Adopts With Amendments
Chapter 5
Existing Buildings
International Energy Conservation Code 2021
[F] 501.1 Scope
Section 501.1 — Scope. This section establishes the scope, applicability, and administrative provisions for enforcement of this code. Refer to the official code text for complete requirements.
[F] 501.1.1 Commercial Scope
Section 501.1.1 — Commercial Scope. This section establishes the scope, applicability, and administrative provisions for enforcement of this code. Refer to the official code text for complete requirements.
[F] 502.1 General
Section 502.1 — General. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] 502.1.1 Commercial Envelope
Section 502.1.1 — Commercial Envelope. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] 503.1 Alterations
Section 503.1 — Alterations. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] 503.1.1 Commercial HVAC
Section 503.1.1 — Commercial HVAC. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] 504.1 Repairs
Section 504.1 — Repairs. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] 504.1.1 Commercial Water Heating
Section 504.1.1 — Commercial Water Heating. This section covers plumbing system requirements. Specific sizing, materials, and installation methods are in the official code text. Refer to the official code text for complete requirements.
[F] 505.1 Change of Occupancy
Section 505.1 — Change of Occupancy. This section establishes occupancy classification and use requirements that determine applicable building code provisions. Refer to the official code text for complete requirements.
[F] 505.1.1 Commercial Lighting
Section 505.1.1 — Commercial Lighting. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C401.1 Scope — Commercial Energy Efficiency
Section C401.1 — Scope — Commercial Energy Efficiency. This section establishes the scope, applicability, and administrative provisions for enforcement of this code. Refer to the official code text for complete requirements.
[F] C402.1 Building Envelope — Commercial
Section C402.1 — Building Envelope — Commercial. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] C402.2 Roof Assembly Insulation
Section C402.2 — Roof Assembly Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] C402.4 Fenestration — Commercial
Section C402.4 — Fenestration — Commercial. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C402.5 Air Leakage — Commercial
Section C402.5 — Air Leakage — Commercial. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C403.1 HVAC — Commercial General
Section C403.1 — HVAC — Commercial General. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] C403.3 Economizers — Commercial
Section C403.3 — Economizers — Commercial. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C403.5 Duct and Plenum Insulation — Commercial
Section C403.5 — Duct and Plenum Insulation — Commercial. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] C404.1 Service Water Heating — Commercial
Section C404.1 — Service Water Heating — Commercial. This section covers plumbing system requirements. Specific sizing, materials, and installation methods are in the official code text. Refer to the official code text for complete requirements.
[F] C405.1 General Lighting Requirements
Section C405.1 — General Lighting Requirements. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.2 Lighting Controls
Section C405.2 — Lighting Controls. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.2.1 Occupant Sensor Controls
Section C405.2.1 — Occupant Sensor Controls. This section establishes occupancy classification and use requirements that determine applicable building code provisions. Refer to the official code text for complete requirements.
[F] C405.2.2 Time Switch Controls
Section C405.2.2 — Time Switch Controls. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.2.3 Daylight-Responsive Controls
Section C405.2.3 — Daylight-Responsive Controls. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.2.4 Specific Application Controls
Section C405.2.4 — Specific Application Controls. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.2.5 Exterior Lighting Controls
Section C405.2.5 — Exterior Lighting Controls. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.2.6 Topside Daylighting Controls
Section C405.2.6 — Topside Daylighting Controls. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.2.7 Functional Testing Lighting
Section C405.2.7 — Functional Testing Lighting. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.3 Interior Lighting Power Allowance
Section C405.3 — Interior Lighting Power Allowance. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.3.1 Building Area Method
Section C405.3.1 — Building Area Method. This section covers allowable building height, area, and number of stories based on construction type and occupancy. Refer to the official code text for complete requirements.
[F] C405.3.2 Space-by-Space Method
Section C405.3.2 — Space-by-Space Method. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.4 Exterior Lighting — Commercial
Section C405.4 — Exterior Lighting — Commercial. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C405.5 Electrical Power and Motor Systems
Section C405.5 — Electrical Power and Motor Systems. This section covers electrical installation requirements. Specific conductor sizing, circuit protection, and installation methods are in the official code. Refer to the official code text for complete requirements.
[F] C405.6 Electrical Transformers
Section C405.6 — Electrical Transformers. This section covers electrical installation requirements. Specific conductor sizing, circuit protection, and installation methods are in the official code. Refer to the official code text for complete requirements.
