All Energy Policy
New rebate structure update and highlights of the Xcel Energy ENERGY STAR® New Homes Program 2016 accomplishments.
Total year-end program results from 2016:
- 5,300 total completed houses
- 145,835 net Dekatherms and 4,957,801 net kilowatt-hours in energy savings
- $3,361,890 in builder rebates and energy rater administrative fees
- 1,800 earned the $100 ENERGY STAR rebate
Program and Rebate Changes for 2017/18, effective for homes submitted after March 1st:
- Homes will qualify for rebates based on the percent improvement better than the local adopted IECC code
- Rebate levels are increased for homes built in jurisdictions where IECC 2012 and newer codes are enforced
- The $10 ENERGY STAR dishwasher rebate is discontinued and the clothes washer rebate is reduced from $50 to $30
- The High Efficiency Lighting rebate is unchanged for homes built in jurisdictions where IECC 2009 and older codes are enforced
- For homes built in jurisdictions where IECC 2012 and newer codes are enforced, a $10 rebate is available if 100% of lighting is CFL or LED fixtures and/or bulbs
|Percent Better Than Local Code Improvement||Builder Rebate – IECC 2009 and older||Builder Rebate – IECC 2012 and newer|
|10.0 – 14.999%||$200||$250|
|15.0 – 19.999%||$350||$400|
|20.0 – 24.999%||$500||$600|
|25.0 – 29.999%||$650||$900|
|30.0 – 34.999%||$800||$1,300|
|35.0 – 39.999%||$1,000||$2,000|
|40% and higher||$1,400||$2,550|
|Appliance/Lamp||Builder Rebate – IECC 2009 & older||Builder Rebate – IECC 2012 & newer|
|Lighting Efficiency (CFL or LED)||$20 (20+ qualifying bulbs)||$10 (100% qualifying bulbs)|
|ENERGY STAR®, Xcel Gas & Electric||$100||$100|
Who to Contact:
Logistics/Customer Support Supervisor
EnergyLogic assesses compliance with the Federal tax credit for every home that we inspect. In addition, we provide a tax credit compliance report that is signed for every home that is tested.
Over the past several years EnergyLogic has had to reissue these tax credit documents due to software updates that have also changed the physical look and content of the document. Due to the need to reissue the reports, we were able to issue new passing tax credit certificates and lump them together for your convenience. The reports were typically sent in an email at the beginning of the year or a builder login was issued directing you to pull these reports from our DASH data system.
For 2016 homes, EnergyLogic will not need to re-run tax credit certificates or make any adjustments to the certificates you have already received. Therefore, builders will not be receiving an email containing all passing tax credits. EnergyLogic has already emailed all final report packets to you at the time the home has been rated and certified. Within those final report packets, you will find the tax credit certificate. It clearly states on the tax credit certificate if the home passes or not. In addition, the tax certificate is signed only for the homes that pass.
Builder Login for EnergyLogic’s DASH database
You can also access these final report packets using your builder login to EnergyLogic’s DASH database. Contact Tracy Larson at firstname.lastname@example.org if you need directions, username and password for the DASH builder login. Tracy will be sending you a spreadsheet in the next few weeks that lists all homes that qualified for the tax credit which will narrow down the list of packets you’ll need to locate and make your search easier.
The Federal tax credit expired on January 1st, 2017. As in the past, Energylogic will continue to issue tax credit certificates for all homes that we inspect. We will do this because historically every time the tax credit has expired it has been re-authorized and made effective retroactively to the date it expired. For example, on January 1st, 2015 the tax credit expired. In December of 2015. the tax credit was re-authorized to be effective from January 1st, 2015 through December 31st, 2016. The only way we can be sure that your homes will be able to get the credit if the tax credit is re-authorized is to keep track of whether they pass or not at the time of the final inspection. We strongly recommend that your office file the tax credit certificates for those homes that pass and are signed off on, so you are prepared to file for your credit if and when re-authorization occurs.
At this time, because nobody knows if re-authorization will occur, EnergyLogic does not recommend changing your building specification to optimize for the tax credit.
Additional information regarding the rebate structure and requirements is located on our website.
