From Twin Countries to Twin Cities: China is Making Strides in Bringing Passive Building Mainstream

Katrin Klingenberg, PHIUS Executive Director

 

Passive House Alliance China’s 3rd China Passive Building Summit in Shanghai was followed up by a one-day expert meeting and workshop. The group rode out together to old town Shanghai, a nice area of the city consisting of mostly low-rise buildings. The fall weather had now finally turned a little nippy and drizzlier than the days before, and I was happy to have worn my jacket that day. Shanghai is unique: for two months out of the year (one each in the spring and fall), the temperatures are on the cool side, requiring no cooling and almost no heating, but the humidity is still too high to be comfortable.

The workshop was organized by Passive House Alliance China and took place onsite at a high-performance multifamily retrofit project located in a high-end gated community. Upon our arrival we were welcomed into a beautifully designed lobby where refreshments were being served to the invited stakeholders representing the construction industry and building science field from different cities in China. Following lunch, we had the opportunity to tour several of the completed high-performance apartments and begin to delve deeper into high-performance construction methods in mixed/humid climates with a focus on the cities in the Yangtze Delta. The main focus was on large-scale multifamily buildings, a rather typical and ubiquitous building typology throughout China.

If China and the US are country climate twins, then Shanghai is a close twin to Houston’s southeast Texas climate with the exception that Shanghai gets a little bit more rainfall. The most important challenges for passive design space conditioning solutions in these cities are not the thermal loads – it’s the humidity! Thermal loads are easily reduced to very low peaks by using passive design strategies such as moderate amounts of insulation (4 inches of mineral wool for a larger scale buildings will suffice), balanced ventilation with very good energy recovery efficiencies, excellent windows (double pane with thermally-broken frames), and passive level airtightness. But the high humidity load from ventilation during summer and the shoulder seasons can only be reduced so far. A significant dehumidification load remains, often during seasons when little or no cooling is required, as was the case while we were in China.

Improvements to the building envelope to minimize heating and cooling peaks also effects the ratio of sensible to latent cooling loads – resulting in the latent load becoming equal to or larger than the sensible load. While in less efficient buildings the sensible load far exceeds the latent load and can be taken care of by traditional cooling equipment, in highly efficient passive buildings it is the latent load that is now equal to or even dominant (see examples from Beijing and Hong Kong in the graphs below). This poses a new challenge for low-load comfort systems.

sensible-heat-ratio

The graphs illustrate how the sensible heat ratio decreases if the building envelope is improved for the climates of Beijing and Hong Kong. (slide credit: Hartwig Kuenzel, Fraunhofer IBP, NAPHC2015 keynote)

Climate specific targets also matter a great deal in this climate. In mixed climates, the right balance between heating and cooling targets becomes critical to avoid over-insulation and overheating risks. Window performance in mixed/humid climates needs to strike the right balance as well in order to not inadvertently increase cooling loads. Windows need to be optimized for both cases, heating and cooling, to perform at their best. In the climate of Shanghai as mentioned previously, good double pane windows with a lower solar heat gain coefficient and thermally broken frames are typically the right choice to meet comfort targets and to avoid contributing to overheating. Accurate assessment of internal gains must take into account culture, lifestyle, occupancy, and other factors as they have a significant impact on the overall energy balance of high-performance passive buildings.

In the case of China for example, cooking plays a major role in the vibrant Chinese lifestyle and culture, as we were lucky enough to experience first hand as our gracious hosts showed us the best and most interesting dining spots around Shanghai. Food is central to the culture and if folks are cooking a lot of flavorful and spiced foods in their homes in a climate with significant cooling loads, they will want directly vented kitchen exhaust hoods! Grease, odors, and heat need to get captured and thrown out right at the source. I was impressed to see a novel solution to this problem as we toured the retrofitted apartments. Each unit had two kitchens: one being the “real kitchen” with the big stove, prep area, and fridges which were separated from the main living space by sliding doors to minimize the negative indoor air impacts on the rest of the apartment, and the other one adjacent was an open kitchen concept with a bar for entertaining! What a brilliant idea (if you can afford it)!

