While the first comprehensive Seattle Energy Code took effect in February 1980, Seattle has had residential insulation requirements since 1974 and the first furnace sizing and duct insulation requirements took effect in 1927. A summary of ordinances and key changes follow. In case of conflicts between information herein and the ordinances themselves, the actual ordinances shall govern.
- Effective dates for building envelope insulation and other energy-related requirements
- Conversions from unheated to heated space: quick reference to most stringent envelope requirements in effect
EFFECTIVE DATES FOR BUILDING ENVELOPE INSULATION AND OTHER ENERGY-RELATED REQUIREMENTS
This section contains a summary of the effective dates for building envelope insulation and other requirements in versions of the Seattle Energy Code (SEC), the Washington State Energy Code (WSEC), the Seattle Building Code (SBC), and the Seattle Mechanical Code (SMC). Building permit applications submitted on or within the time period listed are subject to the code version indicated. If the application date is unknown, the building permit issuance date may be used.
2006 SEATTLE ENERGY CODE (2006 WSEC w/2006 Seattle amendments)
(Ordinance 122530 - effective 10 November 2007 to present, transition period allows the use of the 2004 Energy Code until 8 January 2008)
Summary: Applies to all occupancies. For WSEC residential: glazing U-0.35 maximum for single-family/duplex, maximum heating equipment size of 150% of design heating load, residential exterior lighting to be high-efficacy or controlled by motion sensor. For WSEC nonresidential: adoption of 2004 Seattle nonresidential requirements for alterations to mechanical systems, commissioning, default U-factor tables for metal stud walls, semiheated space insulation, setback and shutoff controls, hydronic systems, variable flow systems, cooling towers; incorporation of ASHRAE Standard 90.1 and national Energy Policy Act (EPAct) requirements for increased efficiencies for mechanical equipment, exit lights, and transformers. For SEC nonresidential: building envelope criteria generally made the same as electric resistance for all fuel types; add requirements for loading dock weatherseals, vestibules, and mechanical modifications for incorporation of ASHRAE Standard 90.1 requirements; fenestration SHGC-0.35 maximum or to have overhang, higher equipment efficiencies, more efficient lighting for office and larger retail spaces. For more details, see the 2006 Seattle Energy Code summary.
2004 SEATTLE ENERGY CODE (2004 WSEC w/2004 Seattle amendments)
(Ordinance 121821 - effective 6 July 2005 to 9 November 2007)
Summary: Applies to all occupancies. For WSEC residential: minor change added for partially-filled wall cavities. For WSEC nonresidential: building envelope criteria updated for mass walls and metal frame walls and fenestration U-factor and SHGC to be no less stringent than ASHRAE Standard 90.1-2001, threshold for economizer lowered to 20,000/54,000 Btuh, equipment efficiencies updated to ASHRAE Standard 90.1-2001, all buildings over 5000 sf to have automatic shutoff controls and occupancy sensors for small offices, office lighting power allowance reduced to 1.0 W/sf. For SEC nonresidential: prescriptive SHGC alternate added for plastic dome skylights. For more details, see the 2004 Seattle Energy Code summary.
2003 SEATTLE ENERGY CODE (2003 WSEC w/2003 Seattle amendments)
(Ordinance 121522 - effective 15 August 2004 to 5 July 2005, transition period allows the use of the 2002 Energy Code until 14 October 2004)
Summary: For WSEC residential and nonresidential: Editorial changes to update references to I-codes. For SEC nonresidential: table provided to clarify requirements for alterations to existing mechanical systems that do not have economizer, building envelope criteria for semi-heated spaces to be same as fully-heated spaces except for walls, demand control ventilation required for assembly spaces, prescriptive economizer alternates added for water source heat pumps systems with partial air economizer and for server rooms with high cooling loads, and mechanical equipment efficiencies updated to correspond with ASHRAE Standard 90.1. For more details, see the 2003 Seattle Energy Code summary.
2002 SEATTLE ENERGY CODE (2001 WSEC w/2002 Seattle amendments)
(Ordinance 120804 - effective 1 July 2002 to 14 August 2004)
Summary: Applies to all occupancies. For WSEC residential: prescriptive paths apply to all fuel types, similar to previous electric resistance requirements. For WSEC nonresidential: equipment efficiencies updated to ASHRAE Standard 90.1-2001. For SEC nonresidential: exterior lighting power allowances reduced, revision to RS-29 to allow the use of a prototype system. For more details, see the 2002 Seattle Energy Code summary.