Who to Contact:
Principal, Director of Builder Relations
RESNET Adopts Standard Amendment on Persistence of the Use of Previous Versions of HERS Software When Standards Change
The latest release of Rating software, represented by the new ANSI/RESNET/ICC 301-2014, has dramatically demonstrated an issue that has been apparent for quite some time. To further expand on how various software versions impact changes to HERS Index scores, and how the recently adopted amendment, effective February 16, 2017, applies, please review the following:
- When standards and software are updated, the HERS Index score can change. In the case of ANSI/RESNET/ICC 301-2014 the score change is dramatic.
- As the HERS Index continues to grow in our national vocabulary, consistency of the scoring system becomes increasingly important.
As the standards are currently written, homes in a community with a buildout of twenty years can use old software because software does not have to be updated due to the notion of “Persistence”. If left open to interpretation, one Projected Rating could be applied to multiple building permits in production housing, allowing “Persistence” based on a Projected Rating to extend the use of older software versions to 5, 10, or even 20 years.
After the RESNET Standard Public Review and Comment process, the RESNET Standards Management Board has adopted Amendment #2017-01.
- The amendment requires that “Confirmed or Sampled Ratings on homes with a building permit date that is on or after the six-month anniversary of the release of the software must utilize the newly released software.
- Homes with a building permit date before the six-month anniversary of the release of the software will be allowed to complete a Confirmed or Sampled Rating based on the previous version of the software that was utilized for the Projected Rating.”
The amendment also allows the RESNET Board of Directors to stipulate a timeframe other than the six-month anniversary of the building permit date. The RESNET Board of Directors has not used this clause to date.
The adopted amendment is posted at RESNET Standard Amendment #2017-01
The amendment goes into effect on February 16, 2017.
Link to related article: HERS® Rating Scores Going Up
Who to Contact:
Principal, Director of Builder Relations
EnergyLogic is in the news! Check out this interview with Robby Schwarz, one of the founders and continuing principals here at EnergyLogic. You’ll find the article supporting how EnergyLogic continues to help builders, salespeople, and consumers in our industry better understand the long-term benefits that energy efficiency will bring to their lives.
To access the article, please click on the link below:
Who to Contact:
Principal, Director of Builder Relations
In July of 2015, EnergyLogic began informing you about upcoming software changes. As a reminder, the Residential Energy Services Network (RESNET) began to align the energy rating reference home to the 2006 IECC almost two years ago. The reference home, which currently reflects the 2004 IECC supplemental code, is what your home is compared to in order to create the HERS Index score. RESNET has gone through a process of taking the rule set for how to develop the HERS Index score through the ANSI process in order to create the ANSI/RESNET/ICC 301-2014 Standard for the Calculation and Labeling of the Energy Performance of Low-Rise Residential Buildings using an Energy Rating Index. The main impetus for this ANSI Standard arose from the desire to use the Index Score for code compliance and the adoption of the Energy Rating Index (ERI), a HERS path, as a compliance matrix for the 2015 IECC.
The alignment with the 2006 IECC has three primary effects on the HERS reference home.
- First, the updated 2006 IECC reference home infiltration rate became tighter to better reflect the improved tightness levels of newly constructed homes.
- Second, the updated 2006 IECC reference home window solar heat gain coefficient (SHGC) went from 0.55 in climate zones 4 through 8 to a SHGC of 0.40 in those climate zones. This updated value reflects the market penetration of improvements in basic window technology and is in alignment with the 2006 IECC.
- Lastly, revised mechanical ventilation requirements are used in the HERS reference home which are now aligned with the ASHRAE 62.2-2013 ventilation standard.
Scores to Increase by 2 to 6 Points
Philip Fairey, Deputy Director of the Florida Solar Energy Center and a consultant for RESNET, performed research on the impact of these changes on the HERS Index values of rated homes in all eight climate zones. His research has demonstrated that the HERS Index values will increase across all climate zones by a range of 2 to 6 points due to the reference home alignment with the 2006 IECC that occurred through the creation of the ANSI/RESNET 301-2014 Standard. EnergyLogic has been working with the newly released software, and we are seeing results that are consistently on the high end of the range (3-8 HERS Index points) when comparing homes that were rated with software developed prior to the ANSI standard adoption. RESNET is mandating that HERS providers begin using the new software on January 1, 2017. EnergyLogic has worked with RESNET to find ways to reduce the impact of the implementation of the ANSI standard software. A few things are, or have been, changed but the impact of the score increase will remain significant, affecting every home across the country.
