Feedback on the standard adaption: A summary

GWLast year the PHIUS Technical Committee published its draft report on a climate specific passive building standard. It also called for formal public comment. Here, with an update on that process, is PHIUS Senior Scientist Graham Wright.

We got some good feedback on our standard-adaptation work – fourteen folks submitted some fifty pages of formal commentary altogether. Thanks to all who took the time to write out their thoughts. The PHIUS Technical Committee (TC) reviewed all the feedback.

I’ll summarize the process, but first you might remember that our report is also a report to U.S. Department of Energy Building America (BA) program, a proposal for the next-generation Zero Energy Ready program (ZERH). The reviewers for BA sent 134 line-item comments on the draft report. (We’ve been busy responding to those, and we think the final report is much better now!)

Click on the cover graphic to download the final U.S. DOE Building America report at the Building Science Corporation site.

The DOE/BA and the passive house community have the same goals and are, at a broad conceptual level, working on the same thing (otherwise this work would not have been funded.)  At the workaday level though, there are a lot of differences, and also a lot of investment by the two communities in their own approaches – it’s part-and-parcel with the commitment and passion for better building that both communities share.  But when you ask the questions “is there anything passive house can bring to BA/ZERH” and “is there anything BA can bring to passive building,” it turns out the answer is yes.

The TC believes we’ve achieved a fruitful synthesis, a best-of-both-worlds combination. For example, when it comes to designing for high performance, we agree it’s better to set performance targets and do an energy design than to use prescriptive tables (and by the way that design can be somewhat site-specific). But when it comes to field quality assurance, then  a checklist table – like the BA approach — is the right tool for the job.

To put a finer point on it, we at PHIUS hope the final report persuades BA that the ZERH program should be a performance standard, with criteria on both heating/cooling loads and on total source energy, and that those performance targets are predicated on ducts inside, strict air-tightness, and using really good windows for comfort reasons.

Likewise we hope it makes the case to the passive building community that the heating/cooling criteria can be adjusted for economic feasibility / competitiveness in a climate-sensitive way, that the risks to comfort and building durability are low, and that the heating/cooling energy savings are still impressively deep.  Over all the climate locations studied, the proposed criteria represent median reductions in peak heat load of ~77%, annual heating of ~86%, peak cooling of ~69%, and annual cooling of ~46%.  (The baseline is 2009 IECC code.)

So, about those formal comments: Most commenters checked either 12-20 or 20+ years experience. In terms of survey questions we asked, no one liked star-ratings, so pass-fail it is. In going through the feedback the TC found no surprises–most all of the concerns had indeed been fully vetted en route a consensus over the past two+ years.  Here are some of the specific questions we received, along with answers:

Q: Could WP software be modified to make heating/cooling load calculations consistent with ACCA Manual J and ANSI/ASHRAE/ACCA Standard 183?
A: That is possible!  Added to the feature request list.

Q: Could PHIUS consider consolidating QA/QC checklist to be free standing from DOE ZERH and EPA Energy Star (for both residential and commercial projects)?
A: Some progress has been made on this. Stay tuned.

Q: Will the standard help me design smaller passive houses?
A: The short answer is probably yes.  There is no explicit “small house break” but there are three changes that indirectly tend to benefit small detached buildings at least in some climates:  air-tightness criterion by shell area instead of volume, source energy allowance per person instead of per square foot, and higher plug load defaults and detailed internal-gain accounting.

Q: Has there been any progress with PHIUS and NFRC in aligning data to meet PHIUS needs and possibly using NFRC data?
A: Not a lot. But we want to get it done this year. Third quarter.

Q: Please explain why you chose the specific denominators in the formulas. For example, why $ 0.155 electricity? 482 kWh? 1341 HDD65?
A: Those are the best-fit numbers determined by the regression analysis, that is, it’s like when you fit a line to a trend in x,y data, the trendline formula has the form y = m*x + b.  The numbers in the denominator are like the m, the slope or sensitivity to each of the factors.

In terms of final refinements to the new standard, PHIUS has been operating an alternate certification path along the lines of the BA draft report for some months as a pilot program. In the February and March meetings, the TC did pass some changes in advance of broader implementation. The changes came from both the feedback and the pilot program experience.