[F] C501.1 Existing Building Scope
Section C501.1 — Existing Building Scope. This section establishes the scope, applicability, and administrative provisions for enforcement of this code. Refer to the official code text for complete requirements.
[F] C501.1.1 Existing Buildings Scope
Section C501.1.1 — Existing Buildings Scope. This section establishes the scope, applicability, and administrative provisions for enforcement of this code. Refer to the official code text for complete requirements.
[F] C501.2 Existing Building Compliance
Section C501.2 — Existing Building Compliance. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C501.2.1 Existing Buildings Scope
Section C501.2.1 — Existing Buildings Scope. This section establishes the scope, applicability, and administrative provisions for enforcement of this code. Refer to the official code text for complete requirements.
[F] C501.3 Maintenance
Section C501.3 — Maintenance. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C501.3.1 Additions General
Section C501.3.1 — Additions General. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C501.3.2 Additions Envelope
Section C501.3.2 — Additions Envelope. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] C501.4 NFRC Standards
Section C501.4 — NFRC Standards. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C501.4.1 Alterations General
Section C501.4.1 — Alterations General. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C501.4.2 Alterations Envelope
Section C501.4.2 — Alterations Envelope. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] C501.4.3 Alterations Mechanical
Section C501.4.3 — Alterations Mechanical. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] C501.4.4 Alterations Lighting
Section C501.4.4 — Alterations Lighting. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C501.5 Change in Space Conditioning
Section C501.5 — Change in Space Conditioning. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C501.5.1 Change of Occupancy
Section C501.5.1 — Change of Occupancy. This section establishes occupancy classification and use requirements that determine applicable building code provisions. Refer to the official code text for complete requirements.
[F] C501.6 Historic Buildings
Section C501.6 — Historic Buildings. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C502.1 Additions to Existing Commercial Buildings
Section C502.1 — Additions to Existing Commercial Buildings. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C502.1.1 Additions General
Section C502.1.1 — Additions General. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C502.2 Building Envelope Alterations
Section C502.2 — Building Envelope Alterations. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] C502.3 HVAC Alterations
Section C502.3 — HVAC Alterations. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] C502.4 Lighting Alterations
Section C502.4 — Lighting Alterations. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C502.5 Mechanical Systems in Additions
Section C502.5 — Mechanical Systems in Additions. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] C503.1 Alterations to Existing Buildings
Section C503.1 — Alterations to Existing Buildings. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C503.1.1 Alterations to Existing Commercial Buildings
Section C503.1.1 — Alterations to Existing Commercial Buildings. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C503.2 Envelope Requirements for Additions
Section C503.2 — Envelope Requirements for Additions. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] C503.3 HVAC Alterations
Section C503.3 — HVAC Alterations. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] C503.4 Lighting Alterations
Section C503.4 — Lighting Alterations. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] C503.5 Envelope Alterations
Section C503.5 — Envelope Alterations. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] C504.1 Repairs to Existing Building Envelope
Section C504.1 — Repairs to Existing Building Envelope. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] C504.2 Change of Occupancy Compliance
Section C504.2 — Change of Occupancy Compliance. This section establishes occupancy classification and use requirements that determine applicable building code provisions. Refer to the official code text for complete requirements.
[F] C505.1 Commercial Electrical Power and Lighting
Section C505.1 — Commercial Electrical Power and Lighting. This section covers electrical installation requirements. Specific conductor sizing, circuit protection, and installation methods are in the official code. Refer to the official code text for complete requirements.
[F] R401.1 Residential General
Section R401.1 — Residential General. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R401.2 Compliance Approach
Section R401.2 — Compliance Approach. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R402.1 Building Thermal Envelope
Section R402.1 — Building Thermal Envelope. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.1.1 Residential Insulation R-value
Section R402.1.1 — Residential Insulation R-value. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.1.2 Residential U-factor Alternative
Section R402.1.2 — Residential U-factor Alternative. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R402.2 Ceiling Insulation
Section R402.2 — Ceiling Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.2.1 Residential Ceiling Insulation
Section R402.2.1 — Residential Ceiling Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.2.2 Residential Wall Insulation
Section R402.2.2 — Residential Wall Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.2.3 Residential Floor Insulation
Section R402.2.3 — Residential Floor Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.2.4 Residential Basement Wall Insulation
Section R402.2.4 — Residential Basement Wall Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.2.5 Residential Crawl Space Wall Insulation
Section R402.2.5 — Residential Crawl Space Wall Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.2.6 Residential Slab-on-Grade
Section R402.2.6 — Residential Slab-on-Grade. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R402.3 Wall Insulation
Section R402.3 — Wall Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.4 Air Leakage
Section R402.4 — Air Leakage. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R402.4.1 Building Thermal Envelope Air Sealing
Section R402.4.1 — Building Thermal Envelope Air Sealing. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R402.4.2 Residential Fireplaces
Section R402.4.2 — Residential Fireplaces. This section addresses fire protection and life safety requirements. Specific provisions depend on building type, occupancy, and construction classification. Refer to the official code text for complete requirements.