Incorporating Water Heating
The development of the ANSI standard has also given RESNET the opportunity to include additional features related to water heating. This is specific to energy use related to hot water distribution and does not take into account water conservation. RESNET is working on a Water Index score that will address water conservation. The ANSI standard addendum allows the HERS Index score to quantify the efficiency or loss of energy through; pipe runs from the water heater to the farthest fixture, hot water pipes that are insulated, on-demand recirculation systems, high-efficiency low flow fixtures, and drain water heat recovery systems. If all of these systems are deployed in a home, the technologies can provide builders approximately 1-3 point reduction in the HERS Index.
It is important to also understand that if a builder is currently utilizing a water delivery system that is not delivering the hot water efficiently then the HERS Index would be penalized. For example, if you are currently using a timer or continuous recirculation loop to deliver hot water, your home’s HERS Index will be penalized. This will result in a higher score than the normal transition to the ANSI approved software. So, in this example, if the transitioning to the ANSI approved software took a HERS Index from 60 to 65, the inefficient hot water circulation system could add another 5-10 points, taking the score to 70 or 75. It is important to evaluate your current specifications and choose the most efficient water distribution systems, such as an on-demand hot water recirculation system, or stop installing them all together.
Summary: All Homes will Be Affected
These changes will affect every home that is rated but should have minimal impact on the use of the Index score for demonstrating compliance with programs such as EnergyStar, as the program’s energy Index target will fluctuate in unison with the home that is being rated. In the same way, these changes should have minimal effects on code compliance when utilizing the Simulated Performance path as the code reference home is separate from the HERS reference home. For those few builders utilizing the 2015 IECC Energy Rating Index path (ERI), these changes will be significant. Lastly, builders utilizing the Index score in their marketing efforts will need to update HERS related marketing collaterals.
Principal / Director of Builder Relations
The Q3 Field Fusion event delved into air-sealing and sound transmission challenges in multi-family units through a guided discussion that included perspectives from Code Officials, Insulators, and Raters. Read more here.
There are many complexities that accompany building townhomes and duplexes. For example, townhomes and duplexes built with common fire separation walls (party walls) are twice as leaky as single family houses that are twice their size.
The shaft wall, which we see most often in Colorado, is open directly to the outside through the designed gap between the shaft liner and the framing, thus creating a leaky assembly. An additional complexity arises when the reduction of unit-to-unit sound transmission is taken into account, which requires correctly installed insulation.
EnergyLogic’s August 31st Field Fusion delved into the details of these assemblies through a guided discussion that included perspectives from Code Officials, Insulators, and Raters.
We must first define what part of the shaft wall assembly is fire-rated, as the entire assembly is not. This is an important distinction that allows for more air sealing options once understood.
In chapter 3 of the IRC, Section R302 “Fire Resistant Construction” and Section R302.2 “Townhouses” states, “The common wall shared by two townhouses shall be constructed without plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing.”
This statement in the IRC is our first indication that the two layers of sheetrock in the shaft liner wall are the fire-rated two-hour wall, designed to slow the spread of fire from unit to unit. Thus, the two layers of 1” drywall cannot be penetrated with ducts.
The framing (which is held off the fire-rated assembly by a clip) often has ducts or plumbing in it and is specifically designed to burn and separate from the two-hour assembly when the clip melts. This allows one unit to burn and fall before fire is able to pass through to the adjacent unit. The UL (Underwriters Laboratory) listing for many of these assemblies’ references section 705 of the International Building Code (IBC) which states in Section 705.2 “Structural Stability”, “Fire walls shall have sufficient structural stability under fire conditions to allow collapse of construction on either side without collapse of the wall for the duration of time indicated by the required fire-resistance rating.” This is another indication that UL listings and the code are in agreement that the fire assembly is the two layers of 1” drywall and not the framing adjacent to the drywall.
