Skip to main content

- What is Passive Building?
  Your passive building questions, answered
  
  Passive Building
  
  Passive Building Principles
  
  Passive Building FAQs
  
  A Better Way to Zero
  
  Passive Building Foundations Training
- Sectors
  Passive isn't just for houses
  
  Single-Family
  
  Multifamily
  
  Office Buildings
  
  Schools
  
  Other Non-Residential
- Projects
  Phius Certified Projects are the most energy efficient and comfortable buildings in the world
  Find a Project
  
  Project Certification
  
  Submit a Project
  
  Certification Review Queue
- Products
  Phius Certified Products are guaranteed to perform to passive standards
  View Products
  
  Product Certification Overview
  
  Window Certification
  
  Panel Certification
- Professionals
  Phius Certified Professionals are on the cutting edge of high-performance building
  Find a Professional
  
  Phius Certified Consultant (CPHC®)
  
  Phius Certified Builder (CPHB)
  
  Phius Certified Rater
  
  Phius Certified Verifier
  
  Phius Certified Trades Professional
  
  Phius Associate
  
  Maintain Credentials
Our Approach
- New Construction
  Phius CORE and Phius ZERO provide the path for constructing a Phius building from the ground up.
- Retrofit
  Upgrade existing buildings to Phius standards using Phius CORE REVIVE and Phius ZERO REVIVE.
- Commercial
  Phius standards aren't just for residential buildings. Phius CORE COMM and Phius ZERO COMM can be applied to any non-residential building.
Categories
December 1 – January 16

Phius Certified Trades Professional - Enclosure Specialist Training | December 2025 & January 2026 | Portland, OR
Become a Phius Enclosure Specialist!
Upcoming Sessions
- Member Office Hours - Projects
  December 9
- Jan. Webinar: Walking Through METr
  January 13
- Member Office Hours - METr
  January 20
- Phius Certified Builder Training and Certification Exam | January 2026
  January 20 – 30
- Policy Work
  Promoting policies designed to grow passive building
  Policy Database
  
  Financial Incentives
  
  Codes
  
  Qualified Allocation Plans
  
  Cost Data
- Tools and Support
  Providing the tools you need to create healthier buildings
  Resource Library
  
  Certification Support
  
  Calculators and Protocols
  
  Feasibility Study
  
  METr Design Tool
  
  WUFI Passive Design Tool
  
  Climate Data
  
  Quality Assurance
  
  Tech Corner

Passive Building
- What is Passive Building?
  Your passive building questions, answered
- Sectors
  Passive isn't just for houses
Certifications
- Projects
  Phius Certified Projects are the most energy efficient and comfortable buildings in the world
  Find a Project
- Products
  Phius Certified Products are guaranteed to perform to passive standards
  View Products
- Professionals
  Phius Certified Professionals are on the cutting edge of high-performance building
  Find a Professional
Standards
Our Approach
- New Construction
  Phius CORE and Phius ZERO provide the path for constructing a Phius building from the ground up.
- Retrofit
  Upgrade existing buildings to Phius standards using Phius CORE REVIVE and Phius ZERO REVIVE.
- Commercial
  Phius standards aren't just for residential buildings. Phius CORE COMM and Phius ZERO COMM can be applied to any non-residential building.
Education
Categories
Upcoming Sessions
- Member Office Hours - Projects
  December 9
- Jan. Webinar: Walking Through METr
  January 13
- Member Office Hours - METr
  January 20
- Phius Certified Builder Training and Certification Exam | January 2026
  January 20 – 30
December 1 – January 16

Phius Certified Trades Professional - Enclosure Specialist Training | December 2025 & January 2026 | Portland, OR
Become a Phius Enclosure Specialist!
Resources
- Policy Work
  Promoting policies designed to grow passive building
  Policy Database
- Tools and Support
  Providing the tools you need to create healthier buildings
  Resource Library
About Us
Our People
Phius Alliance

Quick Links

Calculator/Tool

Thermal Bridge Psi-Value Calculator v25.1.1

This calculator can be used to determine psi-values for 2-D thermal bridges in combination with THERM.

August 15, 2025

By Phius Certification Team

Download the Thermal Bridge Psi-Value Calculator

Use this to calculate linear heat loss transmission coefficients (psi-values) for Phius certification. The workbook is set up to print 1-page thermal bridging reports that can also be presented to clients.