ICC E2 key terms

The adopted set of mandatory rules governing energy efficiency in commercial buildings, covering envelope, mechanical, water heating, lighting, and power systems. It sets minimum requirements for design, construction, and alteration, and is enforced through plan review and field inspection.

The authority having jurisdiction who administers and enforces the energy code. This person reviews permit applications, approves alternate methods, issues permits and certificates of occupancy, and may inspect or require inspections to confirm compliance.

The pre-construction examination of permit documents by the code official to verify that proposed designs satisfy energy code requirements. Reviewers check envelope assemblies, equipment efficiency ratings, lighting power densities, and required compliance documentation before issuing a permit.

One of the alternative methods the code allows for demonstrating compliance, such as the prescriptive approach, the trade-off or system-performance approach, or whole-building energy modeling. Each path has its own documentation and calculation requirements.

A compliance method that checks each building component against fixed, individually stated requirements, such as minimum insulation levels or maximum lighting power density. It involves no trade-offs between components and is the simplest route to demonstrate compliance.

A compliance method that evaluates the whole building's predicted annual energy use, often through computer simulation, and compares it to a baseline building meeting the code minimum. It allows flexibility in how efficiency targets are met across systems.

A compliance method permitting limited exchanges between building components, so that one assembly may be less efficient if another is more efficient, provided the overall package meets the code's stated criteria. Documentation must show the combined result satisfies requirements.

A computer-based simulation of a building's energy consumption used to compare proposed designs against a code-defined baseline. It accounts for envelope, lighting, equipment, schedules, and climate data, and must follow approved modeling rules and assumptions.

The reference design, configured to meet the minimum requirements of the energy code, against which a proposed building's simulated energy use is compared. Its characteristics and operating assumptions are fixed by the code to ensure fair comparison.

The reports, calculations, forms, and certificates submitted to the code official showing that a design or installation meets energy code requirements. Examples include envelope and lighting compliance forms and equipment efficiency documentation retained for inspection.

The document issued by the code official permitting a building to be occupied, contingent on verification that construction complies with applicable codes, including energy provisions. It is typically withheld until required inspections and compliance documentation are complete.

A code provision allowing the code official to approve designs, materials, or systems that differ from prescribed requirements when evidence shows they achieve equivalent or greater energy efficiency and safety. Approval is documented and specific to the project.

The boundary separating conditioned interior space from unconditioned or exterior space, including walls, roofs, floors, windows, doors, and foundations. Its thermal performance strongly influences heating and cooling loads and is regulated by the energy code.

The continuous layer of insulation and related materials that resists heat flow through the building envelope. It must be installed without gaps, compression, or thermal bridging that would reduce the assembly's rated performance.

A measure of a material's resistance to heat flow; higher values indicate better insulating performance. The code sets minimum R-values for envelope assemblies such as walls, roofs, and floors, and installation must preserve the rated value.

A measure of how much heat passes through an assembly per unit area and temperature difference; lower values mean better performance. It is the reciprocal of R-value and is used for windows, doors, and whole-assembly envelope ratings.

All glazed openings in the building envelope, including windows, curtain walls, storefronts, skylights, and glazed doors. The code regulates their U-factor, solar heat gain, and air leakage, and limits the amount of glazed area relative to wall area.

The fraction of incident solar radiation admitted through a fenestration product, either directly transmitted or absorbed and released inward. Lower values reduce cooling loads, and the code sets maximum values based on climate and orientation.

A continuous system of materials that resists uncontrolled air movement through the building envelope. It must be sealed at joints, penetrations, and transitions, and its continuity is verified during inspection to limit infiltration and exfiltration losses.

The unintended movement of air through cracks, joints, and penetrations in the building envelope or ductwork. The code limits leakage through envelope assemblies and requires sealing of ducts, dampers, and other components to control energy loss.

