All New Homes
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
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
EnergyLogic is proud to announce some exciting changes to our team! Get to know our new Field Services Manager & Software Technical Liaison, Steve Eagleburger.
Q&A: Learn more about Steve, his comprehensive background, and credentials!
What was your first job in the residential construction industry?
I’ve been involved in construction most of my life. I started as a painter/faux finisher around 30 years ago. I moved on to handyman work and eventually became a General Contractor around 2003.
How and when did you first become interested in high-performance homes and energy efficiency?
I’ve always been interested in environmental construction and design. I built the one and only Compressed Earth Block home in Denver and currently live there. It’s imperative that the construction industry realizes the impact it has on this planet and its inhabitants and take steps to move toward more efficient, cleaner and safer homes.
What insights did you gain in your time working as a general contractor?
Contractors can change the way we build homes and by making that change we can create longer- lasting, more comfortable, better performing homes. We often are focused on the bottom line when we should step back and look at the big picture. Success comes when we meet a triple bottom line -Economic Value, Environmental Sustainability and Social Responsibility. This is what drove me as a G.C. and eventually what lead me to work at Energylogic.
You’ve been with EnergyLogic since 2010 and have worked at a number of different roles. What are some things you can share about your background in residential energy consulting?
You don’t know what you don’t know until you know it and as soon as you know it you need to share it. This is a constantly evolving industry and as raters and builders, we have to stay informed. Codes and programs evolve over time. It’s our responsibility as energy consultants to keep our clients informed and be as pre-emptive as possible when change is coming. Nobody likes surprises!
What are some of the common design mistakes or misconceptions builders should watch out for?
Demand a detailed set of drawings from your architect and engineer before you start to build and make sure those drawing specify local codes and builder program details! Refresh your plan set to include updated codes or details that were missed originally so you don’t keep repeating the same mistakes. So many failures and re-inspections can be avoided by having a knee wall framing detail somewhere in your plan set, or air barrier detail drawn for double framed walls, or by making sure there’s room between the stairs and foundation wall to add insulation, etc. These details allow everyone to do their job better, from estimators to installers.
Little things do matter. Even though we don’t like to delay construction schedules over minor issues, small improvements on a national scale can make an impact. We call these things out to help you build a better product, not to be obstructive. The building code and national programs such as Energy Star and DOE Zero Energy Ready Homes exist to help you build a better product and get to that triple bottom line. Embrace it and accept the future of construction!
What do you like to do in your free time?
When I’m not working you’ll find me hiking or camping with my wife and dog, but nothing too extreme. We like the quiet places. Or maybe I’m down at the local brewery for a pint of cask-conditioned English ale. Once a week you’ll find me at Zenko Kyudojo in Boulder, practicing Japanese archery.
EnergyLogic Academy’s Referral Program Rewards – Tell ALL Your Friends!
We feel everyone should benefit from ‘word of mouth’ marketing, not just us! We make it worth your while by offering cash rewards through our referral program.
Let’s keep building this industry – together!
RESNET HERS® Rater Training Combo Package (Phase 1 & 2)
Phase 1 of the EnergyLogic Academy HERS Rater training is designed to allow participants to navigate through the knowledge base needed for a HERS Rater at the users own pace. The course prepares students for the extensive knowledge needed in building science, building materials, integrated construction processes, HVAC equipment, and diagnostic testing equipment and processes.
The HERS Rater Training online course covers the core knowledge for the HERS Rater certification. By enrolling in our self-paced, open enrollment course, you will have 90 days to complete the training. You can complete the training at your own pace, and you do not need to use the whole enrollment period if it is not needed. There are 24 modules in the course – each module will take a minimum of two hours to complete, with some taking over four hours.
Phase 2 is four days of field training designed to introduce the HERS Rater inspection processes and diagnostic testing. During the field training, we will complete two practice ratings according to the RESNET training standard. Practice ratings will be performed on an existing home and a new home.
This is an instructor-facilitated course. Students will have one-on-one instruction with the testing equipment. Much of the field work will be done in a group setting, where peer-to-peer interaction is used to complete the practice ratings.
RESNET® Instructor, Green Rater, Auditor
Field Services Manager & Software Technical Liaison
After completing the course, Rater candidates have two steps remaining before earning certification:
The candidate must pass three exams. The exam fees are not included in the price of tuition. These fees are paid directly to RESNET. For more information click on the RESNET Exams tab.
The candidate must join a provider and complete the probationary phase of certification. The provider ultimately issues the certification once the candidate completes the probationary phase.
A package you just can’t turn down!
Use coupon code december2016 for $500 off of the HERS Rater Training Como
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.
