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.”

IMG_0931-2

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.”

Transitioning from PHIUS+ to the PHIUS+ 2015 Passive Building Standard

Lisa White, PHIUS Certification Manager

 

Lisa White, PHIUS Certification Manager

Lisa White, PHIUS Certification Manager

Certification Update: PHIUS will not accept PHPP v9 for PHIUS+ 2015 Project Certification

Up until now, Passive House Institute US (PHIUS) has allowed project teams pursuing PHIUS+ Certification to use one of two passive house modeling tools to model their projects: 1) WUFI® Passive, the passive building modeling software developed by Fraunhofer IBP in collaboration with PHIUS and Owens Corning, and 2) Passive House Planning Package (PHPP), the passive house modeling tool developed by the Passivhaus Institut (PHI). However going forward PHIUS will not be accepting the latest version of PHPP v9 for PHIUS+ 2015 project certification.

Since the release of the PHIUS+ 2015 Passive Building Standard in March of 2015, PHIUS’ standard now differs significantly from the PHI standard. Specifically, the PHIUS+ 2015 Standard uses climate-specific targets for space conditioning energy use (the first such passive building standard to do so), limits overall energy use for residential buildings on a per person basis (rather than a square footage basis), and now uses a different metric for air infiltration.

For the first six months after the PHIUS+ 2015 Standard went live, project teams could elect to pursue either the earlier PHIUS+ Standard or the new PHIUS+ 2015 Standard. All new projects registered after September of 2015 are required to pursue certification under the PHIUS+ 2015 Standard.

 

Modeling Tools for Certification

Since the release of WUFI Passive in 2012, PHIUS has stopped teaching PHPP software during Certified Passive House Consultant (CPHC®) training and began exclusively teaching passive building energy modeling with WUFI Passive. PHIUS has since trained over 1,100 building professionals in the WUFI Passive software to date. In conjunction with the release of the PHIUS+ 2015 Standard, Fraunhofer released WUFI Passive v3.0, which includes a “PHIUS+ 2015 mode”. This software is uniquely suited to PHIUS+ 2015 projects, the North American passive building market, and is available for free on the Fraunhofer website.

Previously, project teams could use either WUFI Passive or PHPP for PHIUS+ project certification, and PHIUS continued to accept both modeling tools even after the release of the PHIUS+ 2015 standard. However, this was not without extra effort from the PHIUS project reviewers, as each PHPP submitted for PHIUS+ 2015 certification required a bit of “jury-rigging” in order to verify compliance with the PHIUS+ 2015 Standard. This adds time, and likely an extra layer of confusion, to the certification process.

In October 2015, the PHI released PHPP v9[1]. While this new software offers a variety of updates and new calculation protocols, PHIUS feels this software is no longer appropriate to verify compliance with the PHIUS+ 2015 Standard. As these two passive building standards diverge, the verification software also suitably continues to diverge. This ultimately does not come down to which software is “better”, but rather is simply about which software tool is most appropriate for each standard.

PHIUS will continue to accept earlier versions of PHPP for PHIUS+ 2015 certification, from the “06-02-10” IP overlay of the 2007 PHPP up through PHPPv8.5, but will not accept PHPP v9 for PHIUS+2015 certification. Eventually PHIUS will only be accepting WUFI Passive for modeling of PHIUS+ 2015 projects, but the date for this has not yet been determined.

For project teams with completed PHPPs that would like to transition over to WUFI WUFI logoPassive, PHIUS is offering a new service for a “one-time conversion” of your project from PHPP to WUFI Passive. The flat fee of $1000 for this service also includes the creation of a SketchUp file for the building and a walk-through of the completed model with PHIUS Certification staff. Contact certification@passivehouse.us for more information.

If you are a CPHC who has been meaning to venture into the world of WUFI Passive, PHIUS offers WUFI Passive training programs at various locations throughout the year to help get you up to speed on creating your own models in the software. Visit the WUFI Passive Training page for more information and to register for upcoming trainings.