It is important to point this out because throughout Colorado there is not a common understanding of what constitutes a shaft liner fire-rated party wall assembly. Some jurisdictions still hold that the assembly is the drywall, air gap, clip, framing and interior drywall while others hold that it is as explained above. What is consistent is the understanding that the assembly must be built continuously from the foundation to the roof deck.
EnergyLogic suggests having a discussion with jurisdictions, in an effort to:
- Ensure a common understanding of this assembly
- Determine how the assembly will be air sealed to control airflow to meet the air leakage requirements of the energy code.
One thing to note: jurisdictions throughout the state require that the two layers of sheetrock run continuously from the foundation to the roof deck, but not the entirety of the rest of the assembly. The most conspicuous example is the interior drywall, which is always missing on the ventilated attic side of the party wall.
Challenge: How to Achieve 3 ACH50?
Now that a common understanding of the assembly has been achieved, it is time to determine how the assembly can be air sealed in order to meet the air leakage target of 3 ACH50 for the 2012 and 2015 IECC. Most jurisdictions have not amended the requirement to meet this airtightness level, so pre-planning is crucial in order to be successful.
The clip that holds the framing off the two-hour party wall assembly creates a 1” gap that is connected directly to the outside at the front and back of the unit, as well as to the attic. This is where the UL listing of the assembly comes into play. UL is an American safety consulting and certification company that provides the one or two-hour rating for fire-rated assemblies by testing them in a laboratory environment. The UL listing for these assemblies is often mixed up with code’s definition of the assembly, which creates confusion regarding what materials are allowed to be used to seal them.
UL often refers to fire-blocking materials. Fire blocking materials are usually defined within the UL assembly and can be any one of the following:
- 2” nominal lumber
- Two thicknesses of 1” nominal lumber with broken lap joints
- One thickness of 0.719” wood structural panel with joints backed by 0.719” wood structural panel
- One thickness of 0.75” particleboard with joints backed by 0.75” particleboard
- Gypsum board, including 1” DensGlass Ultra® Shaftliner and 5/8” DensArmor Plus drywall
- Batts or blankets of mineral wool or fiberglass
- Other approved materials installed in such a manner as to be securely retained in place shall be permitted as an acceptable fire block (Section 717.2.1, 2006 IBC).
As some fire blocking materials are air barriers and some are not it important to choose a material that can stop the flow of air. EnergyLogic has seen the most success when builders tackle fire blocking on each individual floor.
Application: The Picture Frame Method
When looking at the party wall assembly, envision a picture frame around the perimeter of the wall. All four sides need to be fire blocked. The material of choice right now is the same 1” gypsum board used in the 2-hour rated assembly. Install the 1” gypsum board in the 1” gap between the interior of the unit and the outside at the front and back of the units, between floors, and to the attic. Again, picture framing the party wall.
Depending on your foundation type, if you are standing on the first floor you will need to air-seal the two layers of gypsum and the bottom plate to the slab in the shaft wall, or address the rim joist connection in the basement or crawl space to the shaft wall. At the rim joist be sure sill seal has been installed between foundation and sill plate as it is your primary capillary break, then seal the sill plate to foundation, seal rim board to the sill plate, and seal the rim board to sub floor. Pay special attention to any knockouts for foundation bolts.
Once the large 1” gap has been fire blocked with an air-impermeable material such as gypsum, seal the smaller gaps between the fire block and the shaft wall and the fire block and the framing. A fire-rated caulk or expanding foam works for this. Following these steps, with careful attention to detail, should enable you to successfully achieve 3 ACH50.
A few words of caution:
- Ensure that the drywall lid is air-tight: duct boots and other penetrations need to be sealed. In addition, as required by ENERGY STAR, the drywall to top-plate should be sealed. (This is a requirement of code that is generally not enforced.)
- Mechanicals can derail all good air-sealing intentions. Undampered ducts run to the exterior for combustion or ventilation air as well as atmospherically vented appliances. These combustion air ducts can ruin one’s ability to build a tight home that gains control and predictability of the airflow in the building.
