Residential Building Energy Codes – IECC 2010 and Beyond (text version)
Below is the text version of the Webinar titled "Residential Building Energy Codes - IECC 2012 and Beyond," originally presented on February 22, 2011. In addition to this text version of the audio, you can the presentation slides and a recording of the Webinar (WMV 19.4 MB).
Welcome. And I'd like to thank you all for holding and inform you that your lines are in a listen only during today's conference until the question and answer session. At that time, to ask a question you'll press star one on your touchtone phone. Today's call is being recorded. If we have any objections, you may disconnect at this time. I'd now like to turn it to Gail Werren. Ma'am, you may begin.
Thank you, Ed. My name is Gail Werren, and I'd like to welcome you to today's webinar titled Residential Building Energy Codes – IECC 2012 and Beyond. This seminar is presented by the Building Technologies program at the US Department of Energy. We're excited to have with us today a specialist in residential building energy codes who assisted in the development of the 2012 international energy conservation code. He will discuss the future of energy codes and DOE's role in the development of the 2012 edition of the IECC.
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And now, I'll go ahead and introduce our speaker, Todd Taylor. Mr. Taylor is a senior research engineer at the Pacific Northwest National Laboratory. With more than 25 years experience developing and analyzing building energy codes, he is currently manager of residential R&D in DOE's building energy codes program at PNNL. Rose Bartlett, also of PNNL, will be on hand to field questions during the Q&A session. And with that, I'll turn the presentation over to Todd.
Thank you, Gail. As you can see on your screen, I've titled this, DOE's Involvement in Residential Energy Codes. What we're going to cover today is just a brief look at the world of energy code development and how DOE has to participate in that. A look at recent changes to the code that DOE has been involved with and then a little bit more detailed look at some significant changes in the latest revision of the International Energy Conservation Code, IECC. And then we'll talk a little bit, kind of the pie in the sky stuff about where DOE would like to see codes go in the future.
Just as a matter of context, down through the ages, beginning about in the 1980s, late 70s really, minimum codes really were what you'd call minimum. They really did describe what you would look at and say that's the worst house allowed by law. DOE has been involved for a number of years in pushing to get the codes upgraded. But in the past we really did feel elated when we could win 1 or 2 or 3 percent improvement in a code development cycle.
DOE's most significant involvement or heaviest involvement in the codes began in the early 2000s. And probably the first evidence of that was the major change to the 2006 IECC, which began with the '04 supplement before that. Where DOE essentially put in a proposal to complete rewrite the code. Now the emphasis of that change was all on the format of the code. Trying to make it more enforceable, easier to comply with and so forth. Not on stringency. But it did represent DOE's first really major impact on what we call the I codes. The IECC and related codes.
More recently with the 2009 code, which is the current code for at least another almost year, until now, the world has really changed. And this was not all as a result of DOE's actions, but I suppose partly from it. And DOE is now working from two goals that it has set for itself. And those goals being 30 percent improvement in the 2012 IECC. This is relative to 2006. And 50 percent improvement in the 2015 IECC. And obviously when you compare those two numbers to the 1 percent and the 3 percent you see up at the top, that's a major difference in what DOE hopes to be able to accomplish in the IECC.
Just a quick look at the things that are going on at DOE. As I've already mentioned, there are two major code development goals. But there's also one major code implementation goal. I won't talk about that today, but it is important to put things in context. There is the two goals we've already talked about for development. And on the implementation side as a result of Congressional action recently, DOE is trying to assist the states in achieving and documenting 90 percent compliance with the 2009 IECC demonstrated by the year 2017. Now obviously other things will be going on in that time. The code will be advancing. But if you've ever looked at the problem of code enforcement and code compliance, 90 percent compliance is a very big number compared to the way the world has been. So to summarize the context, I guess, things are getting much more serious in the energy codes world than they have been in past years.
Let's look at what has changed around DOE. Three primary differences compared to the previous decades I guess. First is public interest. The general awareness of environmental issues that has advanced through the years has made it very different when you're arguing your case before the International Code Council or the ICC. You basically, you get a lot more support than you used to because the public is much more interested in energy efficiency and anything environmental.
Along with that, of course, political will has increased. We're seeing new laws coming out of Congress that either direct DOE to do things or authorize DOE to do things that they couldn't do in the past or weren't directed to do in the past. And then finally, DOE has seen its pull at the ICC go way up. And that's kind of a culmination or a combination of the two things before it. DOE, as we'll talk about later, doesn't have any special authority in developing the IECC. They're merely a participant like everyone else. But they do tend to have a lot of influence now that they didn't have in years past.
Some notable impacts that have come out of those changes. Obviously, more efficiency is making it into the codes. And I'll talk about that with numbers in a moment. But going along with that, the increased efficiency all tends to put more detail, more complexity into the code. And that is getting pushed into the world of code officials who in the past haven't really had the time and often the expertise to deal with even the simpler older codes. And likewise for the builders, things are getting a little bit more complex. It's harder to find ways to comply with the codes. So there's more need for expertise and analysis tools in the codes process, in the building design process.
And we're also seeing that there's less distinction between the energy code itself and the beyond code programs that many of us are familiar with. Energy Star and that sort of thing.
Speaking of those other things, DOE has its fingers in a lot of pies. Some other things that are not directly codes related but somewhat related, DOE has been involved with helping NAHB develop its own green building standards which have now become the ICC's green building codes and standards. ICC 700, if you're familiar with those documents. DOE's currently involved in developing manufactured housing energy standards as a result of legislation in 2007. There are various appliance standard rule makings that are in process, in progress, that DOE is primarily responsible for. And then you've got all the other programs, the Energy Star, Building America, Builders Challenge and so forth that DOE continues to be involved with, both in their development and their promotion to builders.
All of these provide valuable inputs to DOE in its work in the code development process. But those inputs, the experience of those programs cannot be transferred directly into the codes process. And I'll talk more about that as we go.
