New Energy Code (for dummies!)

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The 2009 IECC energy code truly must be the first thing the U.S. Government has ever done that is hard to understand!  No need to panic, most building inspectors don’t even understand the new code.  Hopefully we can help you figure out what R-Value and insulation system you need to put in your building.  If at the very least, this information will help you know the ‘lingo’ when you are meeting with your local building code officials. This blog is based on our experience thus far with the energy code and will cover the most essential points related to metal buildings and the 2009 IECC code as we understand it.

Note:  Understand that complying with the energy code involves more than just the building envelope and insulation package.  The three areas involved are:  Building Thermal Envelope (insulation, openings for doors & windows, etc.), Mechanical (heating, cooling), Power & Lighting.

Here are some key steps to follow in understanding the code:

1) Is your building conditioned / temperature controlled?  If the building space is temperature controlled, you will need to insulate according to the climate zones and tables below.  IF THE BUILDING IS NOT TEMPERATURE CONTROLLED, THERE IS NO MINIMUM REQUIREMENT FOR INSULATION.  Even though there is no minimum requirement, many people use a minimum of 2″ (R-8) -6″ (R-19) to control any potential condensation and provide more comfort during the heat of the summer and cold of the winter.

2) Find your climate zone:  The map below shows the climate zones of the country in relation to the 2009 IECC energy code.

3) Now that you know your climate zone, find your climate zone on the table below.  Under the climate zone number, you will find the required R-Values for your commercial metal building under the “All Other” column.  Group R stands for residential dwellings. At this point you’ll see some R-Value combinations that don’t make much sense….  Don’t panic!  Now look at step 4.


4) The table below (502.2 (2)) has a great explanation of what each combination of R-Values listed in the table above (502.2(1)) means.  (Please see the corresponding illustrations)

5) Your next questions are probably regarding the use of the thermal blocks.  There has been quite a bit of discussion about the need of thermal blocks on the purlins and gurts, but when it comes right down to it…the difference is substantial!  Not only do the studies show dramatic increases in energy savings, but your building won’t pass a Comcheck without them.  It doesn’t matter if you have an R-60 in the roof and wall cavities, without a continuous insulation (thermal block), your building envelope won’t comply.  Here are a few talking points regarding thermal blocks:

  • What kind of thermal block can be used on a screw down roof? The only hot box tested thermal block with the compressive strength to handle snow and wind loads is the Sealed n’ Safe Thermal Block System.  (click here to go to their website)
  • What kind of thermal block can be used on a standing seam roof? The best option here is an 25 psi extruded polystyrene board, or a 2 lb expanded polystyrene board.  These are typically custom cut to 1″ x 3″ x 23″.
  • What kind of thermal block can be used on wall gurts? Since snow and wind loads aren’t as high on the walls, a standard rigid insulation board can be used as well as the Sealed n’ Safe Thermal Block System.

**Something to consider as you are putting together your building package is that whatever thermal block system you choose to go with, remember to order your trim and sheeting to accomodate the extra 1″ of material you are adding to the purlins and gurts.  Also, make sure to communicate with your building manufacturer about the thermal blocks and how they will affect the engineering and warranty of the building.

6)  Now that you’ve figured out everything you need to put into your building envelope in terms of insulation and R-values, it’s time to run everything through the United States Department of Energy’s COMcheck software (click for link) in order to get a certificate that your envelope meets the 2009 IECC energy code.  If you have any questions regarding the software, we are happy to help you through the process or there are several tutorials online to guide you through the software.  (click here for links to COMcheck help)