Don’t Forget: Sound Reduction
Lastly, these assemblies should reduce sound transmission from dwelling unit to dwelling unit. The party wall is assumed to be an adiabatic wall, i.e. there is no heat loss or gain through the wall between two conditioned spaces as the temperature is the same on each side. Therefore, the insulation is primarily installed to lower sound transmission. The principles of sound reduction and heat flow are the same, so proper installation of the insulation in the framed cavity of the party wall is imperative.
NAIMA, the North American Insulation Manufacture Association, states that the installation of insulation in a party wall application should “comply with the manufacturers’ instructions including filling the entire stud cavity and cut to fit around outlets, junction boxes, and other irregularities in the cavity.” In other words, the insulation in a common party wall should be installed to a RESNET, Grade 1.
To learn more please see EnergyLogic’s Tech Bulletin on “Fire-rated Party Walls” which includes an article by Building Science Corporation.
Have a technical question? Contact Robby Schwarz.
Our next event will take place on November 16th. It is focused on Selling High-Performance Homes. Our guest speaker, Todd Gamboa, President of Building Trust LLC., has a wealth of experience and perspectives to share. Please see details here.
If you have suggestions for topic you would like to see discussed in depth, please let us know. We will be releasing our Q1 2017 event topic and date soon.
Principal / Director of Builder Relations
Field Fusion: The disconnect between Fire Code and Energy Code
Fire rated assemblies, air tightness, and the real world
Location: Bad Daddy’s, 100 E 120th Ave, Northglenn, CO 80233
3:00 – 5:00 PM
Robby Schwarz, Principal and Director of Builder relations at EnergyLogic, Inc
- Laying out the issue. Fire code vs. energy code and air leakage requirements that have to be met. Why multi-family homes are twice as leaky as single-family homes that are twice their size.
Gil Rossmiller, Chief Building Official for the City of Parker
- A perspective from a Code jurisdiction on what defines a fire rated assembly and what is being allowed to make them air tight.
Brian Firestone, Applegate Insulation
- Fire and Acoustical rated assemblies. UL listings the process and the options that are available.
5:00 – 7:00 PM
EnergyLogic’s Mixer and networking
This event is generously supported by Tyvek.
Up and down the front range of Colorado we are seeing more and more code jurisdictions adopt either the 2012 or 2015 IECC. From a building science perspective, this is a step forward toward better performing buildings because these two codes require mandatory air leakage targets be met by all segments of residential construction three stories or less. What I mean by this is that the code understands the importance of gaining control and predictability of the air flowing through our buildings. I like to say that air is a freight train and like a train it carries cargo from point A to point B. The cargo it carries is heat/energy, moisture, and pollutants. The issue is that air does not always carry its cargo in a straight line on tracks from inside a house directly outside the house and deposit its load into the ambient air. A properly ducted fan may take air and its cargo to the outdoors, but often air takes its cargo into building assemblies and deposits it there, causing long-term building durability and efficiency issues for our homes. The code now recognizes that tight homes increase durability and efficiency and now understand that visual inspection itself cannot ensure house tightness. The fundamental change in the code from the 2009 IECC to the 2012 or 2015 IECC is this recognition and the move from a choice to administer a blower door test or visually inspect to a mandate that you visually inspect and test to ensure tightness of the homes we build.
EnergyLogic tests homes and has been helping builders use the Simulated Performance pathway through code since the 2006 IECC. Unlike other pathways in the energy code, the flexibility gained in the performance path allows for the most cost-effective means to develop the energy specifications for a house because we can trade off house tightness for R-values and U-values in the thermal envelope. This means that we understand that there is absolutely no problem achieving the code required 3 air changes per house at 50 Pascals (3 ACH50) in a single-family home. In fact, the 2012 and 2015 IECC offer a checklist for how to be successful in the mandatory air barrier and insulation table R402.1.1. We also know with certainty that it is not easy for multi-family buildings to achieve this same air leakage target. Currently, code does not recognize the difficulty of achieving 3 ACH50 in multi-family homes and buildings. The City of Denver has accepted EnergyLogic’s code amendment to allow multi-family homes and buildings to have a leakage rate of 4ACH50. The city of Fort Collins allows a CFM/sqft of shell area measurement to be used to express air leakage in multi-family project. So far they are the only jurisdictions in the state that I am aware of that have amended this section of the code to better reflect the realities of creating airtight multi-family buildings. On a national level, EnergyLogic has submitted a code change proposal for the 2018 IECC that makes a clear distinction between single-family detached homes and multi-family attached homes with achievable air leakage targets for both. We will have to wait until October to see if the proposal is accepted.
