ADOPTS WITH AMENDMENTS:

International Existing Building Code 2018 (IEBC 2018)

Heads up: There are no amended sections in this chapter.

User note:

About this chapter: Chapter 11 provides the requirements for additions, which correlate to the code requirements for new construction. There are, however, some exceptions that are specifically stated within this chapter. An "Addition" is defined in Chapter 2 as "an extension or increase in the floor area, number of stories or height of a building or structure." Chapter 11 contains the minimum requirements for an addition that is not separated from the existing building by a fire wall.

An addition to a building or structure shall comply with the International Codes as adopted for new construction without requiring the existing building or structure to comply with any requirements of those codes or of these provisions, except as required by this chapter. Where an addition impacts the existing building or structure, that portion shall comply with this code.
An addition shall not create or extend any nonconformity in the existing building to which the addition is being made with regard to accessibility, structural strength, fire safety, means of egress, or the capacity of mechanical, plumbing, or electrical systems.

Any repair or alteration work within an existing building to which an addition is being made shall comply with the applicable requirements for the work as classified in Chapter 6.

An addition shall not increase the height of an existing building beyond that permitted under the applicable provisions of Chapter 5 of the International Building Code for new buildings.

An addition shall not increase the area of an existing building beyond that permitted under the applicable provisions of Chapter 5 of the International Building Code for new buildings unless fire separation as required by the International Building Code is provided.

Exception: In-filling of floor openings and nonoccupiable appendages such as elevator and exit stairway shafts shall be permitted beyond that permitted by the International Building Code.

Existing fire areas increased by the addition shall comply with Chapter 9 of the International Building Code.

[BS] 1103.1 Additional Gravity Loads

AMENDMENT
This section has been amended at the state or city level.
Any existing gravity load-carrying structural element for which an addition and its related alterations cause an increase in design dead, live, or snow load, including snow drift effects, that increases the demand-capacity ratio to more than 105 percent shall be replaced or altered as needed to carry the gravity loads required by the International Building Code for new structures. The evaluation of demand-capacity ratios and calculation of design gravity loads, forces, and capacities shall account for the cumulative effects of additions and alterations since original construction. Any existing gravity load-carrying structural element whose gravity load-carrying capacity is decreased as part of the addition and its related alterations shall be considered to be an altered element subject to the requirements of Section 806.2. Any existing element that will form part of the lateral load path for any part of the addition shall be considered to be an existing lateral load-carrying structural element subject to the requirements of Section 1103.3.
Exception: Buildings of Group R occupancy with not more than five dwelling units or sleeping units used solely for residential purposes where the existing building and the addition together comply with the conventional light-frame construction methods of the International Building Code or the provisions of the International Residential Code.

[BS] 1103.2 Lateral Force-Resisting System

AMENDMENT
This section has been amended at the state or city level.
Where the addition is structurally independent of the existing structure, existing lateral load-carrying structural elements shall be permitted to remain unaltered. Where the addition is not structurally independent of the existing structure, the existing structure and its addition acting together as a single structure shall meet the requirements of Sections 1609and 1613 of the International Building Code using full seismic forces.
Exceptions:
  1. Buildings of Group R occupancy with no more than five dwelling or sleeping units used solely for residential purposes where the existing building and the addition comply with the conventional light-frame construction methods of the IBC.
  2. Any existing lateral load-carrying structural element for which an addition causes an increase in demand-capacity ratio to no more than 110 percent shall be permitted to remain unaltered. For purposes of calculating demand-capacity ratios, the demand shall consider applicable load combinations with design lateral loads or forces in accordance with IBC Section 1609. For purposes of this exception, comparisons of demand-capacity ratios and calculation of design lateral loads, forces, and capacities shall account for the cumulative effects of additions and alterations since original construction.

