Here is the text version of the ZERH webinar “Single Family Version 2 Training,” presented in April 2024 by the U.S. Department of Energy’s Building Technologies Office.
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Devin Neil:
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Welcome to the U.S. Department of Energy Zero Energy Ready Home program training on its Single Family Homes National Version 2 program. My name is Devin Neil and I'm the program account manager. This training is designed for all partners interested in pursuing ZERH certification under the Single Family National Version 2 program requirements.
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Please note that while this training is available to all partners on the ZERH website, raters and verifiers need to take this and other required training through their Home Certification Organization, or HCO, for ZERH so that they may track your participation. Watching this training via the ZERH website does not fulfill the training requirements for raters and verifiers. I will now pass the presentation over to Jamie Lyons, the technical director for the program.
Jamie Lyons:
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Great, thank-you, Devin, and thank-you, everybody, for taking some time to review this recorded webinar on Zero Ready Single Family V2 and increase your understanding of the program. And we look forward to working with stakeholders under the Zero Ready Single Family V2 program. Here's the overview of what we'll cover in this session. We'll talk about the program structure and some of the key components. We'll walk through each of the mandatory requirements for Zero Energy Ready Home Single Family Version 2, and then I'll hand it over to my colleague, Sarah Cok, the technical manager for the program, to walk us through the target home and how that works. We'll speak a little bit about certification process and then we'll wrap up with a quick review.
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So first off, in the program structure, we'll cover a couple really key components including the building eligibility and how different program versions become effective and how the timing works for that.
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So Single Family Version 2 of the Zero Ready program includes single-family homes, townhomes and duplexes as the eligible building types. And important to note, this is the exact same eligibility criteria as you'll find in the ENERGY STAR single-family new homes program. I'll also note that Zero Ready Single Family V2 does not apply to multifamily buildings nor to manufactured homes. But there are indeed Zero Ready program versions available for these building types. And there are two types of Zero Ready Single Family V2 program requirements. One is what we call national, which applies to all states except California. And then the second is a set of California-specific requirements that achieves a similar level of energy efficiency to Zero Ready national, but it's more aligned with the California energy code. So I just want to point out today's training is not covering the California specifications. However, there's certainly more information available on those specs on the Zero Ready website.
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The program requirements are structured into a set of mandatory requirements and then a performance threshold. So the mandatory provisions ensure that they're really important, must-have features will indeed be included in each certified home. And these are the types of measures that are really considered essential for the home's performance. And there's also typically a big opportunity cost of missing them during initial construction. One example that is getting a really well-insulated building envelope, which is much more effective done during the initial design and construction.
And then also the performance threshold in that middle column, that sets the bar for the energy-efficiency level that the home must meet, the efficiency levels demonstrated through the use of energy modeling software. And there's a lot of customization and flexibility here. So that threshold can be met using a variety of different energy-efficiency measures that collectively will meet the threshold. And we'll talk more about that further along.
And then lastly, on the right side there we can see that compliance with these requirements is verified using rater checklists that are going to be completed by a third party, and they serve to support and document the home’s certification.
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So this chart that we see here, which you'll also find on the Zero Ready program website, identifies the different implementation dates for the Single Family Version 2 Rev 1 program requirements. To determine the appropriate set of requirements to use for a given project, you'll need to know its building type, the permit date and the location.
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So here we can see that Single Family Version 2 Revision 1 is required for all single-family projects with permit dates on or after January 1, 2024, except of course for those in California. And we'll also note that this chart will be updated over time on the Zero Ready website as new revisions to program versions are released.
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Because the Zero Ready program version is determined by projects permit date that the concept of permit date is very important to understand and how it's defined. So in the case of Zero Ready Single Family V2 program, the permit date is defined as it as it's shown here on the slide, which is the date on which the permit authorizing construction of the building was issued. Alternatively, the date of the rater’s first site visit or the date of the contract on the home is allowed to be used as the permit date. So those provisions in the definition of permit date are found in each set of program requirements, and they're important to understand because they're sort of the trigger for when a program will be implemented. We'll also note that revisions represent updates to a program version. And we also want to note that newer, more recent program versions and revisions can optionally be used by partners earlier than when they're required.