Lastly, keep in mind that modeling tools are a small (albeit integral) part of the big picture. Try not to lose sight of the overall goal, which is to build energy efficient and resilient buildings that help to reduce the carbon footprint of the built environment. Regardless of your program preference, every step toward these goals is a step in the right direction.

 

[1] PHI allows project teams to pursue certification under previous iterations of their passive house standard as well as earlier versions of PHPP. However PHI’s new PER metric (the PE metric was used previously) requires using PHPP v9, the only version of the software able to calculate this. Thus PHPP v9 is not yet required for all projects; a sunset date for older versions of the standard and software has not yet been determined. For more information, see the “Criteria for the Passive House, EnerPHit and PHI Low Energy Building Standard” document on PHI’s website.

 

 

About WUFI Passive 

WUFI Passive is a powerful modeling program that dramatically improves the quality and efficiency of the passive building design process for Certified Passive House Consultants (CPHC®). The software allows for calculation of both static passive building energy modeling, as well as dynamic energy modeling for comfort and hygrothermal analysis. The user-friendly interface allows for SketchUp & Revit import, incorporates a seamless toggle between SI-IP, and generates high quality results reports for communication with clients and the PHIUS Certification team. Learn more at the WUFI website.

 

About the PHIUS+ 2015 Passive Building Standard 

Developed in cooperation with Building Science Corporation under a US Department of Energy grant, the PHIUS+ 2015 Passive Building Standard is the first and only passive building standard based upon climate-specific comfort and performance criteria aimed at presenting an affordable solution to achieving the most durable, resilient, energy-efficient building possible for a specific location. PHIUS+ 2015 is also the only passive building standard on the market that requires onsite QA/QC for certification.

Buildings designed and built to the PHIUS standard consume 86% less energy for heating and 46% less energy for cooling (depending on climate zone and building type) when compared to a code-compliant building (International Energy Conservation Code IECC 2009), resulting in an overall site Energy Use Intensity (EUI) of approximately 10-20 kBTU/ft2 year.

Window comfort and condensation

 

Graham Wright

Graham Wright

At the 10th Annual North American Passive House conference in Chicago, Steven Bluestone and PHIUS’ Lisa White made a presentation about the design of the Beach Green North (BGN) project in New York City, a seven-story multifamily residential building of some 94,000 square feet and 100+ dwelling units. The design featured double-pane windows with R-5 glass and R-4 frames.

A number of people were surprised that R-7 triple pane windows were not in the design. Low performance windows can indeed lead to comfort and condensation problems, and we did look into that. Here, PHIUS Senior Scientist Graham Wright posts about window comfort and condensation, both for the BGN project itself and how that may inform the PHIUS certification protocol going forward.

Background

Performance of building components such as windows has not been in the category of “hard-and-fast” requirements for certification. The hard requirements have been on overall building performance – the “three pillars” of space conditioning loads, primary energy, and air-tightness.

Though we have been adding more requirements over time, window performance has remained in the category of recommendation, not requirement. Since 2013 we have been recommending window performance by climate according to this table. You can see that for zone 4A, we are indeed recommending an R-7 window.

To be a bit more granular about it, New York (LaGuardia climate) has 12-h mean minimum temperature of 6.44 F, which would require a window U-value < 0.16 Btu/h.ft2.F or R-6.3, to maintain interior window surface temperature of 60.8 F (within 4 C of a 68 F air temperature, assuming an interior surface film resistance of 0.74 h.ft2.F/Btu.)

In terms of comfort, the first line of defense is the limit on peak heating load. Window U-value has a strong effect on peak heating load and, as explained in the report on the standard-setting process for PHIUS+ 2015 , we now require that projects meet limits on both annual heating demand and peak heating load (same for cooling). Moreover, the model building used in the standard-setting studies had its window U-values constrained so as to maintain 60 F interior surface temperature under winter design conditions (12-hour mean minimum outside temperature).

Thus the peak heat load criterion for the building overall is predicated upon windows that good, and it serves as an indirect curb on bad windows, while allowing the designer some flexibility to meet the overall peak load in different ways.

