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Summary of Changes to the Energy Efficiency Standards

California state law requires that most new building construction (new buildings and additions/alterations to existing buildings) be in compliance with the Energy Efficiency Standards for Residential and Nonresidential Buildings (Standards). The Standards are updated and revised at regular building code change intervals (usually three to four years). The following is a summary of changes that were made to the 1995 Standards version and become effective July 1, 1999.

This overview is intended to serve as a convenient summary of changes only and does not address all changes made nor is it the definitive code itself. For exact wording and legal code, please see the California Energy Commission publication P400-98-001, Energy Efficiency Standards for Residential and Nonresidential Buildings, dated July 1999.

Windows/Fenestration (All Occupancies)
Ducts (All Occupancies)
Residential Kitchen and Bathroom Lighting
Residential Water Heating
Residential Envelope
Residential Space Conditioning
Residential Alterations-prescriptive
  Residential Alterations-performance
Nonresidential Envelope
Nonresidential Mechanical
Nonresidential Lighting
Nonresidential Additions and Alterations


  • All manufactured products must have a label with the U-value and Solar Heat Gain Coefficient (SHGC). These values can be NFRC or default values. The default values are found in the standards, Section 116.

  • All references to Shading Coefficient (SC) are now SHGC. The new requirements are equivalent to the SC requirements except for residential where the 0.40 SC is now 0.40 SHGC, which is slightly relaxed.

  • Field-fabricated fenestration does not need to be labeled. These products will use the default values. This term replaces site-built, and is defined as:

      FIELD-FABRICATED FENESTRATION PRODUCT OR EXTERIOR DOOR is a fenestration product or exterior door whose frame is made at the construction site of standard dimensional lumber or other materials that were not previously cut, or otherwise formed with the specific intention of being used to fabricate a fenestration product or exterior door. Field fabricated does not include site assembled frame components that were manufactured elsewhere with the intention of being assembled on site (such as knocked down products, sunspace kits and curtainwalls).

  • In buildings using the nonresidential standards (includes hotel/motel, and high-rise residential) glazed wall systems and overhead glazing do not need to be labeled. These products must still determine a U-value and SHGC using NFRC or default values.

  • Fenestration products removed and reinstalled as part of a building alteration or addition do not need labels.

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DUCTS (All Occupancies)

  • All pressure-sensitive tapes, mastics, aerosol sealants, or other closure systems must meet applicable UL 181 requirements.

  • Drawbands used with flexible duct shall:

    • (a) Be either stainless-steel worm-drive hose clamps or UV-resistant nylon duct ties.
    • (b) Have a minimum tensile strength rating of 150 pounds.
    • (c) Be tightened as recommended by the manufacturer with an adjustable tensioning tool.

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  • The general lighting must provide sufficient light for basic kitchen tasks and provide a uniform pattern of illumination. This prevents a light in the corner being considered general lighting.

  • The control for the general lighting must be on a readily accessible switch at an entrance to the kitchen. This eliminates the need for a switch at each entrance and eliminates the need to determine which switch is the "most" accessible.

  • Each room with a shower or bathtub (no reference to water closet) must have a high efficacy lamp; half-baths will not have any lighting requirements.

  • An alternative to the bathroom lighting is to install both of the following:

    • A high efficacy lamp in a utility room, laundry room, or garage; and
    • High efficacy lamps in all luminaires permanently mounted to the residence providing outdoor lighting, or all permanently mounted outdoor lighting equipped with a motion sensor.

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  • Credit for R-12 water heater insulation wrap is not allowed.

  • An R-12 blanket is mandatory on water heaters with an energy factor of less than 0.58.

  • The water heating budget does not include an R-12 blanket and prescriptive water heating requirements do not include the blanket. The proposed water heater will be compared to a minimally complying water heater (0.53 EF). The effect is that the applicant who formerly modeled water heating with an R-12 wrap will receive the same credit they've been receiving and no blanket will be required as long as it is 0.58 EF or higher.

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  • Thermal mass is not required for compliance with prescriptive Package D (Package E is eliminated because the mass requirements were the only difference between D and E). Additions will not require compliance with any thermal mass requirements. Credit for a passive solar design will be accommodated in performance compliance.

  • For performance compliance, solar heat gain coefficients (instead of SC) are 0.68 for draperies, 0.47 for blinds, and 0.47 for roller shades until December 31, 2001. Beginning January 1, 2002, roller shades cannot be used for compliance. These are the only acceptable values for interior shading devices.

  • Interior shading devices cannot be used to show compliance with prescriptive SHGC requirements. Prescriptive compliance requires a fenestration product with the required SHGC, an exterior shading device, or an overhang.

  • All prescriptive references to 0.66 SC were changed to "no requirement."

  • R-8 insulation for concrete raised floor (e.g., apartments with underground parking) is no longer a mandatory requirement. Prescriptive Package D requires R-8 in Climate Zones 1, 2, 11, 13, 14, and 16, R-4 is required in Zones 12 and 15, no concrete raised floor insulation is required in Zones 3-10.

