needed for normal operation of the opening

Special Conditions

Under Decks and Porches (R310.2.4)

  • Emergency escape and rescue openings are permitted under decks and porches when:
    • Deck location allows opening to be fully opened
    • Provides a path at least 36 inches in height to a yard or court

Replacement Windows (R310.2.5)

  • Replacement windows are exempt from maximum sill height requirements when:
    • Window is manufacturer's largest standard size that fits existing frame or rough opening
    • Window is same operating style as existing, or provides equal or greater opening area
    • Replacement is not part of a change of occupancy

Dwelling Additions (R310.5)

  • New sleeping rooms in additions require emergency escape and rescue openings
  • New basements in additions require emergency escape and rescue openings

Exceptions:

  • Not required in new basement containing sleeping room with its own opening
  • Not required in new basement when existing basement has opening accessible from new basement

Alterations or Repairs of Existing Basements (R310.6)

  • Emergency escape and rescue opening not required for alterations or repairs

Exception: New sleeping rooms created in existing basement must have emergency escape and rescue openings per R310.1

Note: Always verify current code requirements with local building officials, as local amendments may apply.