That is working well for buildings that are not tremendously larger than the study building. But BGN is fifty times larger, in terms of floor area. In the standard-setting report, we anticipated that there would be consequences of applying the same energy-per-floor-area criteria to all sizes of buildings; that is, larger buildings with lower surface-to-volume ratio (or surface-area-to-floor-area ratio) would more easily meet the criteria. We opted for giving this allowance to larger residential buildings, because such forms of housing are more efficient in terms of their materials usage or embodied energy.

Because of that large-building break, the BGN design could meet the peak heat load criterion with windows as low as R-2.5. The best double-pane windows available are in the R-4 to 5 range and the team asked if those would be acceptable. So we did some additional calculations on comfort and condensation.

Comfort analysis

The comfort analysis was done largely using the ASHRAE Comfort Tool, a standalone software that allows you to put an occupant in a room, then compute the radiant and operative temperatures and the human comfort metrics Predicted Mean Vote and Predicted Percent Dissatisfied (PMV and PPD).

The comfort standards ISO 7730 and ASHRAE 55 are in agreement on fundamentals. Their development was coordinated and they share the same models for the PMV and PPD metrics for overall bodily comfort, as well as “local” discomfort on different parts of the body. ISO 7730 is focused on analysis and assessment methods. ASHRAE 55 draws pass/fail lines whereas ISO 7730 just makes recommendations; it sets up categories A, B, C of design criteria for consideration.  The ASHRAE 55 pass/fail lines correspond to ISO 7730 category B. In terms of overall body comfort, the criterion is less than 10% dissatisfied. (Even at a predicted mean vote of zero, that is, on average feeling neither warm nor cool, there are still 5% of people dissatisfied.)

Worth noting is that our protocol of modeling buildings with a heating setpoint of 68 F already pushes the winter comfort to the cool end of the acceptable range of Category B or ASHRAE 55, even if there are no windows in the room at all. The clothing and activity level of the occupants are factors in the PMV, but even with Clo=1 (long sleeves and sweater) and a little activity of Met=1.1 (seated, typing), in order to get a PMV near zero you need an operative temperature of around 22 C (71-72 F). The Building America default heating setpoint happens to be 71 F.

At 45% relative humidity (RH) and an operative temperature of 68 F, the PMV is minus 0.6 and the PPD is 12%. Because the operative temperature is approximately the average of the air temperature and the mean radiant temperature, it will be lower than the air temperature in the winter when the window surfaces are colder than the walls. Thus, under the scenario shown in the first column of Table 1, the lower setpoint for air temperature has used up the design margin for comfort, leaving none for windows. If the activity level is a little higher but the RH is a little lower, as in the third column, then there is some comfort latitude remaining to accommodate windows.

Table 1. Winter comfort at two heating setpoints.

Air temp F

68

71

68

71

Radiant temp F

68

71

68

71

RH %

45

45

30

30

Air vel ft/min

20

20

20

20

Met

1.1

1.1

1.2

1.2

Clo

1.01

1.01

1.01

1.01

PMV

-0.6

-0.2

-0.43

-0.08

PPD %

12

6

9

5

There are two ways to look at this

One is that, under our current recommended way of modeling things, the improved comfort that high performance windows would bring is taken back with the lower heating set point, traded to save energy.

Another way to look at it is that as a general point, really good windows really are required for comfort at a 68 F heating setpoint.

However, to use this type of analysis to derive an absolute minimum window surface temperature criterion from the comfort standards, it would have to be carefully contrived to allow any windows at all. One would have to be specific about the activity and clothing and activity level of the occupants at least in an average sense, and small differences could make the difference between say, an 8 F margin between the window surface and the air, to no margin at all.

For the BGN window comfort analysis we instead performed a relative comparison, first constructing a baseline scenario wherein the occupant comfort was close to neutral with no windows, and then adding windows and checking the difference in comfort.

Typical main-room dimensions for the Beach Green North project are 10 x 22 feet. There are corner rooms with one window on each of the two exterior walls. Windows are 3’ 3” wide and 5’ 2” tall. Geometrically, an occupant in the corner with the windows also near the corner would feel the greatest comfort impact.