Now, what about energy modeling? We have often said that more complex climates really should be modeled using dynamic whole building energy balancing tools such as WUFI Plus. What makes the climate more “complex”? Cooling and dehumidification is needed when the exterior temperature gets closer to the interior comfort zone and begins to fluctuate around it. The warm season is dominated by diurnally reversing heat and moisture flows – in during the cooler nighttime, and out during warmer daytime temperatures. Add moisture into this back and forth and it becomes really complex. To be able to accurately predict how components and the whole building will perform from an energy and hygrothermal perspective, the designer really needs to perform a dynamic whole-building energy model based on hourly data to make the right choices. In contrast, in a heating dominated climate, exterior temperatures are swinging far enough away from the interior thermal comfort zone so that heat and moisture flows are mostly flowing out. Static models are accurate enough for simpler climates such as this.

The graphs illustrate conditions for both heating and cooling/mixed climates. The static monthly balance method as employed by WUFI Passive is sufficiently accurate to predict energy use in a heating dominated climate. In cooling/mixed climates such as Shanghai and Houston, dynamic whole-building energy simulation (WUFI Plus) is recommended. (slide credit: Hartwig Kuenzel, Fraunhofer IBP, NAPHC2015 keynote)

The graphs illustrate conditions for both heating and cooling/mixed climates. The static monthly balance method as employed by WUFI Passive is sufficiently accurate to predict energy use in a heating dominated climate. In cooling/mixed climates such as Shanghai and Houston, dynamic whole-building energy simulation (WUFI Plus) is recommended. (slide credit: Hartwig Kuenzel, Fraunhofer IBP, NAPHC2015 keynote)

Hygrothermal wall performance checks should be best practice for passive designs in mixed/humid climates to avoid any kind of condensation risk. As China ramps up their energy efficiency efforts in varying climates to near passive building levels and experiments with materials it will be critical that these models are created as project teams might not be familiar with just yet or have no long term experience with this risk management in mixed/humid climates, which can lead to critical and significant failures.

Now, what about the high-performance apartment tour, where are the Chinese at with their high-performance solutions today?

I was thoroughly impressed with what they had already in place in terms of execution, performance, details, mechanical solutions, and – to top it all off – a standardized monitoring interface centrally located in the home providing constant feedback on thermal comfort and indoor air quality to the home owner including fine particulate matter (PM 2.5) and inside to outside air quality comparisons. In Shanghai it is often the case that outdoor conditions are worse than indoors due to high pollution levels.

The project we toured was a retrofitted five-story brick building that had been upgraded by adding a 4-inch layer of mineral wool exterior insulation, airtight layer, and a new clay tile façade. The reported tested air-tightness result was 1.5 ACH, which is very respectable for a retrofit! Space conditioning was solved in a very elegant and most comfortable way: a separate energy recovery balanced ventilation system with appropriate filtration and dedicated integrated dehumidification took care of controlling ventilation humidity loads and outdoor pollutants (as evidenced on the screen of the monitoring interface in the living room, see opening photo). Space conditioning was handled by a separate point source solution consisting of hydronic heating and cooling integrated into the room’s ceiling. Radiant heating and cooling is a more costly, yet very comfortable high-end solution. Controlled infiltration and humidity loads are key to this solution to avoid condensation. So is awareness by the homeowner. They need to be put on notice that they can’t cool the home and leave the beautiful lift and slide high-performance balcony door open at the same time!

The developer reported that the passive house approach works financially for them for the high-end market. As you might expect, two bedroom apartments were selling in the millions, as would be the case for similar real estate in any other cosmopolitan global city.

Can passive go mainstream in China?

If I may offer my personal prediction: the Chinese have taken a surprising global lead in fighting climate change and have identified aggressive conservation goals for buildings as a valid strategy. The government has passed mandates to local jurisdictions to find appropriate cost effective solutions. If China addresses the cost optimization of passive building measures based on varying climates, construction paradigms, and energy costs in China similarly to what PHIUS did in the US, then they should certainly be able to generate design guidelines aimed at presenting the most economical path to zero. At the rate that they are going, I believe China will bring passive building to the mainstream before he US does because they have the political will, effective materials and components, knowledge of building science and energy modeling, and cost effectiveness strategies to get there.

What about the state of typical mainstream construction in China?

From what we saw, most apartments in Shanghai already have their own air-to-air heating and cooling heat pump unit sitting on their balcony. Pair that common solution with good airtightness, balanced energy recovery with dedicated dehumidification, moderate amounts of insulation and appropriate hygrothermal wall design, good windows, and you are there.

It would be great to see China taking the lead!

 

– Katrin

10th Annual NAPHC – best party of the year, maybe ever…

Wow – was that a successful conference! It has been a week and I am still processing it all. Chicago was unlike any other conference — things did not slow down in the office after it was all over, they rather accelerated. It indeed appears we have reached a tipping point.

