13VAC5-63-434. Chapter 8 Additions.
Replace Chapter 8 of the IEBC with the following:
1. Section 801 General.
801.1 Scope. Additions to any building or structure shall comply with the requirements of the VCC 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. Where a fire wall that complies with Section 706 of the VCC is provided between the addition and the existing building, the addition shall be considered a separate building.
Note: Where one or more newly constructed fire walls that comply with Section 706 of the VCC are provided between an existing building, structure, or portions thereof and a new building, this chapter is not applicable per Section 102.2.3.
801.2 Creation or extension of nonconformity. 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. Alterations to the existing building or structure shall be made so that the existing building or structure, together with the addition, are no less conforming to the provisions of the VCC than the existing building or structure was prior to the addition.
801.3 Other work. 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 this code.
2. Section 802 Heights and Areas.
802.1 Height limitations. No addition shall increase the height of an existing building beyond that permitted under the applicable provisions of Chapter 5 of the VCC for new buildings.
802.2 Area limitations. No addition shall increase the area of an existing building beyond that permitted under the applicable provisions of Chapter 5 of the VCC for new buildings unless fire separation as required by the VCC is provided.
Exceptions: The following shall be permitted beyond that permitted by the VCC.
1. In-filling of floor openings such as elevator and exit stairway shafts.
2. The addition of nonoccupiable spaces such as elevators, stairs, and vestibules.
802.3 Fire protection systems. Existing fire areas increased by the addition shall comply with Chapter 9 of the VCC.
3. Section 803 Structural.
803.1 Compliance with the VCC. Additions to existing buildings or structures are new construction and shall comply with the VCC.
803.2 Existing structural elements carrying gravity load. Any existing gravity load-carrying structural element for which an addition and its related alterations cause an increase in design gravity load of more than 5.0% shall be strengthened, supplemented, replaced, or otherwise altered as needed to carry the increased gravity load required by the VCC for new structures. Any existing gravity load-carrying structural element whose gravity load-carrying capacity is decreased shall be considered an altered element subject to the requirements of Section 603.7.3. Any existing element that will form part of the lateral load path for any part of the addition shall be considered an existing lateral load-carrying structural element subject to the requirements of Section 803.3.
Exception: Buildings of Group R occupancy with no more than five dwelling units 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 VCC or the provisions of the International Residential Code.
803.2.1 Design live load. Where the addition does not result in increased design live load, existing gravity load-carrying structural elements shall be permitted to be evaluated and designed for live loads approved prior to the addition. If the approved live load is less than that required by Section 1607 of the VCC, the area designed for the nonconforming live load shall be posted with placards of approved design indicating the approved live load. Where the addition does result in increased design live load, the live load required by Section 1607 of the VCC shall be used.
803.3 Existing structural elements carrying lateral load. 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 be shown to meet the requirements of Sections 1609 and 1613 of the VCC. For purposes of this section, compliance with ASCE 41, using a Tier 3 procedure and the two-level performance objective in Table 305.2.1 for the applicable risk category, shall be deemed to meet the requirements of Section 1613.
Exceptions:
1. Any existing lateral load-carrying structural element whose demand-capacity ratio with the addition considered is not more than 10% greater than its demand-capacity ratio with the addition ignored shall be permitted to remain unaltered. 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. For purposes of calculating demand-capacity ratios, the demand shall consider applicable load combinations involving VCC-level seismic forces in accordance with Section 305.2.1.
2. 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 VCC or the provisions of the International Residential Code.
3. Buildings in which the increase in the demand-capacity ratio is due entirely to the addition of rooftop-supported mechanical equipment individually having an operating weight less than 400 pounds (181.4 kg) and where the total additional weight of all rooftop equipment placed after initial construction of the building is less than 10% of the roof dead load. For the purposes of this exception, "roof" shall mean the roof level above a particular story.
803.4 Voluntary addition of structural elements to improve the lateral force-resisting system. Voluntary addition of structural elements to improve the lateral force-resisting system of an existing building shall comply with Section 603.7.5.
803.5 Snow drift loads. Any structural element of an existing building subject to additional loads from the effects of snow drift as a result of an addition shall comply with the VCC.
Exceptions:
1. Structural elements whose stress is not increased by more than 5.0%.
2. Buildings of Group R occupancy with no more than five dwelling units 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 VCC or the provisions of the International Residential Code.
4. Section 804 Flood Hazard Areas.
804.1 Flood hazard areas. 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. 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.
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:
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. 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.
5. Section 805 Energy Conservation.
805.1 General. Additions to an existing building or portion thereof shall conform to the provisions of the VECC as those provisions relate to new construction without requiring the unaltered portion of the existing building to comply with the VECC. Additions shall not overload existing building systems. An addition shall be deemed to comply with the VECC if the addition alone complies or if the existing building and addition comply with the VECC as a single building.
805.2 Residential compliance. Residential additions shall comply with Section 805.2.1 or 805.2.2.
805.2.1 Prescriptive compliance. Additions shall comply with Sections 805.2.1.1 through 805.2.1.4.
805.2.1.1 Building envelope. New building envelope assemblies that are part of the addition shall comply with Sections R402.1, R402.2, R402.3.1 through R402.3.5, and R402.4 of the VECC.
Exception: The building envelope of the addition shall be permitted to comply through a Total UA analysis, as determined in Section R402.1.5 of the VECC, where the existing building and the addition and any alterations that are part of the project is less than or equal to the Total UA generated for the existing building.
805.2.1.2 Heating and cooling systems. New heating, cooling, and duct systems that are part of the addition shall comply with Section R403 of the VECC.
805.2.1.3 Service hot water systems. New service hot water systems that are part of the addition shall comply with Section R403.4 of the VECC.
805.2.1.4 Lighting. New lighting systems that are part of the addition shall comply with Section R404.1 of the VECC.
805.2.2 Performance compliance. The addition shall comply with the simulated performance alternative where the annual energy cost or energy use of the addition and the existing building and any alterations that are part of the project is less than or equal to the annual energy cost of the existing building when modeled in accordance with Section R405 of the VECC.
805.3 Commercial Compliance. Commercial additions shall comply with Section 805.3.1 or 805.3.2.
Exception: Commercial additions complying with ANSI/ASHRAE/IESNA 90.1.805.3.1 Prescriptive compliance. Additions shall comply with Sections C402, C403, C404, and C405 of the VECC.
805.3.2 Performance compliance. The addition shall comply with the simulated performance alternative where the annual energy cost or energy use of the addition and the existing building and any alterations that are part of the project is less than or equal to the annual energy cost or use of the existing building when modeled in accordance with Section C407 of the VECC.
Statutory Authority
§ 36-98 of the Code of Virginia.
Historical Notes
Derived from Virginia Register Volume 34, Issue 18, eff. September 4, 2018; amended, Virginia Register Volume 35, Issue 3, eff. November 1, 2018; Volume 37, Issue 14, eff. July 1, 2021; Volume 40, Issue 9, eff. January 18, 2024.