[F] R402.5 Maximum Fenestration U-Factor
Section R402.5 — Maximum Fenestration U-Factor. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R402.6 Maximum Fenestration SHGC
Section R402.6 — Maximum Fenestration SHGC. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R402.7 Floors over Outdoor Air
Section R402.7 — Floors over Outdoor Air. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R402.8 Crawl Space Wall Insulation
Section R402.8 — Crawl Space Wall Insulation. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R403.1 HVAC Equipment Sizing
Section R403.1 — HVAC Equipment Sizing. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] R403.1.1 Residential Heat Pump Controls
Section R403.1.1 — Residential Heat Pump Controls. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R403.2 Residential Ducts
Section R403.2 — Residential Ducts. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] R403.2.1 Residential Duct Testing
Section R403.2.1 — Residential Duct Testing. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] R403.3 Duct insulation and sealing - Residential
Section R403.3 — Duct insulation and sealing - Residential. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] R403.4 Residential Mechanical Ventilation
Section R403.4 — Residential Mechanical Ventilation. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] R403.5 Residential Service Hot Water Systems
Section R403.5 — Residential Service Hot Water Systems. This section covers plumbing system requirements. Specific sizing, materials, and installation methods are in the official code text. Refer to the official code text for complete requirements.
[F] R403.5.1 Residential Heated Water Circulation
Section R403.5.1 — Residential Heated Water Circulation. This section covers plumbing system requirements. Specific sizing, materials, and installation methods are in the official code text. Refer to the official code text for complete requirements.
[F] R403.6 Equipment Efficiency
Section R403.6 — Equipment Efficiency. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R404.1 Residential Lighting Equipment
Section R404.1 — Residential Lighting Equipment. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R405.1 Simulated Performance
Section R405.1 — Simulated Performance. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R406.1 Energy Rating Index
Section R406.1 — Energy Rating Index. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R501.1 Existing Buildings Scope IECC
Section R501.1 — Existing Buildings Scope IECC. This section establishes the scope, applicability, and administrative provisions for enforcement of this code. Refer to the official code text for complete requirements.
[F] R501.1.1 Existing Residential Buildings General
Section R501.1.1 — Existing Residential Buildings General. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R501.2 Residential Existing Buildings General
Section R501.2 — Residential Existing Buildings General. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R501.3 Additions
Section R501.3 — Additions. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R501.4 Alterations
Section R501.4 — Alterations. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R501.5 Change in Space Conditioning (Residential)
Section R501.5 — Change in Space Conditioning (Residential). This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R502.1 Residential Alterations - Envelope
Section R502.1 — Residential Alterations - Envelope. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R502.2 Residential Alterations - Envelope
Section R502.2 — Residential Alterations - Envelope. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R502.3 Residential Alterations - HVAC
Section R502.3 — Residential Alterations - HVAC. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] R502.4 Residential Additions Duct Testing
Section R502.4 — Residential Additions Duct Testing. This section addresses mechanical system requirements including ventilation, ductwork, and equipment specifications. Refer to the official code text for complete requirements.
[F] R503.1 Alterations to Existing Buildings
Section R503.1 — Alterations to Existing Buildings. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
[F] R503.2 Residential Alterations Envelope
Section R503.2 — Residential Alterations Envelope. This section addresses energy conservation requirements including thermal performance and building envelope specifications. Refer to the official code text for complete requirements.
[F] R504.1 Repairs to Existing Buildings
Section R504.1 — Repairs to Existing Buildings. This section establishes specific code requirements. Refer to the official code text for detailed provisions, exceptions, and referenced standards. Refer to the official code text for complete requirements.
Code sections are sourced from the International Code Council (ICC) and NFPA. Refer to ICC Digital Codes or NFPA for the authoritative source documents.