DOE's approach to advancing the efficiency of residential energy codes is really informal. If you're familiar with the other things that DOE does, it often has formal requirements that it must go through, formal steps, formal notices that go into the federal register and that sort of thing. None of that applies here, because this is not DOE's process. This process belongs to the International Code Council, the ICC. And DOE's merely a participant in it. It's influence, not authority.
If you're familiar with the rule making process that DOE goes through, for example on appliance standards, I would say it's categorically impossible for DOE to use that sort of a process. Because the International Energy Conservation Code moves too fast. The review requirements, the stages that are required of DOE to do a rule making would basically keep it out of the process and hinder it from participating in a full and effective way. So it's a different world. And that informal world involves engaging all the same stakeholders that would be participating through the federal register, notices or whatever if the DOE were doing a rule making. But it's informal. DOE holds occasional meetings. Generally in the past those have been attended by 60 to 70 people. We maintain an email list for DOE. Many of those names come from meeting attendees, from historical contacts at DOE. Anyone who requests can get on it. But it is informal. You won't find the notice coming out in the Federal Register.
DOE basically tries to cooperate with others who are developing their own related proposals. DOE seeks advice from industry, from all sides of the issues. DOE has procedures in place to review what others are producing, if they want DOE to do so and give advice and so forth. So it's all very informal. But it's a very substantial process that DOE's involved in. Involves a lot of people.
Now I noticed as the survey came by at the beginning that there's probably more energy researchers online today than anything else. And probably the number one question that I get about the energy codes process, especially when people learn of the very aggressive 30 percent and 50 percent improvement goals of DOE's, is why doesn't DOE simply use the Beyond Code Program experiences to design a new residential energy code?
For example, why if DOE has a 30 percent improvement goal, why not simply establish the code to be a home energy rating system, HERS rating, of 70? Well, there's several reasons that that won't work. And I'll go through just a few of the important ones here.
First of all, there's this little law on the books that's been there since 1987. We call it NAECA, the National Appliance Energy Conservation Act. And it basically directs DOE to develop efficiency standards, efficiency requirements for appliances of various sorts. Including residential sized HVAC equipment. And those standards, which regulate at the level of the manufacturer or the importer, are preemptive over the state and local building codes. Which means that states and localities are not permitted to require equipment efficiencies that are beyond those NAECA minimums we call them.
As a result of that law, there are a lot of things that that implies. But one of them in the last code cycle, the previous to the 2012, the 2009 IECC cycle, there was a proposal that came forward to prohibit the trade off of efficient requirements between envelope and equipment. And that's a fairly major change that was put in there because of the NAECA law. What you have as a result is scope mismatches. The I codes we call them, the IECC, because it's going to be adopted by states and localities in order to be used, is not allowed to establish minimum HVAC efficiencies. Those can only be established by the federal rule makings. Whereas the voluntary programs are free to set those. And also for other appliances. But the big point is the HVAC efficiencies. And because of that experiences drawn directly from the Beyond Code programs would often result in a code that literally is not legal for a state to put forward.
Another point related. Because of the NAECA issue, because HVAC equipment and other appliances are not on the table, DOE's goals, the 30 percent and 50 percent goals, are defined differently from the way voluntary programs tend to define their percentage improvements. DOE's goals relate only to the end uses that are regulated by the IECC. They can't impact the others. So we're looking at a smaller piece of the pie than, for example, a whole building number that you might find, for example, with a home energy rating system.
Because of NAECA, DOE's goals simply don't count the savings that are going to be coming from high efficiency HVAC equipment. Because the code can't influence those. And as a result of that, to achieve its goal, 30 percent or 50 percent depending on the year, DOE has to get all of that using only envelope lighting and distribution systems. And if you're familiar at all with the amount of improvement that's available in HVAC efficiencies, it makes a pretty big difference. DOE's goal can be substantially more difficult. Because , for example, home energy rating score of 70, which normally would imply about 30 percent improvement over the baseline, doesn't necessarily match a 30 percent improvement in DOE's goal. Because you can have a score 70 that has high efficiency equipment in trade for some parts of the envelope going down. And you can literally have a HERS 70 score in a home that doesn't comply with the code. We'll talk more about that issue as we go on. But you're beginning to see why a straightforward application of what everyone has learned through the years in the Beyond Code programs doesn't necessarily fit in the context of a mandatory building code.
Okay. A little bit change of direction here. Let's talk about some of the things that have happened in the code recently. And I'll talk very briefly about the 2009 IECC, which is the current code on the books. And then we'll spend a little bit more time on the more recent 2012 code, which is due to be published shortly.
In 2009 there were several major changes to the code that had never been there before. First of all, lighting was added to the scope. In the past it had never really been there at all for most residences. But there was a new provisions put in in 2009 that required at least 50 percent of the lamps that the builder leaves in the building after construction to be high efficacy. And there is a definition of that in the code. Basically incandescents can't meet it. Whereas compact fluorescents and so forth can. Notice that it's 50 percent of the lamps, not fixtures. There was a lot of debate over that. But that's the way it went into the code.
Second, and this is probably the most significant change that has ever happened and the most significant individual change that's ever happened to the International Energy Conservation Code, is there was added to the code a mandatory duct test requirement. Now in the past the code has always said you're supposed to seal your ducts, but there was never any way to quantify that or verify it. And so there was a fairly major change to require that to be verified by testing.
And I've already mentioned that the trade off of efficiency measures between equipment and envelope was prohibited as of the 2009 IECC. So that's a major change in, especially in a lot of parts of the country where that trade off was relied on in order to get certain parts of the code that were unpalatable in the local climate, local builder climate to be avoided I guess. They can't do that anymore. You can't trade away your 2 by 6 walls and go back to 2 by 4's the way you used to simply by putting in a better furnace. That was a pretty big change.
Depending on how you do your analysis you'll find somewhere between 12 and 15 percent improvement of the 2006 IECC. Two thousand six being the baseline of DOE's goals.