A path of high heat conductance, such as structural framing or metal cladding supports, that bypasses insulation and reduces assembly performance. The code requires continuous insulation or other measures to limit these losses.

Insulation installed as an uninterrupted layer outside or within the assembly, without framing penetrating through it. It reduces thermal bridging and helps the assembly achieve the code-required U-factor or R-value.

A geographic classification based on temperature and moisture conditions used by the energy code to set climate-specific envelope and equipment requirements. Buildings in colder zones typically need higher insulation levels, while hot zones emphasize cooling and solar control.

The ratio of total fenestration area to gross wall area for a building or portion of a building. The code limits this ratio under prescriptive compliance and uses it to calculate allowable lighting and envelope trade-offs.

The heating, ventilating, and air-conditioning equipment and distribution serving a building's conditioned spaces. The code regulates its efficiency ratings, sizing, controls, duct insulation, and economizer requirements.

A standardized measure of an HVAC or water-heating appliance's performance, such as SEER, EER, COP, or AFUE. The code requires equipment to meet minimum ratings, verified through manufacturer data and nameplate information at inspection.

A control strategy that uses outdoor air for cooling when conditions are favorable, reducing mechanical cooling energy. The code requires economizers above certain capacity thresholds and in specified climate zones, with proper controls and damper operation.

A control approach that modulates outdoor air intake based on measured occupancy or carbon dioxide concentration rather than design occupancy. The code may require it in spaces with varying occupancy to save fan and conditioning energy.

The requirement to seal joints, seams, and penetrations in ductwork and plenums to limit air leakage. Sealing levels and testing requirements depend on duct location and system size, and verification may occur during inspection.

Thermal insulation applied to ducts and plenums to reduce heat gain or loss between the air handler and conditioned spaces. Required R-values depend on duct location and climate, and installation must be continuous and undamaged.

The systems that heat and distribute domestic hot water for fixtures and processes. The code regulates equipment efficiency, pipe insulation, temperature controls, and circulation pump operation to limit energy waste.

Thermal insulation wrapped around hot water and steam piping to reduce heat loss. The code specifies minimum thickness or R-values based on pipe size and temperature, and requires protection of insulation from damage and moisture.

The maximum allowed lighting wattage per unit of floor area for a space or building, expressed in watts per square foot or square meter. It is calculated using the code's space-by-space or building-area method and verified during inspection.

Devices and strategies that reduce lighting energy use, such as occupancy sensors, daylight-responsive dimming, time switches, and manual controls. The code requires specific controls in defined space types and confirms their installation and function.

Automatic controls that reduce electric lighting output in response to available daylight in sidelit or toplit zones. The code requires them in specified spaces and requires documentation that sensors and dimming operate correctly.

The sensors, thermostats, timers, and building automation devices that regulate HVAC, lighting, and water-heating operation. The code requires specific control functions, such as setbacks, shutoffs, and deadbands, and inspectors verify they are installed and functional.

The process of verifying that building systems are designed, installed, and calibrated to operate as intended and meet code requirements. It includes functional performance testing and documentation, and the code official may require evidence of completion.

The procedure of operating installed systems and controls to confirm they perform their intended functions, such as economizer dampers modulating or occupancy sensors switching lighting. Results are recorded and made available to the code official.

The last field verification by the code official confirming that construction and installed systems match approved plans and comply with the energy code. It typically precedes issuance of a certificate of occupancy and may include a review of compliance documents.

A field inspection performed before concealment of building components, such as insulation, ducts, and piping, to verify correct installation. Work found noncompliant must be corrected before it is covered, since later verification becomes difficult.

The manufacturer's label on equipment listing model, capacity, and efficiency ratings. Inspectors compare nameplate information with approved plans and compliance documentation to confirm installed equipment meets code minimums.

A field test that pressurizes a building to measure envelope air leakage. Results can demonstrate compliance with air-tightness requirements and help locate leaks; the code may require such testing or accept it as verification evidence.