Bookmark and Share

2012 Washington State Energy Code

Our code experts provide support to those who use the residential sections of the Washington State Energy Code (WSEC). The 2012 code went into effect July 1, 2013 (visit the Washington State Building Code Council website for updates).

Have questions about the residential code?

Email or call the WSEC Residential Code Hotline at
360-956-2042. Other resources to help you include:


Code Text

Compliance Publications & Tools

Energy Code Worksheets


Scheduled Trainings

List of Duct Testers

Presentations & Videos

Hot Topics


For non-residential code resources, contact the Evergreen Technology Consulting at 360-539-5300 or email


Sign up to receive email updates about energy code changes and educational opportunities from the Energy Code listserv.

Code Text

We provide support regarding the residential code only.

2012 Washington State Energy Code – Residential

2012 Washington State Energy Code – Commercial

2012 Washington State Energy Code – Appendices

Compliance Publications & Tools

These resources pertain to the residential sections of the 2012 WSEC.

Blower Door Test Results Form

2012 Prescriptive Energy Code Checklist

Duct and Blower Door Test Hand Calculator

Duct and Blower Door Test Calculator

Duct Testing Standard (RS-33)

Duct Testing Affidavit (New Construction)

Duct Testing Affidavit (Existing Construction) - Jurisdictions, please contact us for a modifiable copy of the Duct Testing Affidavit

Air Leakage Testing

WSEC 2012 Certificate ¼ Sheet (Avery 6878)

WSEC 2012 Certificate ½ sheet (Avery 6573)

Insulation Certificate

Getting to Know Your Ventilation System: Exhaust Type - Whole House

Benefits of Duct Sealing brochure

Energy Code Worksheets

Forms and worksheets for the 2012 WSEC have changed. Instead of being group into one workbook, the Prescriptive Worksheet, Glazing Schedule, and Heating System Sizing Calculator are now independent documents. If you have trouble using any of these worksheets, view the webinar in the Presentations and Videos section of this page, which explains how to complete these worksheets.

Prescriptive Method. This approach is the simplest method of WSEC code compliance. A project complies with building envelope requirements if it meets all minimum insulation levels required for the applicable climate zone. This Excel file provides a method for documenting compliance with the prescriptive standards.

Prescriptive Worksheet – All Climate Zones

Table R406.2 Energy Credits

Glazing Schedule: Using the Prescriptive Method, all glazing must have an “area weighted average” U-Factor of 0.30. This means that some windows can have a higher U-factor than 0.30 and some can have a lower U-factor than 0.30, as long as the area weighted average is U-0.30 or lower. You may need to complete this form to document glazing compliance when applying for your building permit.

Glazing Schedule

Heating System Sizing Calculator: This calculator - a simpler version of previous worksheets for newly constructed buildings - assumes that your glazing products have an area weighted average of U-0.30. Use the dropdown boxes to choose insulation levels and enter the areas of each building component. The form has embedded instructions; hover your cursor over the red triangles to see the help notes. This calculator sizes heating systems only; it will not accurately size cooling systems.

Heating System Sizing Worksheet

Total UA Alternative Worksheet (formerly Component Performance): The Total UA Alternative worksheet has been updated to provide the user with error prompts when information is incorrect or missing. If you are having trouble using the worksheet, view the webinar under the Presentations and Videos section of this page, which explains how to complete the worksheet.

Total UA Alternative Worksheet

Scheduled Trainings

We offer training on the residential sections of the 2012 WSEC and on duct testing protocols.

Training Details and Schedule

List of Duct Testers

We have compiled a list of individuals who attended the one-day duct testing training offered by the WSU Energy Program and meet the minimum requirements to test ducts for the 2012 WSEC.

Technicians who can verify that they have successfully completed duct testing training provided by the Northwest ENERGY STAR Program or Performance Tested Comfort Systems (PTCS) may also be qualified to test ducts under the 2012 WSEC.

Database of PTCS Technicians

Database of Northwest ENERGY STAR Vrifiers

Presentations and Videos


Washington State Energy Code Forms: Prescriptive Worksheet, Glazing Schedule, Heating System Sizing Calculator

Washington State Energy Code Forms: Total UA Alternative Approach (formerly Component Performance)

Duct Sealing Video

"Duct Sealing for Comfort, Energy, and Indoor Air Quality" (16:45 min.)

Air Leakage In Homes: The Invisible Thief

Our air sealing video is divided into seven chapters:


Why Air Seal?

Air Sealing For New Homes

Measuring Building Tightness

Air Sealing for Existing Homes

Combustion Safety

Final Thoughts

New   Fresh Air for a Healthier Home

This consumer’s guide to ventilation systems video is divided into six chapters. You can choose to view an individual chapter or select Play All.