So where does that leave our multi-family builders?
Whether you are building duplexes, townhouses, or stacked multi-family buildings, house tightness is solely dependent on attention to detail with regard to air sealing adiabatic common fire rated walls, floors, and ceilings. We recommend beginning by removing all draft-stopping materials (rock wool and fiberglass that are air permeable) in these fire rated assemblies and replacing them with solid fireblocking materials that actually stop the movement of air. By doing this you now have reasonable-sized holes that, depending on the jurisdiction, the assembly, and the skill level of the air sealing contractor, can be sealed. Next, you must treat common walls, floors, and ceilings as you would treat assemblies that separate conditioned space from the outdoors. The codes air barrier and insulation mandatory table/checklist must be applied to these common fire rated assemblies. For example, if there is a tub or shower pan, drop ceiling, or knee wall adjacent to an adiabatic common fire rated wall, floor, or ceiling, an air barrier needs to be installed. Lastly, these details cannot be an afterthought! They need to be addressed from the first design charrette, through a trade partner kickoff meeting, to mid-phase air barrier and insulation rough quality assurance inspection, if there is to be any hope of achieving 3 ACH50 when the home is blower door tested at a final inspection. Blower door testing occurs when the home is complete and when it is impossible to achieve significant air sealing objectives at this point of construction. Small changes in the tightness of the home may be able to be achieved, but air takes the path of least resistance; so if you have not blocked and sealed it out behind the drywall it is unlikely that you will be able to do more that achieve a small increase in the tightness of home at a final stage of construction. In other words, the work has been done at the time of the rough inspection and the evaluation of the work is done at the final inspection.
In conclusion, get involved and take full advantage of EnergyLogic’s third-party inspection and testing services. Get us involved as early as possible in the design of your multi-family project, and let us train all your trade partners at a kickoff meeting, how to successfully work toward meeting the requirements of code. It is not easy, but attention to detail, quality assurance inspection, and greater understanding by the trade base will make 3 ACH50 achievable.
Who to Contact:
Principal, Director of Builder Relations
The 2015 International Energy Conservation code has recently been published and we are seeing some local jurisdictions (Denver and Parker) beginning the process of adopting it. This new code is quite different from previous updates, and we’ve identified three unusual aspects of the code change that you should know about.
1. The actual increase in efficiency from the 2012 IECC came out to only 1.5%
As you may know, I-codes are on a three year development cycle. As we completed developing the 2015 I-code, the 2018 I-code development is starting. This cycle is an issue that the International Code Council (ICC) and jurisdictions are struggling with as some feel they need more than three years to implement and understand the implications a new code, especially as they become more complex. Many jurisdictions were unwilling to adopt recent revisions and are now overwhelmed by what will happen with the 2015 adoption. This was revealed during recent code development hearings in October of 2013. This unwillingness showed efficiency gains from code cycle to code cycle come to a screeching halt with only a 1.5% increase.
2. Not much changed between the 2012 and the 2015 other than cleaning up language and making it more usable
Jurisdictions and Builders who are currently utilizing the 2009 IECC or older will have the most difficulty with a 2012 or 2015 IECC code change adoption. This is because of mandatory requirements needed to achieve the 15% increase in efficiency above the 2009 IECC and the 30% increase in efficiency above the 2006 IECC (see chart above). That being said, jurisdictions such as Denver who are going from 2009 or older versions are jumping directly to the 2015 IECC rather than going to the 2012 first. As noted earlier, the 2015 IECC is a better written code than the 2012 IECC, and it has only tweaked the efficiency requirements rather than advance them another 15%. It is likely that many jurisdictions will skip the 2012 and move directly to the 2015 IECC.