Moving on, I have this big because this is where we're going to spend most of our time discussing changes to the code. What has happened in the 2012 IECC, what's it looking like? To begin with, let's kind of look at an overview. DOE believes that what came out of the process, the process is now, for the most part, complete, is improved by 30 percent or slightly more maybe than the 2006 IECC. So if everything holds, DOE believes it has met its goal of influencing the IECC to improve by 30 percent in 2012.
This is not really a change that happened to the IECC, but it is a change that happened to the IRC, the International Residential Code. In the past the IRC has always had a separate energy chapter that had its own energy efficiency requirements that weren't necessarily coordinated with the IECC's energy requirements. That's been a problem from DOE's viewpoint for quite some time, because it introduces an ambiguity out there for any jurisdiction that adopts both the IECC and the IRC.
As of 2012, the IRC has eliminated its chapter in favor of a reference to the IECC. That's, like I said, that's a pretty big deal if you know what that means.
I'll just point out that the 2012 retains the prohibition on envelope and equipment tradeoffs. That will be important as we go. It is scheduled to be published by the ICC in April 2011. However, I will point out that it is currently going through a process of appeal at the ICC. I can't give you any more information on that. I do believe they're having a hearing in March. But no idea whether or how that will influence the publication date or anything else on that code.
Okay. The code does contain a few major changes and many, many minor changes. I will not be going into the many minor changes. I will just focus on the ones that make substantial energy differences and on the ones that I think most people would be interested in even if they are slightly lesser in impact.
Let's start with the major changes. First of all, and this is one of the bigger ones. There has been added to the code a mandatory whole house pressure test. You must pressure test the home before you turn it over to the occupant. And the required leakage rates are fairly aggressive by most accounts. In the southern part of the country, zones one and two, not more than five air changes per hour when tested at 50 Pascals. In the central and northern parts of the country, less than or equal to three air changes at 50 Pascals. Depending on where you work, those are either extremely aggressive or very aggressive.
Oh, I should note here that if you downloaded your presentation from the website there was an error in this slid in the presentation out there on the website. You'll see zones one through three as five air changes and four through eight as three. Be sure you mark those out and note that it's one and two at five and three through eight at three.
Second major change, domestic hot water piping. This, according to the studies we've seen and the experts we've contacted, has the potential for saving about 10 percent of the hot water load. What the code now requires is that you insulate all hot water piping to R3, unless you can show that the run between the tank and the fixture is short and skinny enough. And what I mean by that, it's intended to limit the amount of stranded hot water volume that will sit in the pipes and cool and off and be wasted. So the code provision is intended to encourage a hot water tank that's centrally located within the home and a distribution system that's laid out in a manifold arrangement rather than a trunk and branch arrangement. Because that will significantly limit the amount of stranded hot water. So the preference is that builders will learn to do that. The alternative, if you don't want to do that is you have to insulate all of your pipes.
The duct leakage rates. The duct test was added back in the '09 version, but the requirements of that test have been tightened up a bit in 2012. First of all, an option to measure leakage to outdoors was eliminated. In the '09 you had your choice. You could either measure leakage to outdoors or total leakage. And there were different requirements for those two. You could also measure either after HVAC rough in or later after completion of construction. And that was all put in there and DOE's proposal in order to give builders a lot of flexibility in how they comply with this. But DOE heard from the builders afterward that there was so much flexibility there that it made things confusing. So in 2012 as the leakage rates were improved some of the options were taken out. It was believed that the builders would prefer to retain the option of testing either at rough in or after construction. And in order to retain that, leakage to outdoors doesn't really make sense. At least not at the rough in stage.
So you can see the improvements. Total leakage was reduced from 12 CFM per 100 square feet of conditioned floor area if you test after construction or from 6 down to 4 if you test at rough in.
And there were also various improvements in R values and U factors and coefficients and that sort of thing. Which we'll talk about next.
Let's begin with ceilings. As you can see in zones two and three, which are the south except for the Gulf Coast and the next zone just above that, increased from 30 to 38. Zones four and five increased from 38 to 49. Pretty straightforward.
Walls. This is a fairly major impact. Not necessarily so much in terms of the percentage reduction in energy consumption, although there are a few percentage points here. But in terms of impact on builders this is a pretty major one. Zones three and four, as you can see, the requirement for wood frame walls went from R13 to either R20 or R13 plus and R5 insulating sheeting. Zone six you can see went from either an R20 or an R13 plus 5 up to R20 or 13 plus 10. So the insulating sheeting went up there. And then in zones seven and eight, which are the far, far north, we've gone from an R21 requirement possibly down to a 20 plus 5 or down to a 13 even if you add an R10 sheeting to go with that.
Well, before I talk about the implications of those, look also over on the mass wall R values. Mass walls refer to concrete walls, concrete block or log walls. Anything that has enough thermal mass to influence significantly the heat transfer through them, especially in the summer months. And what you'll see in zones three and four, that R5/8 that refers – the R5 refers to requirements when the mass is on the inside of the insulation. In other words, when the mass is in contact with the room air or integral with the insulation. The eight refers to the requirement if more than half of the mass is on the outside of the insulation. So those numbers, 5 and 8, got bumped to 8 and 13. And then similar things happened you see down in zone six.
What are some of the implications of this? First of all, you'll hear people say that 2 by 6 construction is now required in some zones. That's not really true. It's not required. The prescriptive level would, if you build directly to the prescriptive level you will need to do 2 by 6's or put sheeting on, insulating sheeting. But you're always able to do tradeoffs if you don't like that. The issue comes into play because, as we've already mentioned, envelope equipment tradeoffs are prohibited. And because the other portions of the envelope have gotten much more efficient on their own, finding enough envelope only trade off can be hard. Depending on the design of your home and the zone you're in, it can be extremely difficult to find a way to build a house with 2 by 4 walls that does not require the use of insulating sheeting.
And that brings us to the next point. Log walls are difficult to comply at all without moving to a larger diameter than is common in many places or using some kind of a furred in approach in putting insulation inside a flat wall on the logs. And that's a problem that many are dealing with right now. It's something you should take note of.