Results:

Baseline scenario (See Figure 1):

Occupant is seated, quiet (1.0 met), typical winter clothing ensemble (0.9 clo). Air temperature and radiant temperature both 74 F, humidity ratio 0.010.

Comfort is almost exactly neutral: PMV -0.10, PPD 5%

Figure 1. Baseline comfort scenario

Figure1

 

Windows scenario (See Figure 2 and 3):

Room 22 x 10 x 8 feet. Occupant seated in corner 3.3 feet from each wall, facing the short wall. Window jambs are 2 feet from the corner on each side. Window inside surface temperature is 50 F, corresponding to window U=0.4 at 6.44 F outside.

Mean radiant temperature drops to 71.2 F. PMV drops to -0.30 and PPD increases to 7%. This is still within the ASHRAE 55 or Category B criteria range of PMV +/- 0.5 and PPD < 10%.

Figure 2. Mean Radiant temperature with windows in the corner at 50 F.

Figure2

Figure 3. Overall comfort in window scenario, shifts PMV 0.2 cooler.Figure3

Conclusions:

Going from no windows to U=0.4 windows caused the PMV to shift cooler by 0.2, and the PPD to increase from 5% to 7%.

There is also local discomfort to consider. Even if the whole wall was at 50 F, this would still be just within the acceptable range for cool-wall radiant asymmetry.

We communicated to the BGN team that windows up to U=0.29 would be acceptable, splitting the difference between U=0.18 and U=0.4 (figuring that the shift in PMV would be even less going from U=0.14 to U=0.29 than it would be going from no windows to U=0.4.)

One of the other benefits of keeping the window surface temperature up within 3 or 4C of the air temperature is that there is less pooling of cold air under the window, and no need for heat under the window to prevent discomfort due to head-to-foot temperature difference. Some loss of amenity is occurring in this respect, but we did not attempt to quantify it.

One interesting point is that head-to-foot is indeed one of the local discomfort criteria in both ISO 7730 and ASHRAE 55 (per clause 5.3.4.4.) but, in ASHRAE 55, none of the local discomfort criteria apply unless the occupants are at Clo<0.7 AND Met<1.3. With that low of a clothing level, they would not be overall comfortable at 20 C (68 F) air temperature anyway, so likely they are bundled up to 1.0 Clo and the local discomfort isn’t as important.

Anecdotal feedback has been mixed. Our Canadian friends tell us “no one is complaining about comfort here with R-6 windows” even where we would recommend R-8. Our Lithuanian colleagues say “double-panes are uncomfortable; no one uses double-panes in Lithuania.” Lithuania is 10 F colder than NYC though, with a 12-hr mean minimum temperature of 3.8 F below zero versus LaGuardia at +6.4 F.

As to the certification program going forward, the matter was brought before the full PHIUS Technical Committee at our October meeting,

For the time being, the Committee decided to refrain from imposing a “hard requirement” on inside surface temperature for winter comfort, or directly on window U-value, and to continue in the category of recommendation.

We have already collected the data to set recommended winter-comfort-based U-value maximums for all the climate locations on our criteria map, and could make those show up.

A possible approach for certification could be to require that those recommendations are followed but give an option to do a more detailed comfort assessment like the one shown above.  This very kind of material-cost versus analysis-cost tradeoff is done elsewhere in the program, for example with thermal bridges. One can do a conservative design following simple rules , or make an edgier design and do more engineering work to verify whether it meets criteria.   Such an approach would require the development of some additional calculation protocol.

Condensation analysis: Background

One of the “hard requirements” PHIUS has added pertains to avoiding mold growth on interior surfaces caused by thermal bridges. Even if a thermal bridge is tolerable in terms its impact on the space conditioning loads and demands, it is not tolerable if it can lead to mold growth on the inside. Our protocol follows ISO 13788, and one of our calculator tools follows its methods. Just as in calculating the energy impact of a thermal bridge, we make a THERM model of the detail. But instead of calculating the extra energy loss, the critical result is the point of lowest temperature on the inside surface, and the criterion is that at that point, the interior air, when chilled down to that temperature, should be at less than 80% relative humidity.