And also as a project is certified under a newer program version or revision, it's also deemed to meet the certification requirements of corresponding earlier or older versions and revisions. So for example, a home that meets Zero Ready Home Single Family Version 2 Revision 1 would also be deemed to meet the certification requirements of Zero Ready Single Family Version 2 Revision 0.
And then finally, the project must be certified under just one program version revision. So it's not permitted to take parts of one program version and mix them with parts of another program version. Everything has to be certified under a single program version and revision.
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This slide covers Zero Ready homes and the 45L tax credit. So in August of 2022, the Inflation Reduction Act was passed, which amended the 45L tax credit to provide credits for ENERGY STAR and DOE Zero Energy Ready certified homes. Homes certified Zero Ready can earn up to $5,000 per home, and in order to be eligible, the home must be acquired between January 1, 2023 and December 31, 2032. So there's a much longer runway for the 45L tax credit with this recent update from the 2022 IRA legislation. The Zero Ready program version required for 45L is the same Zero Ready program version that's required for certification. And we figure that out based on the chart that we just reviewed previously and that's also posted on the Zero Ready website.
And also wanted to note that there's a web page titled “45L and Zero Energy Ready” on the ZERH website with further information about the 45 L tax credit, including links to IRS resources.
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Next, we'll walk through each of the mandatory requirements for Zero Ready Single Family Version 2. And I wanted to note that the level of detail on these slides is what we would call moderate. So we're giving a good sense of each requirement, but not necessarily every last detail. So as teams develop specs for the Zero Ready projects, it is important to review the actual program requirements just to be aware of any details that might be relevant to the project.
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The first place to look for information on the program's requirements is the document posted on our website titled “DOE Zero Energy Ready Single Family Version 2 National Program Requirements.” And we see a little snapshot of that here. And that's the first exhibit that you'll find in the program requirements. We'll call it the NPRs. And it lists all the mandatories, and that's what we'll walk through over the next few slides.
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So here we'll do a quick snapshot of what the mandatory requirements are at a high level, and I'll walk through each of them with some subsequent slides. So there's a couple corequisite certifications. There's an envelope requirement, high-performance window specs, provisions for ducts and air handlers to be located in conditioned space, provisions involving our water heating system efficiency, lighting and appliances. Indoor air quality is a key piece. And there's four readiness provisions, heat pump, space heating readiness, heat pump water heating readiness, PV readiness, and electric vehicle ready.
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So that first piece is a really good starting point. And this is the requirement for two prerequisite certifications, ENERGY STAR and Indoor airPLUS.
So Zero Energy Ready Single Family V2 builds upon the ENERGY STAR Single Family New Homes Version 3.2, which is a prerequisite requirement for Zero Ready Single Family V2. Additionally, there's a prerequisite requirement for each project to certify under the Indoor airPLUS, or IAP, program. Currently, the requirement is for project to certify under IAP Version 1 Revision 4, like we see here on the slide, until at least 12/31/2025, and the Zero Ready program is also planning to update this prerequisite requirement for Indoor airPLUS to reference Version 2 certified tier no earlier than 1/1/26. And we advise partners to look for more information on this requirement as the Indoor airPLUS program finalizes its IP specs and releases the Version 2 specifications in 2024.
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Next mandatory requirement in exhibit 1 of Zero Ready covers the building's exterior envelope. By getting the envelope right, as we mentioned earlier, is a really critical piece during the home's initial construction. It will reduce the energy load for both heating and cooling, resulting in lower bills. High-performance envelope also will keep temperatures more consistent throughout the house, reduce drafts, and can provide a comfortable environment even during periods of extreme heat or cold outdoors. And we've heard from partners that even when the power goes out, homes with a Zero Ready envelope can stay comfortable for longer periods of time compared to standard homes. And we can see here a nice customer testimonial of the comfort experience of living in a home with such a robust building envelope.