Additions and foundations in flood hazard areas shall comply with the following requirements:

  1. For horizontal additions that are structurally interconnected to the existing building:

    1. 1.1. If the addition and all other proposed work, when combined, constitute substantial improvement, the existing building and the addition shall comply with Section 1612 of the International Building Code, or Section R322 of the International Residential Code, as applicable.
    2. 1.2. If the addition constitutes substantial improvement, the existing building and the addition shall comply with Section 1612 of the International Building Code, or Section R322 of the International Residential Code, as applicable.
  2. For horizontal additions that are not structurally interconnected to the existing building:

    1. 2.1. The addition shall comply with Section 1612 of the International Building Code, or Section R322 of the International Residential Code, as applicable.
    2. 2.2. If the addition and all other proposed work, when combined, constitute substantial improvement, the existing building and the addition shall comply with Section 1612 of the International Building Code, or Section R322 of the International Residential Code, as applicable.
  3. For vertical additions and all other proposed work that, when combined, constitute substantial improvement, the existing building shall comply with Section 1612 of the International Building Code, or Section R322 of the International Residential Code, as applicable.
  4. For a raised or extended foundation, if the foundation work and all other proposed work, when combined, constitute substantial improvement, the existing building shall comply with Section 1612 of the International Building Code, or Section R322 of the International Residential Code, as applicable.
  5. For a new foundation or replacement foundation, the foundation shall comply with Section 1612 of the International Building Code or Section R322 of the International Residential Code, as applicable.
Where an addition is made to a building or structure of a Group R or I-1 occupancy, the existing building shall be provided with smoke alarms as required by Section 1103.8 of the International Fire Code or Section R314 of the International Residential Code as applicable.

1105.1 Carbon Monoxide Alarms in Existing Portions of a Building

AMENDMENT
This section has been amended at the state or city level.
Where an addition is made to a building or structure of a Group I-1, I-2, I-4, or R occupancy, the existing building shall be equipped with carbon monoxide alarms in accordance with IBC section 915.

1106.1 Addition to a Group E Occupancy

AMENDMENT
This section has been amended at the state or city level.
Where an addition with an occupant load of 50 or more is made to an existing Group E occupancy, the addition shall have a storm shelter constructed in accordance with ICC 500 in the following counties: Anoka, Benton, Blue Earth, Brown, Carver, Chippewa, Chisago, Cottonwood, Dakota, Dodge, Faribault, Fillmore, Freeborn, Goodhue, Hennepin, Houston, Isanti, Jackson, Kandiyohi, LeSueur, Lincoln, Lyon, Martin, McLeod, Meeker, Murray, Nicollet, Nobles, Olmsted, Pipestone, Ramsey, Redwood, Renville, Rice, Rock, Scott, Sherburne, Sibley, Steele, Stearns, Swift, Wabasha, Waseca, Washington, Watonwan, Winona, Wright, and Yellow Medicine.
Exceptions:
  1. Group E day care facilities.
  2. Group E occupancies accessory to places of religious worship.
  3. Additions meeting the requirements for shelter design in ICC 500.

The required occupant capacity of the storm shelter shall include all buildings on the site, and shall be the greater of the following:

  1. The total occupant load of the classrooms, vocational rooms and offices in the Group E occupancy.
  2. The occupant load of any indoor assembly space that is associated with the Group E occupancy.

Exceptions:

  1. Where an addition is being added on an existing Group E site, and where the addition is not of sufficient size to accommodate the required occupant capacity of the storm shelter for all of the buildings on-site, the storm shelter shall at a minimum accommodate the required capacity for the addition.
  2. Where approved by the code official, the required occupant capacity of the shelter shall be permitted to be reduced by the occupant capacity of any existing storm shelters on the site.
Storm shelters shall be located within the buildings they serve, or shall be located where the maximum distance of travel from not fewer than one exterior door of each building to a door of the shelter serving that building does not exceed 1,000 feet (305 m).
Additions to existing buildings shall conform to the energy requirements of the International Energy Conservation Code or International Residential Code as they relate to new construction.
UpCodes Premium
Leverage the most sophisticated code compliance platform.
TRY FREE FOR TWO WEEKS VISIT PRICING