From more than one person I heard that it seemed that the quality of work, detailing expertise and technical knowledge, size of projects and complexity of building types had reached a new high. And, compared to the early years, we were not just talking theory and intentions—but what people had done! Really impressive.

LEFT: Dr. Hartwig Künzel giving the Day 2 Keynote -- RIGHT: Sebastian Moreno-Vacca participating in the Architects' Hootenanny (L-R: T.McDonlad, T.Smith, J.Moskovitz, Sebastian, ?)

LEFT: Dr. Hartwig Künzel giving the Day 2 Keynote — RIGHT: Sebastian Moreno-Vacca participating in the Architects’ Hootenanny including (l-r): T.McDonald, T.Smith, J.Moskovitz, Sebastian, C.Hawbecker)

New modeling tools such as WUFI Passive (Technical keynote Hartwig Künzel, day two) are making building science interrelationships more visible and intuitively understandable. WUFI Passive is enabling CPHCs to optimize designs using “hygrothermal mass” (ever heard of that?) to optimize humidity loads and even to inform design decisions overall (as Sebastian Moreno-Vacca illustrated in his session) to create a unique architectural language! How cool is that! Science, heat fluxes and thermal dynamics begin to shape architectural form.

Dirk Lohan, Principal, Lohan Anderson -- Welcomes conference attendees to Chicago

Dirk Lohan, Principal, Lohan Anderson — Welcomes conference attendees to Chicago

Dirk Lohan—Mies Vander Rohe’s grandson, and an extremely accomplished architect in his own right—hinted at this development during his welcoming remarks.

“I believe that we will begin to see as beautiful what also is energy-conscious,” said Lohan.

Supported by the John D. and Catherine T. MacArthur Foundation

But maybe the most significant news is the explosive development in the multifamily affordable housing sector. It is seeing significant growth, interest and pilot developments going up in many places of the country. Thanks to the support from the John D. and Catherine T. MacArthur Foundation, we were able to make this our core topic for the conference and will be able to actively provide support to the affordable development community.

The pre-conference sessions included a daylong affordable housing Hootenanny that brought together successful affordable, multifamily housing project teams together who generously shared lessons learned and experience. Four different project teams presented during an intense full day. The morning and afternoon presentations drew full rooms of affordable housing developers who soaked up the information and had terrific, incisive questions

The same teams presented again during the core conference breakouts in a more condensed form for those who were unable to attend the hootenanny. In addition, there were more presentations on even bigger size affordable projects in progress:

  • A 101 unit affordable development in New York now under construction in the Rockaways (Steve Bluestone, Bluestone Org.)
  • A planned affordable retrofit of a 24 story historical brick building in Chicago (Doug Farr, Tony Holub from Farr and Assoc.), the Lawson House.
  • 24 story residence hall under construction in NYC (Matt Herman, BuroHappold)
L-R: Steve Bluestone presenting with Lisa White, Doug Farr, Matthew Herman

L-R: Steve Bluestone presenting with Lisa White, Doug Farr, Matthew Herman

Really amazing stuff.

Katherine Swenson

Katherine Swenson, Vice President, National Design Initiatives for Enterprise Community Partners — Day 1 Opening Keynote

Of course this growth has been fueled by forward-looking programs that recognize that energy efficient homes make so much sense for affordable housing developers/owners and dwellers. Katie Swenson from the Enterprise Foundation was a breath of fresh air–dynamic, positive, and motivating opening keynote. She explained that in her and her organization’s eyes energy is a critical part in assuring not just housing for people—but healthy housing! “Health is the new green,” she said, and of course passive housing delivers here with excellent comfort, indoor air quality and the added bonus of resiliency when the power goes out. Katie announced that the Green Communities criteria had just included PHIUS+ 2015 certification as one of the highest energy point options.

Other affordable housing agencies also have made a move: the Pennsylvania Housing Finance Agency (PHFA) awarded bonus points in its last round of selecting projects for Low Income Housing Tax Credits. More recently the New York State Homes & Community Renewal (HCR) effort was mentioned in a release regarding energy efficiency measures from the White House. Those agencies now directly encourage passive building standards in their RFPs. Remarkable!