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So homes achieved this high-performance envelope in part by meeting the insulation requirements in the 2021 IECC, or International Energy Conservation Code. Previously, Zero Ready had referenced the 2015 energy code for envelope insulation levels. And here in the chart we can see that the values highlighted in yellow represent areas where the ‘21 code has increased the energy efficiency provisions for the envelope. So there's some for the ceiling, some for wood-framed walls and climate zones 4 and 5. And if you increase insulation levels for slab insulation as well. So homes may meet or exceed these levels using what's called a UA calculation, which allows for tradeoffs between different building envelope components. Energy modeling software programs typically include a UA calculation.
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So the building UA is calculated by multiplying each envelope’s component surface area by its respective U factor, adding them together, and then dividing by the total envelope area. So in this way, for example, if a design features a ceiling and windows that are more efficient than the code requirement, which is going to mean a lower U factor, and we can see that in the pink boxes here, but the same design has walls that don't quite meet the minimum prescriptive levels in the 21 code, meaning a higher U value, when we add these things up and consider the relative sizes of the different components, it can still achieve the same UA as a design that meets the exact code required levels, which are shown in the light green boxes here for an example project in climate Zone 3.
And while we don't show the full calculation here, there's really two important takeaways about using a UA calculation to meet this envelope provision. First off, tradeoffs like this provide the builders with a level of flexibility in their design, at the same time assuring that we get a high-performance thermal envelope. And then secondly, modeling software is easily used to assess different design strategies. So builders and their teams can easily do some scenario testing, looking at different strategies for envelope insulation that at the bottom line will meet the 2021 UA and therefore meet the Zero Energy Ready requirement.
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In addition to the total envelope requirements that we just looked at, Zero Ready also has specific high-performance window requirements. It's critical to establish some minimum window performance levels so that we don't end up with very well-insulated envelopes and walls, but with windows that are still losing a lot of energy and can potentially create comfort and condensation issues. We see here another homeowner testimonial reinforcing the connection between comfort and high-performance windows.
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The table shown here show the required U and solar heat gain coefficient, SHGC, values for Single Family Version 2 and they're broken down by climate zone. And also note that these windows are attainable with many good window products in the market. And we see some builders actually using more efficient windows than these minimum backstops. And when they do so, they can use that additional efficiency in in their UA calculation and use it as a tradeoff component in other areas of the building envelope.
And then one last quick note for projects that are located at high altitudes, for those using passive solar designs, the program offers alternate window criteria, and we'd advise you to check out the national program requirements for more details.
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Locating forced air distribution ducts in the air handler within conditioned spaces is another key design detail to get right during initial construction. When ducts and air handlers are located in much more severe environments, there's going to be energy and performance penalties that result from that, which likely will remain in place for the life cycle of the home. Those are hard things to change.
So for example, the first picture here on the left shows an example of not locating ducts in a conditioned space, but instead locating them up in an attic space where the cool air that they're delivering in the summer might be exposed to triple-digit heat. And leaky ducts in unconditioned spaces can also draw in indoor air quality pollutants and then distribute them in the home.
On the flip side, that the next picture that we show here on the right is a duct system that's been designed to route through the building's ceiling and floor framing. And routing ducts through the building cavities like this becomes a little more feasible in high-performance homes because these homes are going to have much better envelopes, lower heating and cooling loads, so there's less air to route to meet those loads and therefore smaller ducts, which can more easily find adequately sized spaces to be routed through building cavities.
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So this slide shows the actual Zero Energy Ready requirement, and we'll point out that there are quite a few strategies builders can use to accomplish the spec, which are shown here on the next slide.
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So each of the design strategies here would satisfy the Zero Ready requirement for duct location. Over on the left side, we see mini-split ductless systems that simply don't have ducts to route, so those are a good fit. Ducts can also be located under the attic insulation in a vented attic. We'd suggest looking at the program requirements for more specifics on how deeply they need to be buried and how tightly those ducts need to be sealed. And then over on the right side, we see several other options to keep ducts within the home's thermal envelope. And there's different pros and cons to these different strategies and methods to make each of them really work as effectively as possible in terms of the installation process, design and aesthetics. And our builders will arrive at different strategies depending on what works best for them. And we'll also note that this provision requires both ducts and the air handler to be located in conditioned space. So some of these strategies such as the insulated basement or an unvented attic also provide that space for the air handler to be located in the same space.