  • Package D includes below grade (basement) wall insulation requirements. Climate Zones 1-15 do not require any insulation, Climate Zone 16 requires R-13 insulation.

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  • Prescriptive compliance can be achieved with any type of space heating (e.g., wall furnace) or space-cooling system that complies with applicable appliance efficiency requirements. A setback thermostat is required.

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  • New space-conditioning systems or components must meet applicable mandatory requirements and are limited to natural gas, liquefied petroleum gas, or the existing fuel type, unless it can be demonstrated that the source energy use of the new system is more efficient than the existing system. This provision was included to prevent equipment change-outs to a less efficient fuel source without compensating efficiency measures (as demonstrated using performance compliance).

  • New service water-heating systems or components must meet applicable mandatory requirements and are limited to natural gas, liquefied petroleum gas, or the existing fuel type unless it can be demonstrated that the source energy use of the new system is more efficient than the existing system. This provision was included to prevent equipment change-outs to a less efficient fuel source without compensating efficiency measures (as demonstrated using performance compliance).

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  • A new provision for existing plus alteration is provided for situations where the applicant cannot or does not want to meet the 0.75 U-value for windows or wants to change from gas or liquefied petroleum heating or water heating to electric.

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  • A new category of "semi-conditioned" building will comply with lighting requirements.

  • A semi-conditioned building is a nonresidential building with conditioning that currently does not meet the definition of directly conditioned-less than 5 Btu/hr./ft.2 of cooling, less than 10 Btu/hr./ft.2 of heating, evaporative cooling, wood heat, conditioned for a process environment below 55 or above 90 degrees fahrenheit.

  • The definition of directly conditioned was clarified with regard to process environment. It has also been expanded so that spaces with, for example freeze protection where the space is not maintained outside the comfort range, are not directly conditioned:

      DIRECTLY CONDITIONED SPACE is an enclosed space that is provided with wood heating, is provided with mechanical heating that has a capacity exceeding 10 Btu/(hr.-ft.2), or is provided with mechanical cooling that has a capacity exceeding 5 Btu/(hr.-ft.2, unless the space-conditioning system is designed and thermostatically controlled to maintain a process environment temperature less than 55 degrees fahrenheit or to maintain a process environment temperature greater than 90 degrees fahrenheit for the whole space that the system serves, or unless the space-conditioning system is designed and controlled to be incapable of operating at temperatures above 55 degrees fahrenheit or incapable of operating at temperatures below 90 degrees fahrenheit at design conditions.

  • Definitions of mechanical cooling and mechanical heating remove the phrase "for the purpose of maintaining human comfort."

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  • The heat gain and heat loss equations were updated for accuracy and the heat gain equation now considers the effects of opaque surfaces.

  • Prescriptive high-rise residential requirements include insulation for concrete raised floors (e.g., apartments with underground parking) to match low-rise requirements— R-4 in Climate Zones 12 and 15, R-8 in Climate Zones 1, 2, 11, 13, 14, and 16.

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  • Prescriptive fan power limitations for variable air volume systems are changed to reflect improvements in technology and system efficiency. Individual VAV fans with motors over 25 HP (adjusted for air filtering systems) must meet one of the following:

    • (a) The fan motor shall be driven by a mechanical or electrical variable speed drive.
    • (b) The fan shall be a vane-axial fan with variable pitch blades.
    • (c) The fan motor shall include controls that limit the fan motor demand to no more than 30 percent of the total design wattage at 50 percent of design air volume when static pressure set point equals 1/3 of the total design static pressure, based on certified manufacturer's test data.

  • A new exception to prescriptive economizer requirements is provided for spaces or rooms with a dedicated space conditioning system where the use of outdoor air is detrimental to equipment or materials, e.g., computer room, telecommunications equipment room.

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  • Reduced control credits for lumen maintenance (from 10 to 5 percent) and for combined occupancy sensor and lumen maintenance (from 37 to 25 percent).

  • Lighting levels in all compliance approaches are reduced to account for T-8 lamps with electronic ballasts in place of T-12 lamps with magnetic ballasts. Reductions are not a straight percentage, but are based on the prevalence of fluorescent lighting in the building model.

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  • Wording is added to clarify how the standards apply/do not apply to a change of occupancy.

  • When an existing semi-conditioned nonresidential buildings is undergoing a lighting alteration, the same requirements apply as for any other lighting alteration. However, when a space is converted from unconditioned to semi-conditioned, no requirements (lighting, mechanical or envelope) apply.

  • One of the options for envelope alterations will require compliance with the requirements of Section 143 "for the altered component," except when a portion of an entire building's fenestration is repaired or replaced, or 50 square feet or less of glass is added. In such cases, compliance with the solar heat gain coefficient requirements of Section 143 is not required.

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PAGE UPDATED: July 24, 2001