I've mentioned insulating sheeting in talking about the 2 by 6 construction. You will also hear the comment from people that insulating sheeting is now required in some zones in the far north. The same comments apply. It's not formally required. You are free to trade away. But the envelope options are still limited. The equipment options are still prohibited. And in addition to that, some of the bracing options are more limited than they used to be because of some recent changes in the International Residential Code. The structural part of that code.
So there are some things to take note of. It will take some thought to learn how to build a home to this code. And it will take some thought for code officials to learn to enforce it correctly.
Moving on, basement walls and crawl space walls. The foundations. A couple of changes affecting the northern parts of the county with some increases in insulation. For example, if you look at the basement wall column, the R10/13, the 10 refers to the requirement if you're using exterior insulation. Continuous insulation along the entire wall. The 13 would refer to cavity insulation that's in a furred in wall on the inside. Those numbers went up from 10 and 13 to 15 and 19. And then similar changes if you have what we call a conditioned crawl space where you've insulated the crawl space wall.
Moving on to fenestration. In the IECC fenestration - well, fenestration itself, the word refers to both glazing and doors. And in the IECC the requirements for those two elements are the same. All fenestration has the same U factor requirements. And you can see the changes that have taken place here. I will point out in zone one, the 1.2 U factor going down, improving to 0.5. You'll find that change only in the U factor table of the code. There is also an R value table in the code. And the 1.2 was changed to a no requirement there. That's kind of a nuance. I only mention it so you won't be confused if you see it. But the U factor table is the one that's going to be used for any UA type trade off calculations and that sort of thing. And so that's where the U factor's important. But it has not changed the base requirement for U factor in that zone, because you can always use the R value table. And it will allow basically a single pane window.
And you can see the other changes as it goes through the various zone levels. Note that skylights are different in every case, because it is much harder to achieve a low U factor in skylights. So those allowances are a little bit higher. And it's just important to note that they are different.
Looking over at the solar heat gain column. You'll see in the south, the first three climate zones, FHGC has gone down from .3 to .25. Except skylights. In skylights you can still use .3. Something that is new in this cycle, climate zone four, except for the marine portion of that zone over on the West Coast, now has an FHGC requirement of .4 or less. Whereas in the past it's always been no requirement.
Before I move into the future directions, I just want to remind everyone, if you have questions you need to be asking them now. Don't wait till the end. Click the little button at the top and type in your question after hitting the ask button. So that those are in the system and ready for us when we get to that part of the presentation.
Moving on from the current state of the codes, let's look at what DOE has planned in the future. And this is, I mentioned earlier, I think I called it pie in the sky. When I say that I don't want to lead you to believe that DOE's not serious about the goal. DOE is very serious about achieving 50 percent improvement in the new code in 2015. But it's not clear how that's going to happen. There's a lot that has be to be learned between now and then. So let's talk about what that'll take.
DOE does plan to develop a specification that's 50 percent better. And it plans to find one that will work without running afoul with NAECO. Without having to require higher efficiency equipment. But we know that's not going to be easy. And in order to do that DOE is planning to evaluate some alternative ways to specify, to format the code. And we'll talk about that as we go here.
Question. What does it take to improve the code by 50 percent over the 2006 IECC? And that's a question that we at PNNL will be trying to answer, that DOE will be trying to answer. And we certainly appreciate any inputs anyone has on that topic.
So the first question we ask is what else can be improved in the code? What can we do? Good questions. There are a few areas that you can think about that the code doesn't currently regulate where it might be changed to include some specs. Orientation restrictions perhaps. There are none of those, at least not in the prescriptive code. Requirements that are sensitive to house size. Maybe there's some optional things in the code right now that have only been used in trade off scenarios before that might be made mandatory. Maybe there are some appliances that can be pushed into the scope of the code if those appliances are not covered by the NAECA laws. Maybe there's some quality control things that are not in there. Refrigerant charging. Duct balancing. Or air balancing of the duct system. Thermostat placement. What have you.
Many have suggested that there could be a direct requirement of certain levels of renewable features in the home, whether it's photovoltaics on the roof or solar water heating or something like that.
One thing that we're trying to figure out is how we can redesign the code so that it encourages the use of energy efficient features that in the past have not really been possible to do within the code. And let me give you just a quick example of what that might be. Many people have often wondered why doesn't the code require some curtains or some shade trees or something to help keep the sun out of homes in the south. Well, there are a lot of reasons for that, but I'll just show you an example here. I love this. This is up in Portland, Oregon. This is I believe a city government building or maybe it's a state government, I'm not sure, building. That was being remodeled, is being remodeled. And the plan is to put these nice green trellises all along the west face of the building to keep the sun out. I don't know how well that's going to work. I don't know how you're going to keep it watered. I don't know who's going to go up there and trim it. But it seems like a good idea.
But the question is, could you ever get that into a code? It would be hard. Trellises – deciduous tree is a good example of the issue that I'm talking about. I grew up in the South. And I know how important it is to have a nice big deciduous tree on the south face or the west face of your home. They make for excellent sun blocks in the summer. They drop their leaves off so they let the sun through in the winter. They're very inexpensive to install and their performance improves with time as they get bigger and bushier. They can increase the value of the home. They don't spew any carbon when you make them. Just about everything you can say about that tree is good except you can't spec it in the code. You can't predict its performance. And once in a while, as I say, George Washington will move into the house and cut down your cherry tree.
So is there any way in designing a new format for the code that you can make the code encourage that sort of thing even if you can't require it directly? That's one of the questions we'll be trying to answer for DOE. And we would certainly appreciate your input.
Back to the question I asked earlier. Why doesn't DOE simply apply its Beyond Code program experience to the design of these codes? One more point. Calculating the impact of almost any measure that was not previously regulated is complicated. And this matters more to those of us who do research and development on codes than to others. But it turns out to be a somewhat interesting problem.