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Next up is water heating energy. It's a major energy end use in homes, often being the second or third largest end use. And as the pie chart over here on the right shows, water heating makes up 18% of total U.S. residential energy consumption. So it's a big end use in homes. So the water heater efficiency is certainly an important aspect of this system, along with the distribution for delivering that hot water throughout the home. And this is an area where many high-performance builders can sometimes find some performance gains once they focus on hot water distribution.
Some of the benefits of an overall efficient water heating system include saving a lot of energy used to heat the water, in addition to saving a lot of water because homeowners don't let a lot of water just run down the drain waiting for hot water to arrive. And there's also a lot of upstream energy that goes into water sanitation and distribution. And that that represents additional savings that can be realized.
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So the Zero Ready V2 program offers three different options. So it's an A, B, or C type of provision for achieving an overall efficient water heating system.
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The first option is to design the hot water distribution system to be very compact, so that very little water volume, a half-gallon or less, is stored in the distribution system between the hot water source and the fixture that's furthest from that source. So in most cases, when we say source, we mean the water heater, unless there's a recirc loop, in which case the source is the point where the branch take off leaves the loop and runs out to that furthest fixture.
The second option is shown here, involves providing an overall highly efficient water heating system with a few different components. That first component is going to be a very efficient water heater, and if it's gas, we're talking a uniform energy factor, or UEF, of at least .87, which is going to mean a tankless system. And if it's an electric water heater, it's a UEF of at least 2.2, which will mean a heat pump water heater. Also, it's a well-designed distribution system that contains no more than 1.8 gallons of water stored between the hot water source in the first fixture. And finally, it requires the use of water conserving fixtures, which means WaterSense-labeled showerheads and bath faucets.
And then the third option is for the home to be certified on the EPA's WaterSense 2.0 program. This ensures that the home's overall design conserves both water and the energy used to heat water. Zero Ready builders already participating in WaterSense will often find this to be a good option for them.
And just lastly, we wanted to note that for the first two options where there's that stored hot water volume component, to verify that stored volume limit, verifiers can use either a plan takeoff method or a field measurement method. There's details on that in the program requirements, but just to point that out because that's a question that will often come up.
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The next mandatory provision looks at efficient lighting and appliances for Zero Energy Ready Homes. As we design homes to be Zero Energy Ready, it makes sense to just continually reduce the energy use of the overall home in ways that are effective and take advantage of all the opportunities to do that. And as these pie charts show, over the years, overall energy use in the home has reduced. We have a smaller pie. But that yellow slice, which is the piece connected with lighting and appliance energy use, it's become proportionally larger. So it makes sense to address appliance and lighting energy use as much as possible.
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So Zero Ready Single Family Version 2 requires ENERGY STAR refrigerators, dishwashers, clothes washers, clothes dryers, and bath ventilation fans, only in cases where the builder supplies and installs that appliance. And for lighting, the program is now at 100% LED lighting with just a small allowance for specialized lighting, up to 5% to be non-LED, only for limited applications. And even if that exception is used, the overall efficiency target for the home assumes full-on 100% LED's. So any little loss of efficiency with non-LED lighting will need to be made up elsewhere in the design. And we also note that LED requirements don't apply to lighting pictures that are part of appliances such as an oven light or fridge light.
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Indoor air quality and a healthy indoor environment are really critical benefits for residents of Zero Ready homes. And the program views indoor air quality as really a critical and essential component. It's not an extra; it's a very core component of the Zero Ready program. And additionally, a lot of Zero Ready builders find that IAQ is really a critical sales feature buyers are looking for in their new homes. And as the homeowner testimonial on this slide demonstrates, high-performance Zero Ready homes can really make a powerful difference in how residents feel, such as this case for one of the residents of a new Zero Energy Ready Home saw remarkable improvement in their asthma symptoms.