The biggest addition to the 2015 IECC is the inclusion in chapter 4 of an additional compliance pathway through the code. Older versions of the IECC had three pathways one could choose from to demonstrate compliance. These are:
- The prescriptive path:
- This path mandates minimum levels of insulation in the building envelope based off of a component insulation table for each climate zone in the country. A builder can add more R-value than listed in the table but cannot trade off a lower component R-value in a specific location, an attic for example.
- The Total UA alternative or UA path: (area weighted U-value (UA))
- This path allows a Builder to trade off R-values and U-values within the thermal envelop and is most often complied with using the RESCheck software and is sometimes called the RESCheck path. If a Builder would like to put an R-20 in an attic, for example, it would be allowed if the lower energy performance could be traded off for better performance in another component of the building.
- The simulated performance path:
- This path offers the most flexibility for tradeoffs and is the path most EnergyLogic builder clients utilize. In addition to being able to trade off R-values and U-values (conductive energy) this path allows for trading convective energy losses for conductive energy losses and therefore house tightness, duct leakage, ventilation and more are all accounted for in demonstrating compliance.
We are currently teaming with other code experts on writing a white paper that significantly goes in depth on more aspects of this code change. If you are interested in reading that preliminary , please click here.
If you are interested in attending any classes EnergyLogic is offering on the new code, follow this link.
Principal and Director of Builder Relations
- As with all pathways of compliance, the ERI path requires compliance with all the mandatory provisions of the IECC such as air leakage, duct leakage, ventilation, and air barrier/insulation requirements. This means that the air leakage requirement of 3 ACH50 cannot be traded off.
- The ERI path requires the minimum component insulation levels of the 2009 IECC which means that the R-values and U-values of the 2009 IECC become mandatory. You can add more insulation but you cannot trade off for lower component R-values or U-values.
- The ERI is utilizing a fixed Energy Rating Index to help demonstrate compliance with the code. For now the RESNET HERS Index will be what is used. The House will have to meet or exceed the climate zone specific required Index to be code compliant.
As mentioned before, the structure of the IECC requires that, regardless of the pathway chosen through the code, all mandatory requirements in chapter 4 “Residential Energy Efficiency” must be met.
Confusion often arises due to another heading in the code titled “Prescriptive.” Unlike mandatory requirements, prescriptive requirements describe measures that must be accomplished when utilizing the prescriptive and total UA alternative pathways through the code. Although they are not mandatory for all pathways, the prescriptive requirements are often referenced as they embody best practices and are at time referred to in the mandatory sections.
The “Air leakage” section 402.4 of the IECC is mandatory for both the 2009 and the 2015 IECC. However, there are some significant changes in the 2015 version of the code. First, the 2009 allowed a choice between testing the home to achieve less than 7 ACH (air changes per hour) or a visual inspection utilizing the air barrier and insulation table (when utilizing the simulated performance path both of these options were utilized). The 2015 IECC, alternatively, requires both compliance with the air barrier and insulation table, as well as air leakage testing utilizing a blower door. In addition, the 2015 IECC ramped down the air leakage requirement in Climate zone five to 3 ACH, a substantial increase in house tightness. It introduces a new mandatory requirement to ventilate the house properly utilizing whole house controlled mechanical ventilation. This will be brand new to builders coming from the 2009 unless they were using the simulated performance path where house tightness was often used to trade off R-values and U-values in the envelope. EnergyLogic is seeing that by following the 2015 air barrier and insulation table, which was broken out into separate air barrier and insulation columns for clarification in the 2015 IECC, builders are not having any difficulty meeting the 3 ACH requirements in their single family homes. However, Multi-family projects are often struggling to achieve 3 ACH and additional air sealing measures are often needed.
The air leakage section of the 2015 IECC has a significant addition in section R402.4.4 “Rooms containing fuel-burning appliances.” This section now requires a combustion closet or sealed combustion appliances. The change applies to climate zones 3 through 8 and states that “where open combustion air ducts provide combustion air to open combustion, space conditioning fuel burning appliances, the appliances and combustion air openings shall be located outside of the building thermal envelope, or enclosed in a room isolated from inside the thermal envelope.” When a room is used to isolate the appliances from the conditioned space, the room must be sealed and insulated in accordance with the below-grade wall R-value requirement in Table R402.1.1.