Cutting off the tail of a distribution is very different from how code improvements normally work. When you think of a code improvement you're usually thinking about making an R value higher or a U factor lower. But when you expand the scope of the code, when you begin to regulate something that the code didn't regulate in the past, it's a different matter.
Just to give you an example, I'll use air leakage as an example. Assuming that air leakage was not regulated in the past but you're considering a provision that would do so. There's a distribution of homes out there in terms of how leaky they are. Some builders build them tighter than others even without any requirements. So you can imagine a distribution, I don't know what it looks like. I've made this one normally shaped. And there's some average leakage rate of homes out there in the wild represented by that little blue line. A number of homes to the left that have lower leakage. Those are the better homes. And homes to the right are the worst homes.
Now suppose that someone got a change into the code that added a requirement to the code that wasn't there before. And that requirement was worse than the average. So for example, if the average pre-code leakage rate was say seven air changes per hour and this hypothetical code requirement came in at eight air changes per hour. If you simply compare those two like you would normally compare the change in an existing provision, you would conclude that the code was making buildings less efficient.
That's actually not what's happening at all. Actually what the code is doing is screening out and eliminating all of those homes that are worse than eight and not changing those that would have been better than eight. So it is having a substantial improvement. But it's an improvement that you can't calculate by comparing two buildings, for example the way a normal performance path is done or the way a home energy rating system is done and that sort of thing.
So that's just one more little nuance as to why some of the experience, much of the experience that DOE has in Beyond Code programs is not really easy to carry forward in tracking its progress toward its 30 and 50 percent goals.
It's not clear to us that achieving 50 percent improvement can happen with a purely prescriptive or a primarily prescriptive code. You can imagine continuing to increase some of the R values and improve the U factors, but at some point you throw your hands up and you realize that diminishing returns are eating you alive. And you just can't do that. So we believe in all probability it will be necessary to find a new way to format the code. A new way to specify the code that's not so purely prescriptive.
And several of the options include what some have called performance plus. I like to call it prescriptive plus. It's basically where you take a code that's formatted much like the current IECC, so that it has a prescriptive baseline and a performance path where you do a comparison of your home against that baseline. And rather than being held to equivalence when you do those two home comparisons, your proposed home has to be some percentage better than the baseline home. And that puts the onus on the builder and on the builder's consultants perhaps to figure out how to build a home that's X percent better than the old code.
Another possible approach is a simple annual performance budget. BTUs per square foot. One number is the whole code. Have a ball. Build anything you want. Some have said perhaps it should just simply be an annual performance budget in BTUs rather than BTUs per square foot. In other words, let the size of the home matter. Make it easier to comply with a small home. Make it encouraged to build smaller homes. You're already thinking of the pros and cons in your head I know.
Some have suggested that it be an annual carbon budget rather than an energy budget. We have looked at that. We think that introduces to many complexities. And I don't expect DOE to go that way, but it is one possibility. Others have suggested post occupancy evaluation. Also known as outcome based codes. Another thing that DOE has evaluated. I don't expect that to happen. There's a lot of problems with that, especially in the residential world. But it is one approach that really is focused more on compliance and enforcement rather than the design of the code.
Some have suggested that there be a requirement for certain levels of renewable energy features. Regardless of what else might – you know whether you calculate it to be right or not, some have suggested it should be required. That's one possible approach. And then one final one that I'll talk about is adding capacity constraints to the code. And I'll talk about what those mean as we go.
The prescriptive plus, where you do a performance path comparison but your proposed home has to be X percent better than the code home, has some strengths and some weaknesses. Some of the good things about it is it allows the flexibility that you want in a performance path while allowing for some important features to be made basically mandatory in the prescriptive specifications. Its weaknesses, as you can imagine, is requiring the same percentage improvement for every home. It may not be fair, even sensible, may not even be possible depending on your location. Because there are different fractions of heating, cooling and water heating depending on where you live. So one number fits all homes is a hard thing to do.
It requires an infrastructure that's not currently adequate out there. And this is going to be true of nearly everything we do. There's going to have to be some improved infrastructures in the code officials' world and/or the builders' world to be able to accommodate these kinds of calculations that would go along with a new format. It does complicate the enforcement as you go.
One of the things that's true of almost every alternative format you're going to look at is that the incentives to the builder tend to be inverted. They tend to go the wrong way. When you're regulating a calculation about a building, the focus is all on the calculation. The focus is for the builder is getting the home through this process and declared efficient. The focus is on simulation, not on the building. And that sort of thing. It has a tendency to push builders toward working for things other than just making the building right. Pleasing the code official rather than pleasing the occupant. And that's, like I said, it's a problem that's almost universal. There is one possible format that might deal with that.
Moving on. Simple annual performance budgets. Strengths. Maximum design flexibility. In theory it can accommodate anything. The disadvantages, it may favor some larger homes over smaller ones unless you introduce a lot of complexity in how the number is determined. And then it shares many of the difficulties that you'll see or that we talked about in the previous one. Lot of reasons why it gets more complicated. But it avoids having to specify everything down to the level where you're wishing that you could specify equipment efficiency, for example.
Annual performance budget. Do I have this one repeated? Did I – yes. I apologize for that.
Carbon budgets. As I said, I don't expect DOE to do that. You'll find every similar strengths and weaknesses. New controversies that it would bring in where not all BTUs are equal. Heating and cooling are worth different amounts. Heating and cooling are worth different amounts in different parts of the country. Do you accommodate green power and carbon credits and so forth? It could get really, really complicated to try to implement the code as a carbon budget. So that's probably some years down the road. But I do mention it here because DOE has looked at it.
Mandatory renewables. Can we simply require a certain level of PV or solar water heat or whatever? The big advantage of that is it would promote market transformation for those things. It would help bring down the cost of photovoltaics, for example, for everyone. And build on itself in that way. Its disadvantages, of course, is that it may not make economic sense everywhere in a certain and particular zone. And it's only part of the solution. You can only get so much out of it. There's only so much roof area on your home to put PV on and that sort of thing. So it's an idea, but it has its issues.