ISO 13788 addresses how to determine the appropriate boundary conditions – the outside temperature and the indoor relative humidity. This is based on consideration of the monthly average outside temperature and humidity for the climate. The outdoor humidity is added to an indoor source that depends on one of five building humidity classes from low to high.

For each month, a psychometric calculation is then done to determine a minimum inside surface temperature needed to keep the RH at the surface below 80%.

The critical month is the one in which that minimum surface temperature is farthest from the outside temperature and closest to the inside temperature, because that requires the detail to be the most “insulating.” This “surface temperature factor” (fRsi) of the building element is defined mathematically as

fRsi = (inside surface temp – outside temp)/(inside temp – outside temp),

with a surface resistance at the inside surface of Rsi.

(Usually the critical month is also the coldest month but not always – depending on the climate it might be in October, for example)

ISO 13788 also addresses assessment of condensation on “low thermal inertia” elements such as windows and doors, using a similar procedure, but with some differences: instead of keeping the RH below 80%, the goal is to avoid outright condensation (RH=100%), because windows and doors have impermeable surfaces that aren’t as subject to mold, but vulnerable to rot and corrosion if outright wet. But the outside design temperature is more severe – instead of a monthly average, it calls for the lowest daily mean temperature of the whole year.

For our BGN analysis, we:

1. Used the 13788 procedure for “low thermal inertia” elements to determine the required minimum surface temperature and fRsi to avoid condensation.

With an interior RH of 48% in the coldest month, the dew point of the interior air was 47.7 F, so the inside surface must be warmer than that.

2. We then did a one-dimensional calculation with the frame U-value at 0.28 to determine if that was the case. Instead of the lowest daily mean temperature, we used (for convenience) the ASHRAE 99.6% design temperature, as AAMA does for their Condensation Resistance Factor. This was 13.8 F.

With an interior temperature of 68 F, and an inside film resistance of 0.74 h.ft2.F/Btu, the inside surface temperature then is 68-(0.29*0.74)*(68-13.8) = 56.7 F, that is, 9 degrees above the dew point.

Of course, this does ignore the fact that the surface temperature could be lower right in the corner where the frame meets the glass, because of the conductivity of the spacer, but 9 F provides a comfortable margin. ISO 13788 does caution that one-dimensional calculations aren’t generally good enough, but it is a place to start. We will refine the “low thermal inertia” version of our 13788 calculator and publish that soon.

We’ve also been asked whether we can specify an NFRC Condensation Resistance rating (CR). The AAMA recently published a good summary paper [AAMA CRS-15] that explains the differences between NFRC’s Condensation Resistance (CR), AAMA’s Condensation Resistance Factor (CRF), and the Canadian temperature Index or I-value, per CSA A440.2.  All of these are 0-100% higher-is-better ratings, but they are not directly comparable to each other.

From that paper it is clear that the CRF and the I-value are the same kind of thing as what ISO 13788 calls fRsi – ratios that indicate how far some critical inside surface temperature is towards the inside air temperature. Therefore, if that data is available for a window of interest, those ratings could be compared directly to the required fRsi from a 13788 calculation for “low thermal inertia elements” for an indication as to whether a window is good enough in the climate location of interest.

The AAMA white paper indicates that the I-value is generally more conservative/stringent than the CRF due to differences in the temperature sensor placements. Both of these are physical tests.

AAMA provides an online calculator that takes a given outdoor temperature, indoor temperature, and relative humidity, and computes the dew point and the required CRF, so it is making the same kind of calculation as called for in ISO 13788. (The disclaimer for it makes many good points.)

http://www.aamanet.org/crfcalculator/2/334/crf-tool

The NFRC Condensation Resistance rating is more complicated and harder to interpret, except as a relative ranking. It is basically the percentage of the window frame, glass, or edge-of-glass area (whichever is worst) that is below dew point under the standard test condition temperatures, averaged over interior RH levels of 30, 50, and 70%. It is based on modeling rather than a physical test.