Duct leakage testing is another mandatory section of the 2009 and 2015 IECC and there have been changes in the newer versions of the code. Specifically, the 2009 allowed four possible scenarios for testing of the duct system including total duct leakage testing and duct leakage to outside testing at rough or final. The 2012 and 2015 IECC, written slightly differently, moved away from allowing duct leakage to outside testing and now only requires a total duct leakage test if any portion of the duct system is located outside of the building envelope. This is very clear if a portion or all of the duct work is located in a ventilated attic, for example, but is at times difficult to assess if the duct is located within the building envelope such as ducts in a floor system over a garage or an exterior wall in our open floor plans.
Although the early chapters of the IECC do not correspond directly to field construction of the house, they are important to read and understand as the last of the big changes between the 2009 and 2015 IECC occur outside of chapter 4 “Residential Energy Efficiency.” Chapter 1 of the IECC is titled “Scope and Administration.” This chapter includes information that is required on construction documents most significantly:
- R-values and U-values of the thermal envelope
- Mechanical system design criteria
- Duct sealing, duct and piping installation and location
- Air sealing details
- And section R103.2.1 building thermal envelope depiction. “The building’s thermal envelope shall be represented on the construction documents.”
Chapter 1 also includes section 104 “inspections”. In this revised section of the 2015 IECC a detailed description is given on the type of inspections that are required including footing and foundation inspection, framing and rough-in inspection, plumbing rough-in inspection, mechanical rough-in inspection, final inspections, and re-inspections.
Chapter 2 “Definitions” includes some new terms such as circulating hot water system which was needed to help describe an entirely new mandatory section of the 2015 IECC R403.4.1 “Heated water circulation and temperature maintenance systems.” I did not discuss this in this article as the provisions are only mandatory if a hot water circulation system has been installed. In addition, definitions of terms used in the Energy Rating Index path were added to this chapter.
Chapter 3 includes the addition of a new tropical climate zone as well a better defined requirement that the insulator “shall” provide a certificate listing the manufacture and R-value of installed insulation in each component of the building, as well as, the installed density for wall and attic blown insulation and coverage area, installed thickness, settled thickness and R-value of blown attic insulation. “The insulation installer shall sign, date, and post the certification in a conspicuous location on the job site.” I am highlighting this here as we recently learned that insulation companies are installing wall insulation at different densities to achieve different R-values. It was standard practice to insulate a 2×6 wall with blown fiberglass to an R-23. Now, based on the density of the installed blown in product builders can be receiving anywhere from an R-20 to an R-24. Unfortunately code and quality assurance inspection cannot visually identify the R-value of the assembly. We therefore recommend that builders include language in their scope of work documents requiring the creation and posting of a completed insulation certificate as well as the posting of results from at least 4 density tests per home. This should ensure your installation is meeting your specifications.
Lastly, there are a couple new sections of the code that should be touched on.
- Chapter 5 is a new chapter that explains how the energy code “control (s) the alterations, repair, addition and change of occupancy of existing buildings and structures.”
- For the first time the IECC will have two new appendices. The first involves recommended procedures for worst-case testing of atmospheric venting systems (combustion safety testing). The second is a solar-ready provision for detached one and two-family dwellings. Appendices are not mandatory unless an adopting jurisdiction makes it so.
So after analyzing the 2015 IECC you will notice that the actual impact to energy efficiency is minor compared to the changes introduced in the 2012 IECC. If jurisdictions are moving to a new energy code it will only impact you if that jurisdiction is moving from the 2009 or earlier version of the IECC and if a builder has not had any experience working in a jurisdiction that is currently on the 2012. The 2015 IECC truly represents a break in the process of ramping up requirements and efficiencies to make the code more stringent. It is a better written version of the 2012 IECC which added a unique compliance path utilizing the Energy Rating Index.
Time will tell if this is a trend in the code development cycle or not.
Principal and Director of Builder Relations