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2018 WSEC effective date delayed to Feb. 1, 2021 (update: June 30, 2020)

At a meeting of the Special Council of the Washington State Building Code Council, the Council voted to delay the effective date to February 1, 2021.

2018 WSEC effective date delayed to Nov. 1, 2020 (update: April 3, 2020)

As part of Governor Inslee's proclamation to delay the implementation of the Washington State Building Code, the implementation date for the Washington State Energy Code-Residential has been delayed from July 1, 2020, to November 1, 2020.

Today’s Proclamation by Governor Inslee is available here.

2018 WSEC-R Training (update: March 10, 2020)

Due to the COVID-19 outbreak in the Puget Sound region, the professional meetings where we planned to deliver WSEC training sessions in March have been cancelled or re-scheduled by the host organizations at the direction of local public health authorities.

We recorded the 2018 WSEC-R training presentation this week and will post it on our Training webpage in the next day or two. We will notify those on our email distribution list when the training is available.

Email us at to be added to this list. We appreciate your understanding.

2018 Washington State Energy Code (update: Jan. 8, 2020)

Our code experts provide support to those who use the residential sections of the Washington State Energy Code (WSEC-R). The 2018 code will go into effect July 1, 2020. All residential structures permitted on or after July 1, 2020, must meet the requirements of the 2018 code. The 2018 WSEC-R is available here.

We are working with stakeholders to determine the most effective way to provide technical assistance and training about the 2018 code. We anticipate receiving a high volume of requests for assistance in early 2020; thank you in advance for your patience as we prepare this information.

Technical Assistance with the Washington State Energy Code-Residential

Our code experts provide support to those who use the residential sections of the Washington State Energy Code (WSEC-R). The 2015 code will remain in effect until February 1, 2021.

Questions about the residential code?

Email or call the WSEC Residential Code Hotline at 360-956-2042.

To get updates about the code and training opportunity details, join our distribution list by contacting us at

Questions about non-residential portions of the code?

Contact Evergreen Technology Consulting at 360-539-5300 or email

Versions of the Washington State Energy Code

All residential structures permitted on or after February 1, 2021, will be required to meet the requirements of the 2018 WSEC-R, available here.

All residential structures permitted before February 1, 2021, must meet the requirements of the 2015 WSEC-R, which went into effect July 1, 2016 (visit the Washington State Building Code Council website for updates).

For 2012 Residential Energy Code information and forms, click here.

Energy Code Worksheets

Forms and worksheets for the 2015 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 Webinars 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: right-click the link and select "Save target as" so you can complete this worksheet on your computer

Table R406.2 2015 Energy Credits

2015 Prescriptive Energy Code Checklist

Suggested Option Combinations: This document contains combinations of options from Table 406.2 to achieve 3.5 credits, which is the amount needed for an average-size house in Washington (1,500 to 5,000 square feet). Numerous other combinations are available, but the following utilize readily available equipment and/or some minor upgrades to the building envelope.

Energy Credit Option Combinations

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. This calculator sizes heating systems only; it will not accurately size cooling systems.

The form has embedded instructions; hover your cursor over the red triangles to see the help notes. An instruction sheet is also provided below.

Heating System Sizing Worksheet

Heating System Sizing Instructions

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 in the Webinars and Videos section, which explains how to complete the worksheet.

Total UA Alternative Worksheet

Alterations: Requirements for alterations or remodels of existing structures differ from the requirements for new construction. No credits from Table 406.2 are required and existing buildings are not necessarily required to meet all of the requirements of the energy code. This worksheet will show what is required for your remodel and may be filled out using Excel or by hand.

Alterations (Remodel) Worksheet

Code Text

We provide support for the residential code only.

2015 Washington State Energy Code – Residential – 2nd printing

2015 Washington State Energy Code – Commercial

2015 Washington State Energy Code – Appendices

Compliance Publications and Tools

These resources pertain to the residential sections of the 2015 WSEC.

Appendix Ruleset for TSPR - Total System Performance Ratio

Blower Door Test Results Form

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 2015 Certificate 1/4 Sheet (Avery 6878)

WSEC 2015 Certificate 1/2 Sheet (Avery 6573)

Insulation Certificate

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

Benefits of Duct Sealing brochure

Scheduled Trainings

We offer training on the residential sections of the 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 2015 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 2015 WSEC.

Database of PTCS Technicians

Home Energy Raters (HERS)

This list provides contact information for certified home energy raters.

The Energy Program has supported home energy raters since 2005. A flier is available that details:

  • The programs supported by NW home energy raters
  • The benefits of home energy ratings to builders and their customers
  • How WSU ensures the credibility of home energy raters and their equipment
  • Contact information for RESNET-certified home energy raters in the Northwest under the WSU RESNET providership

Webinars and Videos


This webinar is for the 2012 WSEC.

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

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


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

WSEC 2015 Residential Energy Code Updates

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