The final format that is possible is capacity constraints. If you think about that, I don't believe in recent decades any code out there has tried to constrain capacities in buildings. So let's talk about what they are. First of all, let me point out that most code provisions today, although they're designed to limit the amount of energy consumed in a house, they don't directly regulate energy. They regulate some surrogate for energy. They change an R value. They change a calculated simulation result. Rather than directly regulating energy.
So the question is, is there something else that we can do to get at the energy in an indirectly way? Direct energy constraints are very difficult to enforce. As I've already mentioned the post occupancy metering is one way. But that brings in all of the questions about what kind of enforcement infrastructure you would have to build to do that.
So what can we do? One proposed solution is perhaps regulating capacity will indirectly allow us to influence energy. And as we'll see, it has some peculiar advantages that none of the other format ideas really has. The simple example of a capacity constraint, imagine an all electric home and you design a new code that has just what you see on the screen. Your electric panel is not allowed to be more than whatever it is. Seventy amps. We'll give you 70 amps for that house. Build it any way you want. Have a ball. It's up to you. You get 70 amps.
What does that do? Well, it has a lot of advantages. It's 100 percent an easily enforceable by a very unsophisticated code official. You don't have to do a lot of training. Inspections literally take 15 seconds. Because the only thing the code says is check the electric panel. But it puts a huge burden on the builder to figure out how to design and build a home that will actually work within that capacity constraint.
The good side of that is the builder's invest, these incentives are no longer inverted. The builder's interest is now shifted completely toward making a house that really will work. All of a sudden everything matters directly to the builder. It matters what the orientation of the home is. It matters how well the insulation job is installed and so on and so forth. But, of course, it does put a huge burden on the builder that has not been there in the past. The house really has to work or it won't work.
Of course the reality is you could never get by with a code that simple. The reality is you'll need to limit several capacities, probably at least the furnace and the air conditioner capacity. And maybe there's some others out there. And of course we don't know for sure how it will work. It might discourage certain kinds of control options because those don't necessarily help you fit within the budgeted capacity constraints. And the reality, again, is probably that capacity constraints would have to be paired with more traditional prescriptive kinds of requirements in order to achieve the kind of energy savings desired. We have honestly no idea whether this will work, but it's one of the things that DOE is going to be looking at in the coming months.
I'll skip over the strengths and weaknesses here because I think I've already talked about them. And whoops. I apologize for that.
To summarize. Things are getting very serious. If DOE is successful with its 50 percent goal, the IECC itself will be as good as or better than most of the Beyond Code programs that folks are using today. Calculating the impacts of those things in a way that's comparable with those Beyond Code programs is difficult. And everyone should be aware of that so that you're not confused by a home energy rating system score on a house that the code official deems noncompliant.
There will be a requirement that we make some creative changes to the code format and/or possibly the enforcement infrastructures. And possibly the world of the builder himself. As we pointed out there in your last bullet. It's not going to be easy. But it's certainly going to be interesting.
And with that I will turn this back over to Gail and we will prepare to answer some questions if we have time. As we have time. Gail?
Thank you, Todd. As I mentioned, we have some additional polling questions before the Q&A session starts. If you do have questions for the Q&A, please submit them through the Q&A link at the top of the bar on your screen and the team will answer as many as possible after the polling question.
The first polling question is up now asking what were you hoping to learn from today's webinar? Thank you.
And the final polling question asks how satisfied you were with today's webinar? Thank you.
Now we'll get into the Q&As. As I mentioned, we ask everyone to submit their questions online. Todd and Rose will address as many questions as time allows. Rose, would you like to start?
Sure, Gail. Thanks very much. I have a few questions here that I'll start off with as Todd is reviewing all of the questions that have come in. And thanks very much to everybody for submitting those. One of the questions we received asked how many states have adopted the 2009 IECC as the basis for their energy codes. So I went out to the Building Energy Codes program website at www.energycodes.gov and took a look at the status of state codes. So whomever asked this question and anyone else who's interested can go to energycodes.gov to get further details. By my rough count it looks like as of right now there are about 13 states that have adopted the 2009 IECC as the basis for their energy code or as their energy code itself. So hopefully that answers that question.
Another question, you said that because of NAECA that 2009 IECC and 2012 will prohibit envelope equipment tradeoffs. Why? Well, why is really a question that you can't answer too definitively in the ICC process. But I thought I would just share with you some of the arguments that were given at the hearings to disallow that envelope equipment trade off.
First off, NAECA, as Todd as mentioning, prohibits the states and, therefore, the IECC, from regulating the equipment efficiency. It also was observed by some folks that standard practice in a lot of places already substantially exceeds NAECA minimum efficiencies. That is equipment minimums haven't kept up with the rest of the world. And therefore, to avoid a free rider bypass, if you want to call it that, where envelope efficiencies could be traded away for high efficiency equipment that likely would have been used anyway. Most people didn't feel that it was appropriate for the IECC to give credit for major component that it can't regulate. And it also was felt that any energy that's saved by the equipment ___ ___ last maybe 15 to 20 years. But only until the equipment wears out. And envelope efficiency lasts much longer and up to the life of the house, for example.
Another question that came in, what percentage of energy is expended for buildings? The Energy Information Administration says that nearly 40 percent of the nation's total primary energy is used in the nation's commercial and residential building. So that's a pretty high percentage.
Todd, do you have a few you want to answer?
Yeah. I'll start through a few of these. First one, someone asked, where did the 30 percent and 50 percent goals come from? And that's a very good question. Not one that I'm sure I can answer completely. The goals were decided upon at DOE as a matter of high level – it was a high level policy decision. I believe they looked at what was going on in the various Beyond Code programs, in some of the efforts that were going on for learning how to build, for example, net zero energy homes and that sort of thing. And out of that came these policy decisions, these policy goals of 30 percent and 50 percent.