At the October Technical Committee meeting there was consensus on the general matter of setting a definite requirement to avoid condensation on windows.

The next issues then are: under what circumstances a window condensation check should be required in project certification, and what the passing criterion should be.

PHIUS’ Certification staff are working out those details and plan to phase in the requirement.

In the meantime, a determination about “when to check” should key on risk factors such as:

  • Window U-value significantly above the comfort requirement.
  • Frame U-value significantly above the glass U-value.
  • Presence of aluminum spacers.
  • Lo-e coating on the inside surface of the glass.

Our recommended passing criterion is that 1-D calculations on the surface temperatures or fRsi of the frame and the glass, or an AAMA CRF rating, should meet the ISO 13788 minimums at the ASHRAE 99.6 design temperature for the climate, with some safety margin, or that a CSA I-value meets it without a safety margin.

We will also consider adding to our window rating data the fRsi calculated at the worst-case location, the inside corner where the glass meets the frame.

 

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

 

Climate Data and PHIUS+ 2015

 

Adam2smAdam Cohen is a principal at Passiv Science in Roanoke, Va, a PHIUS CPHC®, a PHIUS Builder Training instructor, the builder/developer of multiple successful passive building projects, and a member of the PHIUS Technical Committee. With the release of the PHIUS+ 2015 climate-specific standard, Adam weighs in on the importance of climate data sets.

Project teams have always needed to be discerning about climate data sets they use in energy modeling.  Whether it’s WUFI Passive, Energy Plus, PHPP or any other software, the old adage garbage in = garbage out applies. Project teams always must analyze and make a call as to how accurate the climate file is.

For example, I worked on a Houston, Texas project a number of years ago and there were several climate datasets that were close and one that was very different. As a team, we had to decide how to approach this in the most logical and reasoned way.

Recently as I analyzed a Michigan project, I determined that my two dataset choices were “just not feeling exactly right” so I asked PHIUS’ Lisa White and Graham Wright to generate a custom set. I can’t know that this one is exactly right, but I know that it’s as accurate and “right” as we can make it.

Note that when multiple data sets are candidates, it is not just altitude that matters, but location of weather station (roof, ground, behind a shed, etc.). Ryan Abendroth blogged on the subject of selecting data sets (and when to consider having a custom dataset generated) and I recommend you give his post a read.

Since PHIUS+ 2015 is a climate specific standard, it’s all the more important to use the best available.  We all know that bad data is not exclusive to PHIUS (remember the Seattle weather debacle in early versions of the PHPP).

It’s incumbent on project teams to use science, reason and judgment in interpreting climate data sets. Being on the water, in the middle of a field or in the tarmac of an airport makes a difference.

In New York City, for example, we have an oddity: There are three dataset location choices.

A satellite photo of NYC with Central Park outlined. The climate date for the Park is substantially different than that for other parts of the city.

A satellite photo of NYC with Central Park outlined.

One is Central Park, and the PHIUS+ 2015 targets for that are substantially different than the others. But, counter to a Tweet calling into question the validity of the PHIUS+ NYC target numbers, they are different because the Central Park climate data is substantially different – probably due to vegetation countering the urban heat island effect. It has a dramatic and pretty fascinating effect on the microclimate, and the U.S. DOE has a nice read on the subject.

For project teams lucky enough to have access to multiple data sets for their location, by rational comparison, they should be able to make an intelligent decision to use a canned set or to have a custom set generated.

It also more important than ever that the PHIUS+ certifiers to examine the weather data provided by a project teams to see if the project team made a logical, rather then an easy selection of climate data.

In addition, we on the PHIUS Technical Committee will continue to collect and monitor data and will tweak certification protocols as we see the need. But, I remind all my fellow CPHCs that bad climate data sets are endemic in the industry and it is important that project teams make careful decisions and that they reach out to PHIUS staff to help when climate data sets just don’t seem right.