Sam Rashkin, U.S. D.O.E. -- Closing Plenary Keynote

Sam Rashkin, U.S. D.O.E. — Closing Plenary Keynote

On the other coast. Seattle just amended their multifamily building code to allow additional floor area ration (FAR) for projects that meet the PHIUS+ 2015 criteria. That’s a significant incentive for developers.

Things are cookin’!

The core conference, as usual, was chock full of goodness. There were examples of how the new PHIUS+ 2015 climate specific passive building standards helped to optimize costs both here in North America (presentations by Chicago’s Tom Bassett-Dilley, Dan Whitmore, and) and internationally (Günther Gantolier from Italy). There were nuts-and-bolts presentations on wall assembly solutions (Tom Bassett-Dilley again), air and water barrier best practices (Marcus and Keith). And, the Builders Hootenanny—led by Hammer & Hand’s Sam Hagerman, focused on component challenges such as sourcing airtight FDA approved doors for commercial construction.

The U.S. DOE’s Sam Rashkin closed the conference with an unexpected message: he suggested that we needed to rename a few things to facilitate behavioral change. He posited that ZERH, LEED, PHIUS and other green building programs are essentially fossil fuel use rehab centers trying to rehabilitate an addicted nation and to show how it can be done differently. He received a standing ovation.

A few more comments on pre-conference workshops – three WUFI Passive classes drew almost 80 people and they all were super happy throughout the two days! Who would have thought! Happy people energy modeling!

LEFT: Marc Rosenbaum's lecture on Renewables -- RIGHT: Joe Lstiburek on Multifamily Building Science & HVAC

LEFT: Marc Rosenbaum’s lecture on Renewables — RIGHT: Joe Lstiburek on Multifamily Building Science & HVAC

Marc Rosenbaum single-handedly won first place in registering the most people for his class to connect passive principles with renewables to get to positive energy buildings (the logical next step).

Joe Lstiburek placed a close second (sorry Joe) and did a phenomenal job in covering ventilation concerns in large multifamily buildings. Rachel Wagner showed the most awesome cold climate details that I have ever seen. Galen Staengl took folks on a spin to design multifamily and commercial mechanical systems.

And Gary Klein topped it all off by reminding us that without efficient hot water systems design in multifamily, no cigar!

Thanks to all presenters and keynotes! You made this an excellent and memorable event.

I have not even mentioned the first North American Passive Building Project Awards—the entries were just beautiful projects—check out the winners here. I must mention the overall Best Project winner of 2015, as I believe this is pivotal: Orchards at Orenco. What a beautiful project, the largest fully certified PHIUS+ project in the country to date, a game-changer, underlining affordable multifamily projects on the rise.

I’m extremely happy that the Best Projects winners for young CPHC/architects was a tie, and both winners are women! Congrats to Barbara Gehrung and Tessa Smith! Go girls, you are the next generation of leaders!

L-R: Best Overall Project: Orchards at Orenco; Best Project by CPHC under 35 (tie): Island Passive House, Tessa Smith; Best Project by CPHC under 35 (tie): ECOMod South, Barbara Gehrung

L-R: Best Overall Project: Orchards at Orenco; Best Project by CPHC under 35 (tie): Island Passive House, Tessa Smith; Best Project by CPHC under 35 (tie): ECOMod South, Barbara Gehrung

One last note on a thing: Passive building people know how to party while devouring the most challenging, inspiring energy science, details, philosophies (Jevons paradox – Zack Semke’s fascinating lunch keynote) from the field.

And the architectural boat tour on Saturday to top it all off was almost surreal. When we were all out on Lake Michigan and the fireworks went off over the magnificent skyline, I thought, “that’s how we roll :).” Plus, the docent from the Chicago Architecture Foundation was a font of information, and even long-time Chicagoans learned a lot along the way. If you weren’t there, you missed the best passive building party of the year, maybe ever. (But we’ll try to top it, promise.)

Finally, for the crew that just can’t get enough, the Passive Projects Tour on Sunday was, as always, an enormous hit. Tom Bassett-Dilley and Brandon Weiss put together an array of completed and in-progress projects that generated a buzz at every stop. Thanks to Tom and Brandon and to PHA-Chicago for all your help!

Cheers!

Kat

 

Public Comment Opportunity: PHIUS+ Certification for Multifamily Performance Requirements (v2.0)

Chris McTaggart, PHIUS+ QA/QC Manager, wants your feedback…

Dear PHIUS/PHAUS community members,

Adoption of Passive House Institute US (PHIUS) PHIUS+ certification is growing rapidly. Of particular interest is the application of PHIUS+ certification for multifamily buildings. With several projects already certified or in the process of construction, and several more projects in the design phase, PHIUS expects certification of multifamily buildings to be one of the leading growth sectors for high performance, low-energy buildings moving forward.