One kind of comment that spoke to us was, “this isn’t disruptive but you might want to change this to align with, or not conflict with, the building code.” The most to-the-point answer to feedback about rules is what gets changed or upheld, so here is the list of changes the TC agreed on:

  • Source energy: The U.S. source energy factor for electricity is adjusted to 3.16 (aligns with IECC 2015). The residential source energy limit is adjusted to 6200 kWh/person.yr.
  • Air-tightness criterion: 0.05 cfm50/sf of envelope area or 0.08 cfm75/sf (testing at 75 Pa aligns with commercial code and U.S. Army Corps). If testing at 75 Pa, report the flow coefficient and exponent from the blower door tests (that way the software can extrapolate to 50 Pa for compatibility of figuring the natural air change rate for infiltration losses).
  • Non-threatening air leakage: If the air-tightness criterion is missed, and the extra leakage can be proven to be due to a non-assembly-threatening leakage element such as a vent damper, certification staff may allow that element to be taped off for the purpose of passing the air-tightness criterion. The un-taped test result must be used for the energy model.
  • Phase-in period:  Dual certification path continues until September 15, after that the old protocol is phased out for PHIUS+ 2015.
  • Break-in period: If a project is seriously constrained on one of the criteria, a case-by-case overage may be allowed on any one of the four space conditioning criteria, or source energy, for the next year.
  • Retrofit:  The retrofit criteria are the same as new construction, except for a case-by-case energy allowance for foundation perimeter thermal bridges or other such hard-to-fix structural thermal bridges. Provided the design is “damage-free” that is, low risk from a moisture point of view.
  • Add-on badge: for supply air heating and cooling sufficient, per static calculation, with the average ventilation rate no more than 0.3-0.4 air changes per hour. (That is, low peak heating load and low peak cooling load. Special recognition for those who favor and design to this particular “functional definition” of a passive building.)

And finally, Katrin’s long-awaited favorite:

  • Add-on badge: for source net zero.  Onsite renewable electricity generation above any that was already credited as coincident-production-and-use, counts towards net zero with the same source energy factor multiplier for electricity, i.e., 3.16.

To me the most substantial comment was along the lines that cost has been added on to the building delivery process, when you consider the labor of the CPHC, the pre-certification review, and the rater visits for quality assurance. The TC believes much of this concern is simply a matter of getting used to the requirements until it becomes the new normal, but we know that there is room for improvement on making the planning tools easier to use, and we will keep working hard on that.  Most commenters felt it was also very important to get the standard written out in human-readable form, not just encoded in WUFI Passive, and we will work on this as well.

Overall, we believe that PHIUS+ 2015 will make passive building more cost-effective across climate zones. The community’s collective experience informed all the work–so thank you all for all your input and hard work and again, thanks to everyone who took the time to submit formal comment. We’re excited to implement the new standard and believe it will dramatically increase adoption of passive building.

 

The North American Passive House Conference in San Francisco – a hard act to follow for NAPHC2015 (in Chicago)

Every year we say “This was the best passive house conference ever, we better stop now, we can’t possibly top this experience, the quality of the presenters, the “meat on the building science bones” presentations, technical details and specific construction solutions, cutting edge projects of all building types showcased throughout all climate zones, policy and government role discussions and incentives… and this year in addition to the Builders’ Hootenanny the Architects’ Hootenanny which, you might have guessed, was a hoot.

Let me take this opportunity to thank our community of longstanding CPHCs, PHIUS Certified Builders and PHIUS+ Raters who have shared this passive building path with us now for almost 10 years. It has been a pleasure knowing so many great folks with their hearts in the right place and a common characteristic: a determined pioneering spirit to make the energy transition in the way we build and live happen. Thanks to all passive building practitioners and to newcomers to the conference especially the international speakers from the UK and Japan.

Together you submitted nearly 100 abstracts and we had a hell of a time to choosing the best ones. We ended up with an unprecedented total of 72 sessions in 4 tracks this year, more than ever before (we cut the plenary short upon your request to get to the meaty sessions quicker and to have more of them).