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So Zero Ready Single Family Version 2, as we mentioned earlier, requires compliance with the EPA's Indoor airPLUS certification program, which is a complete package of IAQ protections. Some of the key provisions in Indoor airPLUS include properly sized and designed ventilation systems, pest management features, combustion safety provisions, the use of low-emission materials like paints and carpets to reduce exposure to VOCs, radon-resistant construction techniques and provisions to control moisture, both bulk moisture and water vapor in and around the home. And just to reiterate, currently Zero Ready Single Family Version 2 requires compliance with Indoor airPLUS Version 1 specifications. IAP is in the process of updating to Version 2 program with enhanced and updated IAQ provisions, and the Zero Ready program will also update its IAP requirements, require Indoor airPLUS Version 2 certified tier no earlier than January 1 of 2026.
Additionally, there's one other requirement revolving around IAQ, the Zero Ready program, which is the use of heat or energy recovery ventilator in climate zones 6 through 8. These are really cold climate zones where the heat exchange capability of this technology boosts the efficiency of providing ventilation to the building.
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OK, moving into our readiness provisions, Zero Energy Ready Homes are made ready for four critical innovations that homeowners might end up using on day one in their new homes or at some point in the future. These innovations revolve around clean energy technologies that make a home more efficient to operate as well, and Zero Energy Ready Homes are designed to accommodate them. So the graph over here on the right shows that U.S. electric generating capacity from renewable energy sources has been growing very quickly in the U.S. and it's projected to continue along that trend. The readiness features included in Zero Ready are positioning homes to leverage high-efficiency electrical technologies as the U.S. electric grid significantly increases the supply of clean electric power. So these readiness provisions consist of PV readiness, heat pump heating readiness, heat pump water heating readiness, and electric vehicle readiness, which we'll cover on the next four slides.
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First, Zero Energy Ready includes photovoltaic readiness provisions that prepare homes without solar today for more streamline installation in the future. There are four simple parts to the Zero Ready PV readiness provisions. First, the maximum allowable dead and live load ratings of the roof are documented and provided to the owner so that a feature PV installer has this information available for use in a future PV design. Next, the potential location for the arrays proposed and documentation of this location is provided to the homeowner. Conduit is run from the attic area beneath the proposed PV array location to a location within eight feet of the electric service panel. And finally, spaces provided in the panel for a dual pole circuit breaker to be installed and used with the PV system in the future.
Also a few exceptions, four exceptions which exempt at home from having to complete the PV ready requirements. They are: if the home already includes on-site solar, if the home receives energy from a community solar system, or it's naturally shaded, or does not have enough free roof area for a PV array, then it can be exempted from the PV ready checklist provisions. The program requirements list the exact details of when these exceptions apply. It's also important to note if the exceptions do apply then the home can still be certified under the Zero Ready program as long as it meets all the other applicable program requirements.
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The second readiness requirements are for the installation of a future heat pump in homes where gas is initially used as the primary heating source. So to prepare for a future heat pump installation, there must be either an individual branch circuit or conduit installed, terminating within three feet of the existing gas furnace and labeled for future heat pump. And there's one exception to this readiness requirement. If the home already includes an electric heating system as the primary heat source, then the heat pump readiness provision is not required.
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The third readiness provision covers heat pump water heating readiness. There's two submeasures included as part of this requirement. The first is that there must be a space large enough in the home to accommodate a future heat pump water heater, which for the purposes of this provision is estimated at three feet by three feet by seven feet tall. And this space can include the existing water heater.
Secondly, there must be an individual branch circuit installed and energized, and it must terminate within three feet of the installed gas water heater. The circuit must have a rating of at least 240 volts 30 amps or 120 Volt 20 amps.
And also there are a couple of exceptions noted here on the right. The exceptions apply to the space and circuit provision separately. First, the circuit is not required if the existing water heater already has an individual branch circuit meeting those ratings of 1/20/20 amp or two 40/30 amp. And secondly, the space provision isn't required if the installed water heater is either an electric water heater or gas tankless.