2001 SEATTLE ENERGY CODE (2000 WSEC plus additional 2001 Seattle amendments)
(Ordinance 120525 - effective 24 October 2001 to 30 June 2002, transition period allows the use of the 2000 Energy Code until 28 February 2002)
Summary: Additional Seattle amendments apply to all nonresidential occupancies. For SEC nonresidential: Building envelope glazing to have low-e coatings and solar control coatings, better insulation for walls (including continuous insulation or equivalent for metal frame walls), increased insulation for semi-heated spaces; mechanical systems to have increased minimum equipment efficiencies and motor efficiencies, revised economizer thresholds, revised sizing limits and exceptions, more heat recovery applications, better controls for parking garage ventilation; and lighting in daylight zones to have dimming controls (either stepped or continuous dimming), offices less than 300 square feet to have occupancy sensors, prescriptive lighting option to have continuous dimming controls, office lighting power allowance reduced to 1.0 W/sf. For more details, see the 2001 Seattle Energy Code summary.
2000 SEATTLE ENERGY CODE (2000 WSEC plus carrying over 1997 Seattle amendments)
(Ordinance 120378 - effective 1 July 2001 to 23 October 2001)
Summary: Applies to all occupancies. For WSEC overall: duplicative and conflicting chapters combined (2 & 12, 7 & 17, 10 & 20). For WSEC residential: clarifies that prescriptive paths are for wood framing only, metal framing to use tradeoff procedure, clarifies tradeoff calculation procedure for additions, establishes good practice duct sealing requirements, oversized furnaces to have 90% efficiency, establishes lighting wattage limits for common areas and lighting control requirements for hotel/motel guest rooms. For WSEC nonresidential: large street-level windows to have low-e glass, prescriptive path for electric resistance space heat only applicable to wood framing, HVAC equipment to be in certification program, sets cap on retail lighting exemptions, incorporates some 1997 Seattle amendments. For SEC nonresidential: carryover of 1997 SEC amendments.
1997 SEATTLE ENERGY CODE (1997 WSEC w/1997 Seattle amendments)
(Ordinance 119081 - effective 15 August 1998 to 30 June 2001, transition period allows the use of the 1994 Energy Code until 13 October 1998)
Summary: Applies to all occupancies. For WSEC residential: separate U-factors for skylights, defaults added for garden windows and metal stud walls, HVAC equipment sizing limit increased to 200%, efficiency established for combination space and water heating equipment. For WSEC nonresidential: defaults added for metal stud walls, metal buildings, vertical glazing. For SEC nonresidential: carryover of 1994 SEC amendments, add selected requirements from Second Public Review Draft of ASHRAE/IESNA 90.1-1989R (including optimum start controls, automatic controls for parking garages, completion requirements - building commissioning, performance alternate for VFD for fans), plus building envelope prescriptive path for semiheated spaces with skylights, threshold for automatic lighting controls in office buildings changed to 5,000 square feet, additional defaults for vertical glazing.
1994 SEATTLE ENERGY CODE w/1995 WSEC amendments
(Ordinance 117698 - effective 12 August 1995 to 14 August 1998)
Summary: Applies to all occupancies. Minor amendments to WSEC.
1994 SEATTLE ENERGY CODE (1994 WSEC w/1994 Seattle amendments)
(Ordinance 117081 - effective 29 April 1994 to 11 August 1995)
Summary: Applies to all occupancies. First Seattle Energy Code to consist of the Washington State Energy Code with Seattle amendments as insert pages. Significant change in format - WSEC subdivides code into Group R occupancy (residential, chapters 1-10) and other than Group R occupancy (nonresidential, chapters 11-20). For WSEC residential: minor changes, nonresidential requirements deleted from Chapters 1-10. For WSEC nonresidential: envelope and HVAC comparable to ASHRAE/IES Std. 90.1-1989, simple systems option for HVAC, lighting power allowances reduced. For SEC amendments: primarily carryover of 1991 SEC requirements.