With this in mind, PHIUS has created updated draft standards for certifying multifamily projects. These updated standards are intended to replace previous guidance offered by PHIUS for certifying multifamily projects. PHIUS is seeking review and comment from all vested stakeholders on these draft standards with the intent that a finalized version shall be released in Q2 2015.

The updated PHIUS+ Certification for Multifamily Performance Requirements (v2.0) contain several improvements to language regarding the specific performance modeling and testing expectations for certification of multifamily projects, including:

  • Modeled energy performance criteria
  • Infiltration testing requirements/protocol
  • HVAC testing/balancing requirements
  • Sampling protocol for dwelling unit-level testing/inspection
  • Additional onsite testing/inspection requirements

To create these draft guidelines, PHIUS solicited feedback from several constituents who are actively involved in the certification of high performance multifamily projects. These comments helped inform the standard development process, and the goal is that the most fundamental areas of need for clarification and formalization have been addressed.

Please take the time to read the attached PHIUS+ Certification for Multifamily Performance Requirements (v2.0) document below and make comments by June 8, 2015. Use the comments section below or email your input to certification@passivehouse.us

Thanks,

Chris McTaggart,  PHIUS+ QA/QC Manager

From passive house to passive buildings–what’s new and how manufacturers are stepping it up

BE15banner-LARGE

Exciting times indeed for passive building in the United States: Passive design principles that originated here and in Canada are all grown up and making a furious comeback. Policy makers, researchers and scientists, builders and designers are all embracing passive building in their everyday practice.

And as always, the growth is evident here at NESEA’s annual high-performance tour de force: NESEA BE15. A quick recap: Passive Building Place–a concentration of passive building component exhibitors, and the tour of their offerings, is in its fourth consecutive year. For those who remember, we started my first blog on the NESEA trade show focusing on passive house products in 2012. Passive building was still tiny then compared to what it has grown into now.

PHIUS and its membership organization the Passive House Alliance US (PHAUS) – the leading passive building research institute and alliance in the US – is the anchor of Passive Building Place for the fourth straight year.

NESEA never stands still. In its topic selection for conference workshops and presentations it continues to ask the tough questions and pushes the boundaries. I am talking about the passive building standard adaptation work we have been doing on Tuesday in a half day workshop. On Wednesday afternoon as part of the core conference I’ll be presenting about very exciting multifamily developments specifically. The Passive Building Place has become a mainstay and is expanding every year with new manufacturers who have recognized that passive building will be a significant driver for high performing materials and components.

Larger projects like Orenco Orchards in Eugene, Ore.,  by CPHC® Dylan Lamar and GreenHammer are coming on strong–they need more manufacturers to step up to the multifamily and commercial passive building market.

But, as multifamily and commercial projects come on strong, we see hesitation amongst manufacturers regarding new components and material needed for larger building developments. This follows the past trend with single family passive homes: the architects and CPHC®s (Certified Passive House Consultants) have taken on the design of the first larger buildings find themselves ahead of the curve.

While this might sound glamorous to some, in practice it is quite a challenge for the teams. Architects are out to make ambitious reductions in energy and carbon with large buildings, and they need appropriate high performance components. In principle, much of what’s been learned and accomplished in single family applications is transferable. Ideally, however, manufacturers will develop turnkey and warranted solution packages for multifamily and other large buildings. What about superinsulated thermal bridge free airtight curtain wall systems? Is this too much to ask for?

Here’s a good place to start: At last year’s 9th Annual North American Passive House Conference in San Francisco, five leading multifamily passive building teams came together for a presentation.  The one component they all wanted was a fire-rated door, that complies with ADA requirements of a low threshold, is airtight and has exceptional thermal performance comparable to the passive house windows that have taken the BE Passive Building Place by storm over the past few years.

To see what’s cooking this year, we are back for another tour of the trade show with you! I will have the pleasure of guiding a tour on Wednesday, March 4 beginning at 5.30 pm just before the boat tour. We’ll be visiting exhibitors who offer products and components germane to the passive building community. We will stop at selected passive building place exhibitors and Passive House Alliance sponsors inside and outside Passive Building Place. Because there are so many it’s impossible to visit all–instead we’ll focus on innovations and a more in depth conversation of 5-10 minutes discussing the manufacturers’ products.