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The final readiness requirement is for electric vehicle charging. So when a private driveway garage is provided for the home, a powered 30 amp receptacle is located either within the garage or within six feet of the private driveway as shown here, and the panel identifies the branch circuit as electric vehicle charging. There's a few instances, however, where these provisions aren't required. First off, if adding the 30 amp branch circuit to the main panel increases the electric service capacity up to the next nominal size, then connecting the circuit to the panel isn't required. Secondly, if there's no parking provider for the home, either private or shared, then this branch circuit isn't required. There's also two more exceptions for scenarios when the local utility infrastructure can't support the additional load. They're a little more detailed, so we reference them and would point you to the program requirements for more details. And then lastly here and there in highlight, for projects with shared parking associated with the residences, there's different alternate EV ready provisions in the program requirements that should be referenced.
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So that's a quick walk through the mandatory provisions and including the requirements involved and some of the options for satisfying those requirements. And now we'll walk through the target home requirements, and for that information, I'll hand it over to Sarah Cok, technical manager of the DOE Zero Energy Ready Home program.
Sarah Cok:
So now that we've covered the mandatory requirements, the other core ZERH requirement is the performance threshold. This threshold sets the bar for how energy efficient a home must be to meet the program criteria.
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To establish this threshold, the Zero Energy Ready Home program uses the target home system that is built into energy modeling software. The software will automatically configure a target home based on the actual design home. This target home assumes certain efficiency specifications, which are identified in Exhibit 2 of the Single Family Version 2 program requirements shown here. The design home must meet or exceed the overall efficiency of the target home. Aside from the several mandatory requirements discussed previously, homes can meet this efficiency target with whatever combination of efficiency measures works best for the builder. Allowing tradeoffs through energy modeling is one of the ways ZERH provides flexibility in meeting its rigorous energy savings requirements.
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The performance threshold is expressed as an Energy Rating index, or ERI, target. The energy rating index is an efficiency scoring metric used widely in the residential construction industry. The lower the score approaching 0, the more efficient the home. The ZERH ERI target will be different for every home depending on its specifications, location, and orientation. The design home is configured by energy rating software, which is reviewed and approved by DOE and will automatically generate the ERI target score. This is the score that the design home has to meet or exceed.
In general, ERI target scores for ZERH Single Family Version 2 are in the 40s, but it's really important to model a particular home and understand how the target score relates to the actual design home ERI score. It's also important to note that while DOE encourages the installation of solar where it is practical, ZERH is currently an efficiency first program, so the design home must achieve this score with efficiency measures. Any reductions in the design home’s ERI score resulting from renewable energy don't count towards meeting the ZERHERI target.
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So here's an example of a ZERH design home, the actual home being built, and its corresponding target home to illustrate how a design home can use tradeoffs to meet the efficiency level of the target home. The target home, built automatically by the software based on the design home inputs, is nearly identical to the design home, except it is configured according to the Exhibit 2 efficiency specifications in the national program requirements. The target home and the design home will have the same number of stories, condition, floor, area, orientation, climate zone, and fuel mix. So for instance, if the design home has a gas water heater, it's compared against a gas water heater in the target home. One characteristic that may differ slightly is the fenestration area, which is capped at 15% of total conditioned floor area for the target home, in cases where the design home has this much glazing area or more.
For this example, we're just going to look at how three different variables can be traded off to achieve target score. On the left are three target home specs: heat pump efficiency, infiltration, and gas water heater efficiency. The design home in this example, configured to these target specifications, yields an ERI score of 45. On the right is the same home, the design home, with these three specs adjusted slightly. These system specs might be preferable to the builder. The heat pump is less efficient, but the home is tighter and has a more efficient gas water heater with the 0.99 UEF. And the ERI score for this home is 43, less than the target 45, meaning that it passes the ZERH efficiency requirements.