Note that they are simply goals because DOE cannot regulate those things. DOE doesn't create the code. DOE can only influence it. So they're numbers to work toward, to track progress toward. And as far as I know, DOE has achieved the first one and will be working hard toward the second one.
Another good question that came in having to do with the new plumbing requirements in the code. The question is, have the sections of the code, the plumbing code, the IPC or the IRC plumbing provisions, been revised to allow smaller diameter piping for example, quarter inch, to go to some of the low flow fixtures? Or do these conflict with the 2012 IECC?
And the answer, to my knowledge those portions of the plumbing code have not been modified. There are some efforts I believe to try to do that. Which will make it easier to comply with the new provisions in the 2012 IECC if those do make it through. But for the time being you're somewhat limited on how to make your pips short and skinny. In other words, you have to work harder to get them short. Because the code will limit how skinny you can make them. And that is a big issue. You can make a very efficient hot water system if you are allowed to go to very small diameter piping when you run out to some of the lower flow fixtures. So very good comment. Very good question.
Some of these questions are not easy. And this is one of them that's not. The question is, will log wall compliance requirements make the log home a construction method of the past? Without adding insulation on the inside for smaller diameter logs.
Very good question. Because as I mentioned in the presentation, the wall requirements have been tightened enough and the other requirements in the home have also been tightened enough that it is very difficult, depending on the design of the home, the size and the shape and the glazing area and so forth. It is very hard to build a home with the smaller diameter logs that are common in most locations. Even considering all the possible trade offs.
So taking it simply as the way the code reads there are places in the country where you will be required to either add insulation, fur it in somehow on the inside. Or go to a larger diameter log. There are some states who are looking at the IECC or I'm sorry, the 2009 IECC and seeing this is an issue in their jurisdictions and they are considering ways to modify the code before they adopt it. And I can't go into detail on those because I don't know them well enough. But I do know that there are some states that are finding that to be a concern. And what will happen going forward I am not sure. But your comments are certainly helpful. If you can formulate your thoughts and send them to DOE that would be very helpful.
Some of these are easy questions. Will these codes apply to residential resale as well? And the answer is generally no. Retrofit, yes. If you are tearing a wall out and rebuilding it, then the code applies. If you're simply reselling an existing home, no, the code does not – you do not have to bring that home up to the new code.
Next question deals with steel frame homes. And I'm not completely sure I understand the question. The question is, what about steal frame homes in the case of multifamily? First of all, I'll point out that what I have been talking about today is what most people generally simply call the residential portion of the code. But in reality it's the low rise residential portion of the code. It doesn't cover all residential – multifamily residential four stories or higher is not covered by the portion of the code that I'm talking about. Three stories and less is covered.
But in the low rise residential there are some tables in the code. I didn't show any of them. For equivalent efficiency numbers for steel studs. So if you are building a building with steel studs there is a provision in the code that is designed to be in an energy context equivalent to the wood frame requirements.
Next question. Would a builder of tract homes be required to do a blower door test on each and every home in a large development? Or just one representative home of each design? This was a question that was debated long and hard in the I code process. As the code is written right now in the 2012, you would be required to ____ door test each and every home. The original proposal that required the ___ door test, which was put in by DOE as well as others, DOE's anyway had a provision in there to allow the code official to implement a sampling procedure much like some of you may be familiar with in the Energy Star process. But that sampling procedure was removed by a public comment that was approved at the second hearing of the ICC this past fall. So what was finally approved does not have a sampling allowance.
I will point out, even if you put a sampling allowance into the code, it's not completely clear how that works at the enforcement level. The way code enforcement generally works, the code official is signing off on an individual home. And not signing off on a subdivision or on a collection of homes. Not promising they don't average they're good. He's promising that that one house is good. So there has been some debate as to whether you can even legally do sampling in a code compliance or code enforcement context. And I guess that's an open question. Because sampling is not in there at this point.
Todd, I have a couple that I'll answer. One is, does the 2012 IECC require mechanical ventilation when air leakage rates are so low? The three air changes per hour at 50 Pascals, I guess for example. I guess the answer is not directly, although a lot of people would suggest that, you know ventilation would be needed at those low leakage rates. But a lot of people believe that ventilation's needed even at the average leakage rates. So that may be true in some parts of the country, depending on the local air ceiling practices. So I guess you could say in one sense the 2012 hasn't directly impacted the needs for mechanical ventilation. But on the other hand, with tighter homes that will result from the code builders are probably pretty well advised to consider ventilation if they don't already do that.
Next question is, how do you see the code changes impacting Beyond Code programs? Will there be coordination between the two? Well, I think as Todd had mentioned, certainly as the minimum code becomes more efficient those Beyond Code programs are having to reconsider their elements. And I usually use the term ratchet them up. So they can continue to be Beyond Code programs. I don't know that there's any formal coordination among those. But I am well aware that there's a lot of discussion going on and many of those beyond code programs now, they all keep track of what the minimum code is doing. And so they're all well aware that their programs will need to be modified to continue to be considered Beyond Code programs. Todd?
Okay. Next question, is there a performance option to override the prescriptive code requirements? And I don't know which code this question is referring to, but the answer is the same for both the 2009 and the 2012 IECC. The answer is, yes, there is a performance option. You can go that route and do a full whole house energy simulation and compare it for your proposed house against the code house. However, as I've continued to emphasize, it is not permitted to take credit for higher efficiency HVAC equipment in that trade off. So it is a much less flexible performance option than many are accustomed to. So I hope that's being made clear.
There was another question about that. If I can find it I'll try to answer it at the same time. But I don't see it at this point. Maybe we've already answered it.
Next question. In general will there be similar changes to chapter 5 of the IECC, which is the commercial building portion of the code? The answer to that is in general, yes. Specifically, no. Chapter 5 is very, very different from chapter 4, which is the residential side. So none of the particulars that I've talked about today apply directly to chapter 5. However, there were changes made to chapter 5 in the 2012 IECC that DOE believes approach 30 percent improvement in commercial buildings. So yes, things are happening in chapter 5. But no, they're not in any way equivalent or identical to what's happening in chapter 4.