Why Ventilate?

Exhaust-only Systems

Integrated Systems

HRV/ERV Systems

Installation & Inspection

Upgrading Existing Homes

Play All

Washington State Energy Code Presentations

These trainings are frequently modified to meet jurisdictional needs and improve quality. Past presentations include:

2012 WSEC Residential Compliance Training

Duct Testing Training

Ventilation and Indoor Air Quality Training

"Hot Topic" Archives

ACEEE Ducts Inside

Additions and Ducts

Comparing the Moisture Performance of Wood-Framed Wall Systems

Conditioned Crawl Spaces

Efficient Water Heating

Electric Heat Lock Out on Heat Pumps

Energy Efficient Home Cooling

Externally Applied Building Insulation

Indoor Air Quality - Keeping Homes Dry

Inspecting Attic Insulation

Principles of Heat Transfer

Unvented Attics

Insuladd - Ceramic-Based Paint Additive

UltraCBF rFOIL - Foil-Faced Bubble Wrap


Click on the question to show or hide the answer

Support and Training

Q: Who do I contact with questions about the WSEC?
Contact the WSU Energy Program. We receive funding to provide technical assistance on the residential sections of the WSEC.


Phone: 360-956-2042

Contact: Luke Howard, Seth Kolodziejski, and Tanya Beavers

The Northwest Energy Efficiency Council (NEEC) provides technical assistance on sections of the WSEC that focus on multi-family residential and commercial buildings.


Phone: Lisa Rosenow 206-624-0283


Q: I would like to attend an Energy Code class. Where can I learn more?
A: Check out our Events and Trainings page. Online registration is available for classes that are posted. If you do not see a class time or location that works for you, sign up for the email Listserv to be notified of trainings as they are scheduled.

Duct and Blower Door Testing

Q: Do you have to be certified to perform blower door testing?
A: No. At this time, the 2012 WSEC does not require certification to perform an air leakage test on a house. We highly recommend that air leakage testing personnel attend the one-day duct and air leakage class to make sure they are aware of the maximum allowed leakage rates, test pressures, and proper set-up of the testing equipment.

Energy Code Requirements

Q: Where can I find a copy of a previous energy code? My house was built in 19XX; what were the energy code requirements then?

A: Depending on how well the home originally complied with the applicable energy code at the time it was built, the prescriptive requirements of the WSEC may not apply. Homes may have used component performance or systems analysis to comply with the code. Systems analysis was used far more frequently in the 1990s than it is used now. The appropriate version of the code is determined by the date when a building department received a complete permit application, not the date of construction, so the permit could have been issued under a previous code version.

Download copies of previous energy codes

New - 2012 WSEC

Q: In the 2012 WSEC, the Climate Zones have changed. What are the new Climate Zone designations?
A: Washington state has three ICC-designated climate zones: Climate Zones 5 and 6 and Marine 4. Due to a recent emergency rule by the State Building Code Council, all areas of the state have the same energy code requirements. The map shows climate zones for all counties in the state.
Q: Have the duct leakage rates changed in the 2012 WSEC?
A: Yes. The duct maximum leakage rates in the 2012 WSEC are 4% of the conditioned floor area of the structure (3% if the air handler is not installed). This rate applies to all test methods: total duct leakage at rough-in, total duct leakage at final and leakage to exterior test.
Q. Has the hot water piping R-value requirement changed and do hot water pipes inside the house need to be insulated?
A: The Washington State Building Code Council reduced the R-value of hot water piping from R-4 to R-3 through the emergency rule making process. The SBCC also issued an interpretation relating to insulating hot water pipes inside the conditioned space. The interpretation can be found here: . Click on interpretation # 13-15.
Q: Can whole house ventilation fans be operated intermittently or do they need to operate continuously?
A: The Washington State Whole House Ventilation requirements were based on intermittent operation for many years. The national residential ventilation standard developed by ASHRAE (ASHRAE Standard 62.2) is based on using lower flow fans operating continuously. New fan sizing charts in the code are based on continuously operating lower flow fans. You can operate whole house fans intermittently by increasing the fan size - sometimes drastically. IMC Table 403.8.5.1 lists fan size factors for different intermittent operating percentages.

Example: How do I size my whole house fan for a 2,200 square foot house with 3 bedrooms? I want to operate the fan 75% of the time.

First, size the fan from IMC Table 403.8.1. A 60 CFM continuously operated fan is required.

To determine the size of the fan operated 75% of the time, use the factor in Table 403.8.5.1 (the answer is 1.3).

Size of intermittently operated fan: 60 X 1.3 = 78 CFM. The timer needs to be set to run 3 hours out of every 4-hour segment.