Strengthening the Core

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With PHIUS+2018 we took a clear step forward in our commitment to being on the frontline of promoting sustainable energy use in buildings and reducing carbon emissions.

But passive building stakeholders have raised some valid concerns about PHIUS+ 2018 that deserve to be addressed.

The most important concern expressed is that PHIUS+ 2018 appears to move away from the core principle of passive building—that being conservation first and foremost. Rest assured: that principle remains at the core of PHIUS+ 2018. As with PHIUS+ 2015, the foundation of PHIUS+ 2018 is cost-optimized on-site conservation. That core principle is baked into the PHIUS+ 2018 standard, WUFI Passive and heating/cooling energy targets.

Cover image of Certification Guidebook and link to download PDF.

Click to review the update in Section 3.3 of the Certification Guidebook

PHIUS+ 2018 goes further by requiring steps toward net zero source energy, with a mind to carbon reduction. What’s new is that project teams now can also choose offsite renewable energy sources to meet the source energy target.

Despite that change, the core conservation principle never went away—conservation targets on heating and cooling energy still must be achieved using passive measures under PHIUS+ 2018 first.

Some of you have also raised concerns about situations where it’s difficult to go beyond on-site conservation. In particular, high unit density can be problematic. For these circumstances, PHIUS is adding the PHIUS+ Core certification path. Project teams can achieve PHIUS+ Core certification with strictly on-site measures. See Section 3.3 of the updated Guidebook for details.

And, we welcome your input—use the form below to comment.

Regards,

Katrin Klingenberg, PHIUS Executive Director

PHIUS+ 2018 Webinar Q&A

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PHIUS Senior Scientist Graham Wright and Certification Manager Lisa White answer questions that were submitted during and after the live PHIUS+ 2018 Webinar on November 8, 2018.

You can view a recording of the webinar at the PHIUS.org site.

*Note: Some questions have been edited for publication

Q: Has PHIUS started to look at overall GWP in the materials used to make these high performance buildings? To save the balance of the climate, reducing our emissions in the next 20 years is critical. Lots of XPS and spray foam make a low energy building but don’t do anything to help our climate goals.

A: The short answer is yes. We do have a GWP impact calculator for insulation. Its use is not required for project certification but we encourage it when we see large areas of XPS or SPF proposed. Our product certification program for construction systems has a requirement for a sustainability or health certification; there are several options recognized.

Q: Can you explain the exuberance concept?

A: We remain enthusiastic about the “tiny heating system” / “tiny heating bill” idea.

Q: Thanks for including Quebec Province! I believe in 2015+, all of North America was calculated according to a blanket value for cleanliness of the grid. Is 2018 adapted to different grids, and how do you deal with Quebec’s very cheap and clean hydroelectricity? Renewables are a tough sell here. Zero government incentives and at 7 cents/kWh, our energy costs would have to more than treble in order to make PV make financial sense.

A: In the standard-setting study itself we used the same factor all the time, but because the buildings were (almost) all electric, it canceled out. The PV generation is multiplied by the same factor as the usage, so source net zero is achieved with the same size PV array as for site net zero.

The philosophy is that CO2 emissions anywhere affect everyone everywhere. We all share one atmosphere, so by a principle of solidarity we should really use the world average source energy factor for electricity. That is, people with clean grids do not get to play “we’ve got ours” and use more energy. Even if your local grid is clean we want to drive additional action such as REC purchases that fund new clean energy projects. In certification we do allow the use of national averages, so we actually just request solidarity at the national level. Canada has a cleaner grid than the US overall, and thus Canadian projects will not have to take as many measures for net source energy reduction. The source energy factor for electricity in Canada is 1.96, whereas it is 2.8 for the US.

The electricity cost does affect some of the space conditioning criteria because higher energy prices justify more conservation measures and thus tighter targets. We calculate this with state-by-state averages, so Quebec projects will have less stringent targets than neighbors in Maine and Vermont.

 

Q: The word “townhouse” usually means a single-family building, but you seem to be using it differently.

A: The individual dwelling units are “single-family, attached”. That is, they share walls but not floor/ceiling. Speaking loosely, the whole row of attached units is the Townhouse, and the study building is 8 or 16 attached units.

Q: Is the mandatory minimum for window upgrades done because it wouldn’t be cost effective otherwise?

A: Yes. Window costs have come down but this still had to be forced in most cases. The starting points were still “in the money” though. There were a few times when the optimizer bought them on its own, but it took a long heating season and high energy price to motivate it. 

 

Q: Is this modeled EUI directly from WUFI Passive in the “Modeled vs. Measured” slide?

A: Yes, the WUFI Passive energy model used for certification.

Q: Do the new non-residential commissioning requirements apply to the common areas of residential buildings or only to all non-residential buildings?

A: TBD. Our current definition (for source energy target purposes) hinges on whether the spaces serve outside clients / customers or just the residents.

 

Q: Are you considering using the last 5 years of climate data vs ASHRAE to deal with global weirdness?

