Energy Audit and HERS Index – We’re Building Green, We Love Our Planet

A home energy audit, also known as a home energy assessment, helps to assess how much energy your home consumes and to evaluate what measures can be taken to make your home more energy efficient.

Since an energy efficient and sustainably built house is one of the goals in this whole project, this energy audit is key.

We have been working with Justin Erickson at E3 Energy LLC of Flagstaff, Arizona to meet the energy conservation requirements for Larimer County.  

Our county gives three options to comply to the 2015 IECC (International Energy Conservation Code).  

A prescriptive package is the first option.  This states that you need to meet or exceed the minimum requirements that they have specified for the geographic location.  These include things like a minimum of R-20 wall insulation and R-38 attic insulation, etc.

The second option uses RESnet software that we have never used before.  It’s a free download from but usually your architect will help you with this.  We did not however use an architect.

The third option uses an energy rater and the Home Energy Rating System (HERS) Index.

This program simulates the performance of home given its location, insulation package, heating/cooling equipment, window and door sizes, and appliances.  It then rates the home based on this information.  We will be inspected throughout the building process in order to show compliance with the IECC.

In an effort to build a home that can perform better than the minimum requirements, we opted to go with the HERS Index.

This method will give a precise forecast of what our house is going to require in terms of energy consumption. This seemed to be the only feasible option being building science geeks. Well that, plus we didn’t have to learn how to use another computer program.

We emailed Justin our plans and he entered the homes’ design information into REM/Rate, a program to determine what our level of performance will be according to the 2015 IECC.  The HERS Index rates a home against the performance of a standard home built in 2017 and a zero net energy home.  Houses constructed to the current standard is rated 100 and a zero net energy home is rated 0.  We came in at a 47 which is pretty good.  If we add solar, we’ll drop our index down even more but that’s just going to have to wait for now.

Energy Audit
Energy Audit

Yeah. How do you like them apples?

Also, a huge thanks to E3 Energy for helping us in our goal to make a green home! If you haven’t had an energy audit performed, you really should give E3 a call. Not located in any of the Four Corner states, you can find a current list on the Energy Star website. These audits will save you money and more importantly, help to save the planet.

energy efficient