Also different this year:  We will take the investigative role and instead of highlighting the passive building products we’ve seen in past years, we will challenge vendors with a different question: What are you doing to support larger passive building developments? Are you seeing the effects from it in your practice and what are you doing to respond, to prepare for it? Are there new offerings in the pipeline? What are designers asking for, what is missing?

Our goal is to identify the gap so that we can fill it. We like to inspire manufacturers to take the growth in passive building seriously. Please join us on this tour to hear from manufacturers what they are hearing and to ask the right and tough questions to inspire more high performing systems development for larger U.S. passive buildings.

Twenty-four exhibitors are joining us this year in the Passive Building Place or elsewhere on the floor–they include sponsors of PHAUS, firms with PHIUS certified professionals on staff, firms offering PHIUS verified windows or doors, or that are collaborating with PHIUS/PHAUS otherwise. Those partners are listed here:

475 High Performance Building Supply (Booth # 759)

Auburndale Builders (Booth # 913)

Bright Build Home (Booth # 549)

Conservation Services Group (Booth # 709)

Fraunhofer CSE (Booth # 660)

H Window/Energate (Booth # 642)

Huber Engineered Woods (Booth # 743)

Klearwall Industries LLC (Booth # 862)

Intus Windows (Booth # 624) PHAUS Green Sponsor

Marvin & Integrity Windows (Booth # 939) PHAUS Silver Sponsor

Mitsubishi Electric (Booth # 707) PHAUS Silver Sponsor

New England Homes by Preferred Building Systems (Booth # 919)

Passive House Institute US/Passive House Alliance (Booth # 753)

Pinnacle Windows Solutions (Booth # 763)

PowerWise Systems (Booth # 814)

PROSOCO Inc. (Booth # 949) PHAUS Green Sponsor

Roxul (Booth # 860)

Schock (#636)

SIGA Cover, Inc. (Booth # 620)

Steven Winter Associates (#844)

Stiebel-Eltron Inc. (Booth # 749)

Yestermorrow Design/Build School (Booth # 1036)

Zehnder America, Inc. (Booth # 864) PHAUS Friend Sponsor

Zola Windows (Booth # 755) PHAUS Friend Sponsor

 

We won’t have time to stop at all passive building component vendors, but we urge you to stop check them all out as you find time. Make sure to stop by:

Dryvit (Booth # 430)

Enovative (Booth # 945)

European Architectural Supply (Booth # 727)

Fantech (Booth # 828)

Foard Panel (Booth # 830)

Green Fiber (Booth # 717)

Led Waves (Booth # 628)

Main Green Building Supply (Booth # 622)

Retrotec (Booth # 541)

Sanden International (# 563)

Schock USA (Booth # 636)

Tremco Barrier Solutions (Booth # 719)

Viessmann Manufacturing (Booth # 565)

Yaro DSI (Booth # 638)

Thank you all for participating in this and putting your weight behind this exciting emerging construction market. Again, you are true leaders in this market transformation towards high performance building products that is so needed to achieve zero/positive energy buildings through passive design. Thanks again for joining!

And have a great BE15!

Comments on climate-specific standards study now open

ClimateSpecificColor
In cooperation with Building Science Corporation, under a U.S. DOE Building America Grant, the PHIUS Technical Committee has completed exhaustive research and testing toward new passive house standards that take into account a broad range of climate conditions and other variables in North American climate zones and markets.

This report contains findings that will be adapted for use as the basis for implementing climate-specific standards in the PHIUS+ project certification program in early 2015. Furthermore, as materials, markets and – climates – change, the PHIUS Technical Committee will periodically review and adapt the standard to reflect those changes.

  • We invite formal comment on the science. Please use this online form to submit. Deadline for formal comment: January 16, 2015.
  • Formal comments will not be public, and are for Tech Committee review only. (The Tech Committee or PHIUS staff will contact you for permission, should we be interested in publishing your comments.) All formal comments will be reviewed, but we cannot guarantee an individual response.
  • Passive House Alliance US Members: An online informal discussion forum is available to all members. The forum discussion will be visible to the general public, but only PHAUS members can make comments. Comments on the discussion forum are not guaranteed to be reviewed by the Technical Committee.
  • If you are not a PHAUS member, use the blog comments section below. Comments on the blog cannot be guaranteed to be reviewed by the Technical Committee. To ensure Committee review, use the online formal comment form.