It would be an understatement to say the housing market all across Colorado’s Front Range came out of the gate strong. EnergyLogic’s first quarter of 2016 has been our busiest ever, and I have been in the field more these last few months than I have in the last five years combined. As Field Services Division Director, it seems my career has come full circle. Turns out that running a blower door is a bit like riding a bike- your top speed might slip a bit as you get older, but you never really forget how to do it. But my perspective sure has changed- now I see everything through a manager lens. I notice things about the entire operation, the sequencing, and how superintendents spend their time differently than in the past.
The other day I was struck by the contrast in jobsite cleanliness between two separate communities I visited on the same day. My mind automatically went to cost-benefit analysis. What is it costing the builder with the clean jobsite to keep it that way? How are they accomplishing this when construction is inherently such a messy business? Are they hiring day labor to clean up, or just giving their superintendents time to walk their homes and enforce the expectation that each trade cleans up after itself? Either way, there is a cost. What benefits are they getting for that added cost? Based on my own experience, and a bit of research, I’ve come up with my own short list.
Without further ado, here is my own Top Four Benefits of a Clean Jobsite:
1. Safety – “A clean jobsite is a safe jobsite” – you’ll hear this quote in many OSHA trainings, and the truth of it is pretty obvious. Clutter and debris create tripping hazards and may hide other dangers such as electrical or fall hazards. Keeping things cleaned up makes the site safer for everyone- from the workers to the occupants of finished homes nearby. The other day I moved a four foot sheet of scrap osb which was lying nails-up on the sidewalk – this on a street where half the homes were occupied!
2. Efficiency – This is half the reason I was inspired to write on this topic. There was a noticeable difference in my time on-site for what (on paper) looked like two identical inspections. The clean site was quicker to inspect and my duct test even went a little more smoothly since there was no debris hiding any of the supply or return registers. It certainly helped that the work I was there to inspect was ready and correct. But that’s a topic for another article…
3. Attitude – This one is a little harder to measure, but I can say that my own attitude was better on the clean job site. And my experience tells me that messy job sites also tend to be the ones where I find sloppy work that fails our inspections. Whether the messy jobsite is a contributing cause or just another symptom of a larger problem is unclear. But there is certainly a corollary. It’s easy to see where a tradesman showing up to an already messy jobsite would get the signal that cleanup is optional and sloppy work is tolerated.
4. Be the Employer of Choice- Most builders have heard this buzz phrase lately. It certainly becomes an important issue when consumer demand is up and skilled labor is tight. In doing a little research for this article, I was somewhat surprised to find that building consultants (through many interviews with tradesman across the U.S.) have found that being paid top dollar is not at the top of the list of things that made them prefer one builder over another. Conditions that allowed them to get in, complete their work, and get on to the next job efficiently ranked at the top. Of course, having the necessary materials delivered on-time and being able to count on things being ready on their scheduled day are the largest part of this (ie: no dry runs). But as stated above, a clean site also improves workers’ efficiency. Let’s face it, when you don’t have to work around somebody else’s mess, you can get your own job done more efficiently. For most tradesmen, getting on to the next job more quickly is the best way to increase your take.
On December 18th, 2015, during the closing hours of the 2015 legislative session, President Obama signed into law the extension of several expired tax provisions, including the 45L $2000 federal tax credit for high-performing energy efficient new homes. You may remember that the $2000 tax credit expired on December 31, 2014. This new legislation made the tax credit retroactively available for homes built in 2015 and extended it for homes built in 2016.
Unlike the last reauthorization of this legislation, no changes were made to the requirements for a home to qualify for the tax credit. The last reauthorization changed the basis of the tax credit from the 2003 to the 2006 International Energy Conservation Code. We learn that this change has made it significantly more difficult to qualify. That being said, we continue to believe that it does not make sense for builders to make a specification change in an effort to capture more tax credit dollars, unless we know that the credit will be extended beyond 2016. If you would like us to run an analysis on your homes to identify what specification changes would lead to higher compliance, we will be happy to do that though our consulting services.
How the Tax Credit works:
Many may not remember how the tax credit qualification is actually quantified. Your house is imputed into the modeling software tool. Within that software (REM/Rate) the house is duplicated, thus creating two houses that are geometric twins; House A and House B. House A is assigned the energy specifications that are outlined in the 2006 IECC and House B is assigned the energy specifications you, the builder, actually used. The tax credit is issued for House B when it is 50% more efficient in heating and cooling energy use than House A, built to the 2006 IECC. For the modeled “House,” the software determines what the 50% target is and if the as built house (House B) is performing equal to or better than the 50% targeted energy use.