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Now partners will sometimes run into situations when the design home, which seems to be very energy efficient, is still not achieving the ZERH ERI target. And this slide provides a few strategies to address this challenge. So first, make sure that the team is aiming for the right target, which is the ZERH target ERI score for the ZERH Single Family Version 2 program. This score is automatically generated by ERI software that DOE has reviewed and approved, which is then used by HCOs for ZERH and their raters for ZERH certifications. Using a static ERI target, for example, trying to make all the designs achieve an ERI 45 or lower, is not a useful strategy for ZERH compliance because the ZERH ERI target varies with different home designs.
The second strategy is to compare the design home specifications to the target home specifications, which are found in Exhibit 2 in the Single Family Version 2 national program requirements. The design home does not have to match each of these specs for the target home, but comparing specs can indicate where the design home might be losing some ERI points relative to the ZERH ERI target home. For example, the target home for ZERH Single Family Version 2 assumes the use of a high-efficiency electric heat pump water heater with the UEF of 2.57. So if the design home is using an electric resistance water heater with the UEF of just 0.95, this is going to cause the design home to lose several ERI points in comparison to the target home.
And the third strategy here is to adjust different specifications to be more efficient based on builder preference, pricing, design integration, and other factors, and then gauge the impacts on the design home’s ERI. So for example, if the building team is proficient at air-sealing of the shell, consider reducing the infiltration value in the design home. Or perhaps the builder can easily specify a high-performance HRV system with minor cost impact. So this could be another spec to adjust. By going through the process of modeling different what-if scenarios, the builder and rater can optimize the approach to attaining the ZERH ERI target needed for certification.
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So we've now covered the main program components for what you're building needs to do to earn certification. So now we'll cover what builders, raters, and other partners need to do to ensure their home is certified, including the program certification process and oversight requirements.
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This slide shows the general certification process that applies to ZERH Version 2 Single Family. During the design phase, the design team uses the ZERH program requirements to guide the design of a home. During modeling and consultation, a rater models the home using energy simulation software, which has been reviewed and approved by DOE for how it implements ZERH compliance to ensure that the design will meet the required energy-efficiency level based on the design and specifications. DOE communicates with the HCOs for ZERH to let them know which software programs may be used. Next comes construction. The builder constructs the home to the agreed design, deviating as little as possible. The rater works alongside the builder to ensure that the home under construction matches the design and the energy model. In the rating phase, the rater performs site testing and inspections, ensuring that the as-built home matches the design and qualifies for certification. This verification work will also cover the ENERGY STAR and Indoor airPLUS certifications for the home and occurs both during and after construction. And then finally, a DOE-recognized Home Certification Organization for ZERH, or HCO for ZERH, overseas the certification documents and approves the home for certification. This group also reports certification information to DOE.
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So to review everything we've covered in this training, we'll briefly look at a few of the program documents that are available to partners on the ZERH website.
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The four documents presented here are all available on the ZERH Program Requirements web page and describe all the details of the program that we've been covering in this training. The national program requirements cover the certification process, the mandatory requirements, and the ERI target home. There are lots of details and exceptions in these endnotes as well, so if you have a specific question about a requirement or how it should be implemented, that's a great place to start. Then the national rater checklist is used by raters to ensure that all the mandatory requirements are present in a home. This document is a really good planning tool for builders because it outlines exactly what they're going to be compared against when their home is reviewed for certification at the end of the project. The PV checklist is similar to the national rater checklist. It describes everything the rater will check for, but this is for relating to the PV readiness mandatory requirements. And then finally, the policy record is used alongside these three documents. It's published periodically and adds clarifications and changes to program documents in response to partner questions. The amended program requirements can be used as soon as they are published in the policy record, but are not required for use until they're released as part of an official revision.
Devin Neil:
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That sums up the Zero Energy Ready Home program Single Family Version 2 training. For more information, please visit the website to view program documents, frequently asked questions, technical resources, and more. You can also reach out to the ZERH team at [email protected]. We're happy to answer any technical questions regarding the Zero Energy Ready Home program. Thanks for tuning in.