Duct and Envelope Tightness (DET) Verification Training

This two-day course is designed to introduce the skills necessary to become a Duct and Envelope Tightness (DET) Verifier, certified to perform the diagnostic testing required for new homes by the 2009 and 2012 IECC amendments.


After successful completion of this course, the participant will be able to test the leakage of a building envelope and duct system, and evaluate the results as measured against Georgia code requirements. Specific topics include:

  • Protocols for blower door and duct leakage testing
  • Calculations for ACH50 and percent duct leakage
  • Tips for successfully completing the written and in-field DET Verifier certification exams
  • This course also prepares participants to successfully take the Building Performance Institute (BPI) Infiltration and Duct Leakage (IDL) certification field exam (available separately). NOTE: The BPI IDL exam and BPI IDL certification are NOT required to become a certified DET Verifier. Click here to view BPI’s website for more information about BPI IDL certification. Click here to learn more about scheduling BPI exams at Southface.


  • CEUs: AIA 16 LU, BPI 8 units, ICC 1.4 CEUs
  • Certifications: Duct and Envelope Tightness Verifier. To achieve designation as a DET Verifier, a student must receive a passing score on both exams (included in tuition costs).

Training Includes

  • DET training workbook
  • Written DET Verifier exam
  • In-field DET Verifier exam
  • RECA Guide
  • Certificate of course completion
  • Breakfast and lunch


  • LMS Courses: Math Basics for DET Verifiers module (access provided upon registration)


Additional Information:

  • Students must bring a calculator for the field and written exam.


This course is supplemental and not primary for career development.