The tax credit adds one further complication in that it has created a two-part test to demonstrate 50% compliance. The home’s heating and cooling energy use must be 50% more efficient than the 2006 IECC, as measured by normalized end-use loads and the building envelope component loads. The building envelope component loads alone must account for at least 10% of those savings. If both of these tests pass, the house qualifies for the tax credit. According to the software compliance reports, a majority of homes pass the envelope loads test but do not always pass the normalized end-use loads test. Normalized end-use loads account for the differences in equipment types that exist when using gas or electric utilities. This is a bit of a ‘black box’ calculation; this portion of the compliance matrix has to be addressed by a specification change in order to capture more rebates.
Only homes that are tested and inspected can qualify for the tax credit. While we can do some analysis to help increase the percentage of the homes that will qualify, it is unlikely that 100% of your homes will ever qualify. This is because the analysis utilizes a whole-house evaluation and some of the parameters are not in the builder’s control, such as house orientation.
In order to claim the tax credit, you will need the tax credit certificate from us and IRS Form 8908.
On February 20th 2015, the program shifted from rebates based on a HERS index score to rebates based on the percentage improvement over above code in which the home resides. The HERS ratings will determine the percentage above code using a matrix on millions of BTU’s. The ENERGY STAR certified home label is now a bonus rebate category and available to any home that earns the certification. EnergyLogic will continue to enroll your home in the program and provide all required documentation needed to process the rebate.
How your home is assessed
In addition to complying with the requirements of the Energy Star Thermal Enclosure Checklist, EnergyLogic will use a software modeling tool, to compare the as-built home’s energy consumption to that of a reference home built to meet the minimum code requirements in your local jurisdiction. The energy savings, as measured in MMBtu’s, between the as-built home and the reference home is converted to a “better than code percentage.” The more energy-efficient the home is, the greater the code percentage and the larger the rebate will be. The HERS index score is no longer used to determine the rebate award, but it’s a valuable tool for you to communicate the home’s efficiency to potential home buyers. And it is a piece of the information that Xcel requires of us to complete each homes rebate process.
Currently, homes built in 2009 IECC jurisdictions will have no difficulty meeting a rebate category. Those built in 2012 or 2015 IECC jurisdictions, however will have a more difficult time. Many of the homes are qualifying at just 10% better than the code, so if you would like to increase your rebate payment amount please contact EnergyLogic. We can model your homes and identify what cost effective measures may be available to increase your energy specification to bring you a larger incentive.
ENERGY STAR-Certified Bonus Rebate
Homes that meet the following criteria are eligible to receive a bonus rebate of $100 from Xcel Energy, in addition to the Performance Rebate.
- The home must have both Xcel Energy natural gas and electric service in Colorado; and
- Qualify for a “Percent Better Than Code” rebate; and
- The home must earn the ENERGY STAR label under all EPA guidelines at the time of certification via the performance path, and the ENERGY STAR label must be applied to the breaker box.
Additional ENERGY STAR Appliance Rebates
Builders who are eligible for the Xcel rebate can also receive a rebate for installing any combination of ENERGY STAR -qualified appliances and lighting. Homes that receive only natural gas service from Xcel Energy are not eligible for the ENERGY STAR refrigerator or Lighting Efficiency rebate.
EnergyLogic will confirm that the appliance is installed during our final inspections, and will document the model specifications. The information will then be submitted to Xcel Energy on your behalf for rebate.
Contact Robby Schwarz with any questions. 720-838-0677
Black Hills Energy has come out with a new program for builders in 2015. The program requires the home to be located in Black Hills Energy gas service territory with installed gas heating system as the primary source of heating. Homes must be completed between Jan. 1, 2015 and Dec. 31, 2015 and applications for rebates must be received by Jan. 31, 2016.
Additional mandatory requirements for the Black Hills Program include the following minimum efficient equipment:
- 94% AFUE for furnaces
- 67 EF water heater
Lastly, builders must choose either a prescriptive or a performance path..
For the prescriptive path, rebate item must be chosen within each equipment type category. Each category indicates how many measures must be included. Each choice has an associated rebate value.
The Performance path utilizes a Home Energy Rating to determine if the home performs at a minimum 10% better than the local code jurisdiction in which the house resides. The incentive for this pathway is capped at $1000.
Before deciding on a pathway through the rebate program it is recommended that you consult with EnergyLogic in order to determine which pathway is the most effective in returning incentive dollars to you. In most cases the prescriptive path is the most fruitful – even if you are currently utilizing the performance path for code compliance, HERS Ratings, and building to ENERGY STAR.
Contact Robby Schwarz with any questions. 720-838-0677