1991 SEATTLE ENERGY CODE w/1992 WSEC amendments
(Ordinance 116159 - effective 1 July 1992 to 28 April 1994)
Summary: Applies to all occupancies. Minor amendments. Allows use of NFRC glazing rating procedure and prohibits non-IC rated lighting fixtures in shell of building. Adds minimum equipment efficiencies for large heat pumps per ASHRAE/IES Std. 90.1-1989.
1991 SEATTLE ENERGY CODE
(Ordinance 115641 - effective 1 July 1991 to 30 June 1992)
Summary: Applies to all occupancies. Group R occupancy revised to match 1991 Washington State Energy Code. Other than Group R occupancy similar to ASHRAE/IES Std. 90.1-1989.
October 1986 SEATTLE ENERGY CODE w/1990 WSEC amendments
(Director's Rule 24-90 - effective 1 July 1990 to 30 June 1991)
Summary: Applies to all occupancies. Revises component performance calculation procedure for Group R occupancy. Provides log house compliance option.
October 1986 SEATTLE ENERGY CODE w/1989 WSEC amendments
(Ordinance 114549 - effective 1 July 1989 to 30 June 1990)
Summary: Applies to all occupancies. Minor amendments. Requires outside combustion air to be ducted directly to woodstoves. Minor adjustments in insulation R-values.
October 1986 SEATTLE ENERGY CODE
(Ordinance 113058 - effective 24 October 1986 to 30 June 1989)
Summary: Applies to all occupancies. Minimum standards for all occupancies revised to comply with Washington State Building Code Council (WSBCC) September 1986 revisions to the April 1986 WSEC. Other minimum standards for other than Group R occupancies revised for consistency with April 1986 WSEC. (Overall code provides equivalent energy savings to the 1986 Model Conservation Standards of the Northwest Power Planning Council.)
April 1986 SEATTLE ENERGY CODE
(Court ruling - effective 1 April 1986 to 23 October 1986)
Summary: Applies to Group R occupancy only, all other occupancies still subject to the January 1986 SEC. Standards for low-rise residential buildings, as defined in the April 1986 WSEC, apply to all Group R occupancy including high-rise residential, hotel and motel, as defined in the Seattle Building Code. Major projects requirements for Group R occupancy no longer in effect.
January 1986 SEATTLE ENERGY CODE
(Ordinance 112500, court ruling - effective 1 January 1986 to 23 October 1986)
Summary: Applies to all occupancies other than Group R occupancy, Group R occupancy still subject to the April 1984 SEC.
1984 SEATTLE ENERGY CODE
(Ordinance 111460 - effective 14 April 1984 to 31 March 1986 for Group R occupancy only,
effective 14 April 1984 to 31 December 1985 for all occupancies other than Group R occupancy)
Summary: Major projects' requirements take effect - 10% minimum energy efficiency improvements required for all projects with 50,000 or more gross square feet of conditioned floor area. Standards for smaller projects unchanged.
November 1980 SEATTLE ENERGY CODE
(Ordinance 109416 - effective 8 November 1980 to 13 April 1984)
Summary: Applies to all occupancies. Minimum standards raised where necessary to comply with the June 1980 WSEC.
February 1980 SEATTLE ENERGY CODE
(Ordinance 108500 - effective 20 February 1980 to 7 November 1980)
Summary: Applies to all occupancies. First comprehensive energy code for all occupancies.
1979 SEATTLE ENERGY CODE
(Ordinance 108508 - effective 17 October 1979 to 19 February 1980)
Summary: Applies to Group R occupancy four stories or less only. Building envelope standards similar to those in Washington State House Bill 98.
1979 SEATTLE MECHANICAL CODE
(Ordinance 106166 - effective 27 February 1979 to 19 February 1980)
Summary: Applies to all occupancies. Duct insulation only.
1977 SEATTLE BUILDING CODE
(Ordinance 106350 - effective 7 May 1977 to 16 October 1979)
Summary: Applies to Group H and Group I occupancies only. Revised building envelope standards.
1974 SEATTLE BUILDING CODE amendment
(Ordinance 103985 - effective 14 December 1974 to 6 May 1977)
Summary: Applies to hotels, motels, apartment houses, lodging houses, dwellings, and other residential buildings. First building envelope standards.
