An Introduction to the HERS Index and IECC Compliance

EEBA ERI HERS This five-part online course reviews building science principles as they relate to the Performance Path option in the International Energy Conservation Code (IECC). This course will introduce RESNET and the HERS Index and relate the principles of building science as they apply to HERS. Explore the ERI/HERS Index as a tool to successfully design and build houses that meet code using the ERI/Performance Path to compliance, while also meeting the minimum prescriptive requirements of the current IECC enforced and/or adopted in the region. Participants will learn about the strategies and tools used by HERS Raters to perform analysis of a house to produce a HERS Index Score. The last part of the session will be spent reviewing energy rating software that is most often used by HERS professionals and manipulating various construction assemblies to see the effect of HERS Index scores.

Gain confidence to achieve compliance with the performance path of the international energy code, and use it to expand construction options, materials choices, and building assemblies.  Integrate the HERS/ERI scores as a marketing feature of your high performance homes.

This course is now approved to provide the HERS Associate designation!

This new RESNET certificate level designation is essential for anyone needing a working understanding of RESNET and HERS for uses other than conducting ratings. The HERS Associate is targeted for supplier employees, but is also applicable to architects, engineers, code officials, builders, trade sub-contractors, appraisers, advocacy groups, and any other staff who interfaces with HERS Raters and HERS Ratings.

Learning Objectives:

  1. Understand basic building science terminology and principles as they relate to the International Energy Code.
  2. Introduction to RESNET, the HERS Index, and understanding the methods used in calculating an Energy Rating Index and HERS score.
  3. Understand the implications of different climate zones and building assemblies on the Energy Rating Index and HERS scores.
  4. Attain a working understanding of computer modeling and the major approved energy rating software packages used in calculating an energy rating.

Learn & Earn*

* All CEUs for the online course are currently pending.  Questions?  Please contact Nancy Bakeman at

Learning Modules

Houses are systems and understanding how the individual components interact is critical for success. This module focuses on the physics of how Heat, Air and Moisture flow, and how to use this knowledge for peak performance. Applying these principles leads to knowing how to diagnosis a building failure, comprehend a given product’s viability, optimize a system’s operation and design for all-around performance in terms of efficiency, control, comfort and health.

  • Understand the concepts of Houses = Systems
  • Grasp how Heat flows from hot to cold by conduction, convection and radiation
  • Appreciate how Air moves through holes caused by pressure differences (wind, stack, fans)
  • Value how Moisture goes from wet to dry in liquid (bulk, capillarity) or vapor (infiltration, diffusion)


Examine the energy code from a historical perspective and grasp the scope, basic structure and content of the latest energy codes. Appreciate the focus on details of the building thermal envelope as well as how code impacts the mechanical and hot water systems. Learn about prescriptive code starting points and also which items are mandatory requirements that must be satisfied. Finally, understand the four options for showing compliance with the insulation and window thermal requirements:

  • Understand prescriptive charts – the “recipe” to follow
  • Learn about UA Tradeoff – a simple insulation trade-off approach (by hand or with free RESCheck software)
  • Observe and learn about Simulated Performance Alternative – a full-on computer simulation that looks at energy costs but still only permits insulation trading
  • Comprehend the Energy Rating Index (ERI) – the newest computer simulation path that looks at all energy used in the home (and credits better HVAC equipment and appliances)

Presentation / Ventilation Strategies Handout

Modeling heat flow starts with some basic equations. Using computers to crunch the numbers, these calculations can be rapidly performed to simulate the energy performance of a home on an hourly basis. Using weather data for the home’s location, energy performance can be successfully modeled and the home’s design can be optimized for the most cost effective, code compliant strategy.

  • Learn simple heat flow calculations used in load calcs and UA trade-offs
  • Model a base home design to check for performance and code compliance
  • Experiment with a home’s design to obtain a target performance for the lowest first cost
  • Demonstrate the impact of renewables on the energy footprint

A high performance home isn’t just efficient and comfortable. It has to be a place where the occupants can breathe safely. Given that North Americans spend 90% of our lives inside of buildings, understanding indoor air quality (IAQ) is crucial to achieving healthy homes. Managing pollutants is the key to good IAQ and this module will address the pollutant hierarchy in four areas:

  • Source control – eliminating pollutants either by design or by deliberate action
  • Pollutant separation by managing and stopping the way they can get to the occupants
  • Diluting pollutants via flushing them out with intentional ventilation
  • Capturing pollutants with a deeper, pleated filter to remove them from the air stream.

Methods and standards for determining the minimum amount of fresh air required will be discussed. Also, strategies and technologies to provide fresh air for the building occupants will be presented and vetted, including:

  • Understanding negative pressure (e.g., continuous exhaust fan)
  • Learning about balanced systems (e.g., ERV)
  • Explore hybrid approaches (combination of fans)
  • Gain knowledge about positive pressure (in-line supply fans, fresh air ducted into the return, ventilating dehumidifiers, etc.)

Finally, the qualities of an ideal ventilation system will be discussed.

Having learned about energy modeling and the latest energy code compliance option, the ERI, a few of the fundamental tenants of the Residential Energy Services Network (RESNET) industry have been introduced. This module takes a deeper dive into the value added by having an official Home Energy Rating performed by a certified HERS Rater. Explore the structure of the industry and how the model for Quality Assurance (QA) maintains the high level of confidence through the work of certified Rating Providers. Explore the content of the HERS Rater training, details of a home assessment and how to market the benefits of a certified rated home. Finally, learn about different HERS business models and services a HERS Rater can provide such as:

  • High performance home design assistance through energy modeling and advisement
  • Understand the analysis and documentation for code compliance, tax credits and utility rebates
  • Learn about inspection and verification for beyond code programs (e.g., ENERGY STAR, EarthCraft, LEED Homes, NAHB Green),
  • Gain knowledge about technical assessments and diagnostics for existing home improvement projects.
  • See the impact of ratings by the numbers and discover ways of marketing certified HERS rated homes.