Special thanks go to Sam Rashkin from the DOE, for his invaluable contributions to the tracks on government perspective and for the great partnership he and the DOE have provided to the PHIUS+ certification program over the past couple of years. Sam took time to be with us on the Sunday tour of passive buildings in the bay area, which was a lot of fun.

I would especially like to thank all of our outstanding pre-conference workshop presenters who covered topics in great depth, most popular were the Multifamily Palooza (kicked off by Chris Benedict who currently leads the field with the most passive projects in this sector realized), Passive Building Science with Joe Lstiburek (our unofficial lounge sponsor), packed the house closely followed by Mechanical Systems and commercial applications. Many thanks to the outstanding instructors who tackled more specific technical issues and new frontiers, such as efficient water systems design by Gary Klein, and Matthias Patzold from the Fraunhofer IBP and PHIUS staff presenting on dynamic energy modeling in WUFI Passive, THERM/windows modeling and PHIUS+ certification QAQC during the rater training. To all our presenters, pre-conference and main session: Thank you all so much! It would have not been possible without you!!!!

We owe many thanks to Michael Hindle, our charismatic Master of Ceremonies, and President of the Board of Managers of Passive House Alliance US (PHAUS). His opening speech was inspiring, artful and philosophical, The Passive House Alliance is now 16 chapters strong with 7 more in formation all over the country. It is starting to develop an impressive momentum regarding advocacy for passive buildings across the nation. Michael pledged to the membership that he would keep increasing member benefits and participation opportunities and closed with a call for action to join the many committees that have been formed to get the work done.

Michael also made a very well received announcement: the PHAUS  board has moved to remove any reference to a specific passive house standard from chapter founding documents. This decision rightly recognizes that since the inception of the passive house concept in the 70s in North America, it has undergone more than just one transformation and that evolution and learning will continue. It must continue to evolve for us to be successful. PHAUS leadership supports the new climate specific Passive Building standards brought forward by PHIUS as part of such evolution.

Bill Rose followed with the most thoughtful, most provocative keynote given at the North American Passive House Conference yet. Many of you came to me afterwards expressing that sentiment. He showed a short video recording from the early 70s of the researchers credited with formalizing the superinsulation/passive concepts. They worked at the Small Homes Council, University of Illinois at Urbana-Champaign in Illinois. The video reinforced the notion that the passive house community has a longstanding history here in the United States. He then showed a document written by the Nixon administration predicting peak oil and climate change to happen in 2010. It was a stunning piece of evidence that the issues had been known then, as well as the possible remedies outlined in the document. The document, then issued a clear call for action, recognizing the emerging passive community as having the best approach for reducing the demand side of buildings.

Rose made clear that facing the climate crisis means we also need to step up to transform the supply side of the system, coming up with strategies of how to keep the fossil fuel reserves in the ground and how to challenge the current economies that are all built around such assets. He ended provocatively saying, that we need to get to a point where we will be saying: “Energy (fossil fuels), what’s that?”

After the keynote and during all breaks, the exhibit hall was buzzing. A big thank you to all exhibitors of high performance materials and technologies! Every year the cast has been expanding significantly and new useful materials and systems manufacturers join the core group of providers. Thank you, without your products and services it would be impossible to realize passive buildings as well as we now do. Of course, also thank Exhibit Hall sponsor Bayer MaterialScience and our lanyard sponsor Hayward Lumber. Bill Hayward joined us on the tour and provides some great local background. Be sure to check the Hayward Health Home, a very cool initiative.

Achilles Karagiozis delivered the closing keynote. He spoke on the view forward, the implementation of passive buildings worldwide in all different climate zones and the challenges and responsibilities that come with it. He stressed the importance of dynamic modeling for accurate energy prediction results as passive building is applied in different climate zones. He cited an astounding example: WUFI Passive is now able to predict insulation material dependence on temperature on an hourly basis. And of course, this is important to assess hygrothermal performance of enclosures as well as to get the energy balances calculated with more accurate granularity. A great new age has arrived for us designers to manage our risks in designing passive buildings, thanks to the emergence of more powerful computing capabilities that make dynamic models feasible.