1927 ordinance
(Ordinance 52113 - effective 1 January 1927 to 26 February 1979)
Summary: Applies to all occupancies. Warm air furnace sizing procedures: assumes 175°F supply air temperature and 55% heater efficiency, requires water pan or humidifying device and duct insulation.
This section provides a quick general reference to the worst case minimum applicable requirements when unheated space is converted to heated space. For specific information, refer to the ordinances listed previously. In this case, there are no exceptions for structural limitations or any other reasons. If the alterations requirements are more stringent, they shall be complied with. (The dates listed here refer to the date that a complete building permit application was filed.)
Group R occupancy
Other than Group R occupancy
- Roof/ceiling insulation:
R-38 minimum: 1 April 1986 to present
R-30 minimum: 20 February 1980 to 31 March 1986
R-19 minimum: 15 December 1974 to 19 February 1980 - Wall insulation:
R-21 minimum: 1 July 2002 to present
R-19 minimum: 1 April 1986 to 30 June 2002
R-11 minimum: 15 December 1974 to 31 March 1986 - Floor insulation:
R-30 minimum: 1 July 1991 to present
R-19 minimum: 1 April 1986 to 30 June 1991
R-11 minimum: 15 December 1974 to 31 March 1986 - Slab on grade floor insulation:
R-10 minimum: 1 July 1991 to present
R-8 minimum: 1 April 1986 to 30 June 1991
R-4.25 minimum: 20 February 1980 to 31 March 1986
R-4 minimum: 7 May 1977 to 19 February 1980
- Glazing U-factor:
U-0.35 maximum (NFRC certified) for 15% area: 10 November 2007 to present
U-0.40 maximum (NFRC certified) for 15% area: 29 April 1994 to 9 November 2007
U-0.40 maximum (tested) for 15% area: 1 July 1991 to 28 April 1994
U-0.60 maximum (tested) for 21% area: 1 April 1986 to 30 June 1991
U-0.65 maximum (calculated): 15 December 1974 to 31 March 1986 - Glazing area limitation:
15% of FLOOR area: 1 July 1991 to present
21% of FLOOR area: 1 April 1986 to 30 June 1991
21% of WALL area: 20 February 1980 to 31 March 1986
- Roof/ceiling insulation:
R-38 minimum: 29 April 1994 to present
R-30 minimum: 20 February 1980 to 28 April 1994 - Wall insulation:
R-13 cavity + R-7.5 continuous insulation minimum for metal framing (U-0.062):
10 November 2007 to present
R-13 cavity + R-3.8 continuous insulation minimum for metal framing (U-0.084):
24 October 2001 to 9 November 2007
R-19 minimum: 29 April 1994 to present
R-11 minimum: 20 February 1980 to 28 April 1994 - Floor insulation:
R-30 minimum: 29 April 1994 to present
R-19 minimum: 24 October 1986 to 28 April 1994
R-11 minimum: 20 February 1980 to 23 October 1986 - Slab on grade floor insulation:
R-10 minimum: 29 April 1994 to present
R-14 horiz./R-7 vert. minimum: 1 July 1991 to 28 April 1994
R-8 minimum: 24 October 1986 to 30 June 1991
R-5 minimum: 1 January 1986 to 23 October 1986
R-4.25 minimum: 20 February 1980 to 31 December 1985
- Glazing U-factor:
U-0.40 maximum (NFRC certified) for 20% area: 29 April 1994 to present
U-0.49 maximum (calculated) for 40% area: 1 July 1991 to 28 April 1994
U-0.61 maximum (calculated): 24 October 1986 to 30 June 1991
U-0.65 maximum (calculated): 20 February 1980 to 23 October 1986 - Glazing solar heat gain coefficient (SHGC):
SHGC-0.35 maximum (NFRC certified) for 30% area: 10 November 2008 to present
SHGC-0.40 maximum (NFRC certified) for 20% area: 24 October 2001 to 9 November 2007
SHGC-0.45 maximum (NFRC certified) for 40% area: 29 April 1994 to 23 October 2001 - Glazing area limitation:
20% of WALL area: 1 July 1991 to present
21% of WALL area: 20 February 1980 to 30 June 1991