Next question. I thought you mentioned R value for fenestration, but I don't see that in the code. Could you direct me to it or did I misunderstand? When I refer to that I'm referring to what most people will call the R value table of the code versus the U factor table of the code. In chapter 4 there is a table 402.1.1 that expresses prescriptive requirements in terms of R values for those portions of the home where that makes sense. It also contains U factor requirements for fenestration.
There is a second table, 402.1.3, that gives essentially the same requirements, but expresses those R values in terms of U factors. And it also has fenestration U factors. The difference between those two is you use the U factor table, the second one, if you're doing any kind of UA trade off. You can use the first one if you simply want a pure prescriptive code without any question about the relative efficiencies of ceiling versus wall and the relative size of ceiling versus wall and that sort of thing. So the R value table actually has some U factors in it. R value table is kind of a colloquial term that people familiar with the code will use.
Next question. Speaking of building envelope and the use of right sized HVAC, spray foam offers the tightest seal and the highest R values, and thus allows for downsizing in the use of 2 by 4 studs. Will this be allowable? And the answer is, yes. Sprayed foams, cellulose, any kind of insulation that will fit within the normal residential construction techniques is allowable and will go toward the U factor requirements. So there's really no distinction at all by the type of the insulation. Unless a particular type of insulation is not able to achieve the required R value in the available cavity.
Next question that came up here. What – I'm sorry. The National Appliance Energy Conservation Act was established in 1988. Actually, I believe it was '87. Someone said that the removal of the options for the mechanical equipment tradeoffs against the building envelope in the 2009 IECC was because of that law. What changed in the law to prohibit options for such tradeoffs? And I believe Rose has already answered that, but I want to clarify it one more time. This is a big point. Nothing changed in the law. There's nothing in the NAECA law that prohibits tradeoffs. The IECC as of 2009 prohibits those tradeoffs because the arguments that were made by proponents of that prohibition carried the day. And Rose has already shared with you those arguments. So that's simply a provision in the 2009 and now the 2012 IECC. Has nothing directly to do with the law. It's just that the existence of the law is what pushed those proponents to propose that prohibition.
There is a similar question that came in, Todd, about asking what's the potential that DOE will address those limitations within NAECA so they don't adversely affect the energy codes. Want to take a guess?
I know it's been discussed at DOE, but that's about all I could say about it. The potential that DOE would address those issues.
Are you talking about in the law or in the code itself?
I think they mean within the law. With NAECA.
Well, of course the law itself is under Congressional prevue. And there has been at least one modification to that law in recent years that allowed DOE to establish two requirements rather than one for a given type of appliance. For example, right now ___ the furnace AFU has to be the same all over the country. There is an allowance in the law now that would permit DOE to establish both a northern value and a southern value, for example. But there are very difficult questions to answer on how you would enforce such a thing. Because NAECA, the law itself, regulates the manufacturer not the builder. And yet it's the builder who's going to ultimately buy the equipment and carry it and install it in a home. The builder or his subcontractors. So enforcement is going to be very difficult of that two zone approach. And this is completely my speculation, but I have my doubts that you will see a two zone system any time soon. I just don't think the enforcement issues are that easy.
As for the code itself, will DOE try to change the prohibition, eliminate the prohibition? I think it's possible in an indirect way that that might happen if DOE is successful or identifies successfully a way to reformat the code to more readily accommodate all kinds of energy features, including equipment efficiency. But that's a completely open question at this point.
There was also a question about fostering compliance, because Todd had mentioned the ARRA legislation has the requirement for states to demonstrate 90 percent compliance with the 2009 IECC on the residential side by the year 2017. And this person asked about education of new officials, continuing education of present officials and then also education of the industry professionals as well. As this could be a potential future webinar topic. And I certainly would agree with that. That's a big goal. That 90 percent compliance, as Todd mentioned. Pacific Northwest National Laboratory has been undertaking a lot of efforts in the past couple of years to help states try to demonstrate 90 percent compliance. And we have a lot of information about the methodology that was developed for that and some of the tools and techniques that have been developed for that on energycodes.gov. Todd?
I'll bring up one more here. Let me choose a good one because we're running out of time. Decisions. The International Green Construction Code, which I'll point out at this point is a commercial code, but it uses a source energy efficiency as a metric within its performance task. Is the Department considering proposing a similar use of source energy efficiency perhaps with different targets, for the 2015 IECC?
The debate here has to do with whether you're balancing things based on source energy or site energy after it's undergone whatever losses occur between the source and delivery to the home. Or perhaps what happens a lot in the IECC, which is energy cost. I believe that most at DOE would say source energy is the preferred metric in terms of being, of regulating the right thing. But it can be very difficult, mostly in terms of debating over what the right source conversion efficiency factors are. It depends on the mix of generation in your locale, for example. What the conversion factor for electricity is, depending on whether you have hydroelectric or coal, for example. So it tends to be a controversial thing.
DOE up to this point has tended to favor and has pushed for the code, for example, the IECC residential chapter, to do its trade offs on a basis of energy costs. Because energy costs tends to and in the local environment, be a fairly good surrogate for the actual conversion efficiencies that are going on. Not perfect, but reasonable. So that's what's been used in the past. It would not surprise me for DOE to push harder for a source energy basis. But I can't answer that directly.
And with that I think we're running out of time. So I will turn it back over to Gail, I believe. And Gail will fill you in on this. That all of these questions will – maybe I shouldn't answer that. Gail, it's all yours.
Okay, thank you, Todd. We'd like to thank our speaker for his time today. We'd also like to thank all of you for participating. Please visit buildings.energy.gov/webinars to download a copy of the slides. Also check this web page for information on future building technologies program webinars. This concludes our presentation.
At this time at the close of this conference you may disconnect and thank you for your attendance.
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