A: No, but we are working on future climate data for 2090 as an informational resource.

 

Q: Any comments on using low-iron glass (easily found in EU / just starting to appear in US)? Does the visible transmittance increase relative to ordinary US glass (which has a green tint to natural light)?

A: Alpen for a while had a low-iron glass option in their certified products, but they discontinued it.

 

Q: Instead of ignoring PV in competing with efficiency measures, why not look at PV with storage for the costs? This may not take care of seasonal differences, but it would take care of daily or weekly changes.

A: We may have have explored it if that was an option in BEopt, but it isn’t yet. Our current thinking is that what batteries do for you depends, in normal operation, on what the time-of-use rate structure looks like, and they are also good for you in outage situations. We are working on a calculation protocol for outages and waiting for utilities or other researchers to converge on time-of-use rate structure(s).

 

Q: Is there an ASHRAE 55 comfort analysis or PMV for PHIUS+?

A: The new window comfort calculator is based on relatively recent research on Predicted Percentage Dissatisfied specifically for draft at the ankle – it doesn’t just hark back to the PMV/PPD that was determined in 1970.

I (Graham) also wrote a paper for the 2016 conference looking at the radiant temperature effect of windows on comfort.

In certification we mostly take the same kind of simple view as in building code, e.g., “thou shalt maintain a dry bulb temperature set point of X and Y”. Sophisticated comfort analyses are more appropriate for workplace and nonresidential cases where clothing and metabolic profiles of occupants can be pinned down (as required by ASHRAE 55), and one might not have to worry so much about frail or sensitive occupants.

 

Comment: Adaptation is why I pursued CPHC in the first place!

Graham Wright: Thanks! Lisa presented on passive survivability at the Boston conference, and we will have more to say about this in the future.

Q: How does the new standard accommodate variable occupancy patterns/equipment usage in non-residential buildings?

A: With respect to the performance targets, as a first step, we will allow two different occupancies to be used to determine the annual demand targets vs. peak loads. Also, we can develop custom criteria for unusual situations (additional fee applies).

With respect to energy modeling protocol, it is already required to enter patterns for occupancy, ventilation and lighting, but this is mostly about getting the annual total energy right for source energy limit purposes.

 

Q: Please define HDD65, IGA, CDD50, TCD, IGCL and DDHR.

A: HDD65 = Heating degree-days, base 65 F;

IGA = Solar Irradiance, global, annual;

CDD50 = Cooling degree-days, base 50 F;

TCD = Temperature, cooling design day;

IGCL = Irradiance, global, cooling load design condition;

DDHR = Dehumidification design humidity ratio.

 

Q: If a project is considering registering under either 2015 or 2018, can we register under 2015 then change to 2018 (as circumstances change) without an additional registration fee?

A: Yes, you can always pursue a newer version of the standard. You are not able to pursue older versions if the contract date is later than the last day to submit under that older standard. In order to register for PHIUS+ 2015, the contract must be submitted before April 1, 2019.

 

Q: Are there updates to WUFI to accommodate the 2018+ standard? And when will it be available?

A: Yes, the next version of WUFI Passive will be released by the end of 2018. We will notify all of PHIUS’ mailing list.

 

 

 

 

 

 

 

 

Tierra Linda Brings Affordable Passive Housing to Chicago

Some forward-thinking architects and community groups have partnered with PHIUS to bring the benefits of passive building to the affordable housing market in Chicago.

Landon Bone Baker Architects (LBBA) and the Latin United Community Housing Association (LUCHA) held a public tour of the Tierra Linda passive house project on Wed., June 20. The tour drew a crowd of nearly 150 architects, designers, writers and curious neighbors.

While the project is well under way and set to be completed in October, city regulations nearly thwarted the idea in its early stages.

“Initially the city was skeptical about the passive house design,” said LBBA architect Dominik Soltys, “but once we explained to them what it would mean for the community then they were more receptive.”

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Other homes in the housing project are Energy Star rated, a more relaxed rating than the PHIUS+ certification, but cheaper upfront. ComEd will be monitoring the energy usage on the passive building against the Energy Star buildings to evaluate and compare actual energy performance.

The adoption of passive building design is growing exponentially in the affordable housing sector, with some states having already included passive building certification as part of their process of awarding tax credits for affordable projects.

According the the United States Federal Reserve, one in two renters in the City of Chicago is rent burdened, meaning that more than 30 percent of their income is spent on housing costs such as rent, utilities and repairs. Passive building is a perfect match for affordable projects, because it significantly reduces and attunes utility bills.

The 6-flat PHIUS+ certified building is located at 1812 N Drake Ave., in the center of a scattered development site in Chicago’s West Side. If all goes according to plan, the Tierra Linda project will be the first PHIUS+ certified multifamily  building in the state of Illinois. Before residents can move in, for quality assurance purposes, third-party PHIUS+ raters and verifiers will perform tests on the building to ensure that it is airtight and able to maintain a healthy air quality.