At closing, maybe best of all, the incredible sense of community of people who trust each other and know each other well:  We have been coming together now for almost a decade, reuniting at this amazing annual event working together to devise solutions for the North American market, its climate zones and building sector.

And this year, for the first time, the event was held in one of the largest and most exciting metropolitan areas: the San Francisco Bay area. This meant a significant step up from the previous conferences and importance in visibility of our community to city and government leaders, in California and beyond.  Passive building has turned the corner. And so has PHIUS as we were more than once told during the event by you.

PHIUS’ Senior Scientist Graham Wright’s presentation on new North American Passive Building Standards that are currently being completed under a DOE Building America grant was very well received: “This sounds like a really good program” was consistent feedback. The interest was so large that the session had to be moved from the break out room to the ball room. Most everybody was in support, not one negative comment! Kudos to excellent work by Graham Wright and a clearly laid out and scientifically founded argument by the tech committee.

And last but not least thanks to the PHAUS San Francisco chapter and John Sarter and Lizzie Adams from PHCA for helping to organize a fantastic tour of project on a beautiful Sunday in paradise: From multiuse building to state of the art office building to residential retrofit projects, it was great!

Thank you all for coming, for your contributions, participation and feedback on what to do better next year. Keep it coming so that the next act will be better yet again… see you in Chicago, details to come!

 

 

 

 

Last call for 2012 / pre-Challenge Home PHIUS+ projects!

Hello, it’s Ryan Abendroth here. I’m the Certification Manager at PHIUS. With the new year coming, it’s a good time to discuss the upcoming changes to the certification process and what it means for project teams pursuing PHIUS+ Certification.

Starting January 1, 2013, projects submitted for PHIUS+ Certification must meet the U.S. Department of Energy’s Challenge Home and the DOE/EPA Energy Star 3.0 requirements. This is a good thing—and will result in a streamlined, one-stop certification process, as I’ll explain later in the blog.

But, if you’re a CPHC with an ongoing project designed with the current certification requirements in mind, I encourage you to submit it for PHIUS+ Certification before the end of the year. Any project submitted before January 1 will be PHIUS+ Certified to current (2012) QA/QC requirements and will not need to also meet Challenge Home and Energy Star status. This will avoid any additional work on projects that were designed before the Challenge Home harmonization (this is especially important for projects that PHIUS first reviewed years ago, before PHIUS+ was established, but have been delayed).

For your project to be recognized as submitted you must supply a signed contract and PHIUS+ Certification payment. You’ll find the fee schedule here.

  • You can request the contract directly from me or simply email certification@passivehouse.us
  • You can sign, scan and  return the contract electronically or by snail mail to the PHIUS address: 110 S. Race, Suites 202, Urbana, IL 61801
  • Payment can be made by check via mail or via PayPal on the PHIUS Web site

For projects with expected completion dates in the next several months, I strongly encourage you to submit your documentation for certification before the end of the year—they likely were designed well before the US DOE and PHIUS established the new partnership.

Come 2013, earning PHIUS+ certification also earns the DOE Challenge Home designation.

Moving forward, I firmly believe that the upcoming changes streamline and simplify the PHIUS+ Certification process. In most cases, design changes will not be necessary for passive houses to achieve all three certifications. Currently, the QA/QC process for PHIUS+ includes a spreadsheet to be filled out by the PHIUS+ Rater in addition to the required tests of ventilation commissioning and blower door. With the new Challenge Home requirements, the PHIUS+ Spreadsheet will shrink in scope and complexity. The Energy Star 3.0 and Challenge Home checklists will take the place of some of the provisions currently in the PHIUS+ spreadsheet. You can download the new PHIUS+ spreadsheet here.

As mentioned above, starting January 1, 2013, all projects pursuing PHIUS+ Certification will be required to meet the specification for Energy Star and the US Department of Energy’s Challenge Home Certifications. Through the partnership between Challenge Home and PHIUS, there have been some exemptions granted within the Challenge Home and Energy Star requirements for projects pursuing PHIUS+ Certification. More news on these exemptions will be provided as soon as the updated Challenge Home documents are released.

Feel free to ask any questions here via comments here on the blog or by email at certification@passivehouse.us

Happy Holidays,

Ryan