Lindsey Elton, Director of Rating Services at Eco Achievers, is in charge of testing the Tierra Linda project. During the tour, the PHIUS+ rater said she is excited for the future of passive building, and looking forward to being a part of this affordable housing project.

“We’re growing, PHIUS is growing. We’re pushing the envelope, no pun intended,” said Elton. “Your path to net zero is a part of our conversation.”

Why PHIUS? To Be Part of the Solution

Some inspirations from the Seattle conference to kick off 2018

At PHIUS, we’ve been at this passive building business for a good long while. And we’ve been inspired to see so, so many professionals join and build our community. Every year we’re all so busy that it’s pretty hard to find the time to just talk about why we’re all doing what we do. That’s why each conference is such a blast.

To capture a little of that fun–and inspiration–we asked a question of some attendees at the 2017 North American Passive House Conference in Seattle, Washington. The question:

Why do you build to PHIUS standards?

Here are some answers and comments we received–we hope you can relate to one or more of them, and please feel free to chip in your own answers in the comments section.

Elizabeth Correa, LMN Architects, Seattle: I design to PHIUS standards because it was a standard that allowed me to align my principles, my design principles, and ethical principles.

 

Sam Rodell, Rodell.Design, Spokane, Washinton: Building to the PHIUS standard is, I would say, our practice considers that to be our baseline and I think that anyone who builds today and does not consider the possibilities of what is happening here with building science wanders around in a dangerous territory of what I would consider to be professional negligence.

 

Lindsay Schack, Love | Schack Architecture, Bozeman, Montana/ Driggs, Idaho: I found PHIUS when I was researching affordable and high-performance wall assemblies for a client of mine. And once I found out about PHIUS, I went down this rabbit hole of learning building science, and now I can’t go back. I can’t, with good conscience, build to code anymore. I have to push farther.

 

Doug Farr, Farr Associates, Chicago, Illinois: Our practice is devoted to sustainability. We’re architects and we are striving to achieve PHIUS+ on a couple of projects, one is a new build and one is a rehabilitation. It’s challenging and frankly, that’s why I like it.

Schack: PHIUS, the institute, not only provides you with support and knowledge, it provides you with camaraderie, and I’ve learned from great professionals, and it has pushed my projects to a level that is gaining notice in my industry and where I live.

Correa: And that marriage between building science and architecture through PHIUS has made me passionate about architecture again and passionate about our mission to address the problems of climate change.

Farr: Some of the other systems which are also worthy and ambitious also are hard to do, but they all have what Kat always calls a ‘get out of jail free card,’ which is that you can always compensate for building a less efficient building by adding more PV or renewable energy.

Correa: And I realize that buildings being a large percentage of the carbon emissions problem and I don’t wanna be part of the problem. That is why PHIUS is especially important to me.

Farr: Passive House is the gold standard.

Correa: I’m part of the solution and I’m not any longer part of the problem.

PHIUS+: The path to positive energy

Become a PHIUS+ Professional and be a leader in the industry

 

Why PHIUS? Because Climate Specific Design = Quality Assurance

Why do you build to PHIUS Standards?

Asked at the 2017 North American Passive House Conference in Seattle, WA.

Lindsey Elton, ECO Achievers:  …E-L-T-O-N like Elton John…

I believe in PHIUS because the organization has taken an extremely detailed look according to our climate zone of what it takes to build a net-zero home or a net-zero building.

Peter Marciano, Legacy Buildings, New York, NY: I’ve come to the conclusion based on what I’ve built that there’s a lot of information out here. There are several passive house programs available. And, for me, having come to the realization that it has to be climate-specific because that’s what works. That’s what works in this nation. That’s what works in this country.

Marc Rosenbaum, EnergySmiths, West Tisbury, MA: I’ve been doing this for almost 40 years, and one of the things that PHIUS brings to the table here that are so amazing to me is people are interested in the actual performance of the buildings. They’re measuring them. They’re comparing them to what they thought they should do, and it’s a really terrific community that is sharing the information to make better buildings.

Elton: They’ve taken all the guesswork out, they’re doing the calculations, and they were smart about it. And we can employ this time after time after time again.

Marciano: If it’s not climate specific, I have had definite problems with certain aspects of my enclosure and certain aspects of my building. And I wouldn’t make that mistake again. I would definitely use a climate specific standard to establish… To build my next passive house.

Rosenbaum: And I think we all know why we’re doing it. We’re doing it because we care about the climate, we care about the kids, we care about other species besides ourselves. And we don’t talk about that. We talk about BTUs, and thermal bridges, and solar heat gain coefficients.

Elton: We’re firmly behind it, our company’s firmly behind it. We believe in it, and that’s why we’re here.

Rosenbaum: PHIUS has really created this community of people, who I think, care about each other’s learning, and share our successes and our failures, and it makes all of us better.

PHIUS+: The path to positive energy

Become a PHIUS+ Professional and be a leader in the industry