Guidance on Retrofits and Decarbonization for All Buildings

32tev__gEmbodied carbon is an important and complicated subject. Phius Senior Scientist Graham Wright helps sort it out and discusses Phius’ new REVIVE program in this post.

Let’s talk about retrofit, starting with the proposition that we need to decarbonize all buildings by 2050.

Stopping direct emissions is a good start; the electrification crowd is right about that. But only stopping direct emissions just moves the burden onto the utility/energy supplier, and they have to contend with transportation electrification as well.

The key question for the building sector, and for society at large, is how much effort/investment to put into increasing the clean energy supply, versus reducing the demand by such measures as passive building and heat pumps.  

The scale of the required transition is daunting no matter which way we approach it, especially considering that we have to do all of this utility infrastructure and building retrofit work without throwing off a lot of emissions in the process. The embodied carbon crowd is right about that, though I think a materials focus doesn’t go far enough.  

One way to get at the balance-of-investment question is with the idea of life-cycle cost. What mix of grid upgrades and building upgrades minimizes the total cost of getting the job done, on an annualized/life-cycle basis? I brightened up to this when it occurred to me that carbon could be included in that calculation by including a cost of carbon. Let’s use full-cost accounting!  

That price might be set based on the cost of, say, direct air capture of CO2, that is, at some point it becomes cheaper to actually pull the carbon back out of the air. The full-cost metric I am thinking of would include all of the following:

Tentative name: Annualized Decarbonization of Retrofitted Building Cost (ADORB Cost)

ADORB Cost = sum of the following components, each an annual/annualized cost:

  • Direct energy cost. E.g. site kWh * $/kWh = $
  • Direct building retrofit measures cost (material & labor) including building-level electrification cost. E.g. ft3 of stuff * $/ft3 = $
  • Social cost of carbon, upfront/embodied. CO2e kg * $/kg = $
  • Social cost of carbon, operating. CO2e kg * $/kg = $
  • Energy system transition cost (e.g. new utility solar + storage). $/MWh * MWh = $

The idea would be that a baseline cost in this sense is calculated for the scenario of continuing to operate and maintain the building as is for some decades. Any proposed retrofit should at least have a lower cost than that, hopefully much lower. Basically one designs as if there’s a carbon price. (In a baseline case I calculated for my apartment, 70 percent of it was the carbon cost of continuing to operate the gas furnace and water heater, even after the grid electricity was completely decarbonized).

This seems useful, but there are a few issues with it, therefore it can’t be our only lens. 

Issue 1 

It would not prohibit supply chain emissions from the retrofit work. Arguably the ideal is, call it Absolute Zero: No CO2 emissions occur anywhere in the building delivery/retrofit process, supply chain, or the building operating life, at any time. We need to decarbonize everything — the whole economy. In this view, the policy stance is that any carbon capture tech is devoted to removing carbon previously emitted, not keeping up with new work.  

All the current net-zero and carbon-neutral programs have this limitation. We can’t really do everything without emissions yet, so in order to convince ourselves we are zero there all these offsets and avoided-carbon credit schemes. I’m starting to agree with the youth climate activists that this is weaselly.  

Issue 2

At the system level, it’s tricky to use cost to decide grid-versus-building investment, because those costs in turn depend on which approach we decide to scale up in the first place. Commit to industrialized retrofit construction and those costs can come down. Commit to scaling renewable generation and transmission and those costs can come down.  

Issue 3

It’s not clear how to make this full-cost metric take into account that some things just can’t happen fast enough. For example, renewable generation and even transmission may not cost that much, but siting the required high-power transmission lines from remote western wind and solar farms to eastern cities might take too long.  

Issue 4

We’ve gotten into trouble across the board lately with our global economy by trying to minimize cost without regard to resilience. It’s more resilient to do extra things to reduce building loads rather than putting the ball in the grid’s court to both decarbonize AND stay up.  

McKeesport RetrofitTherefore, I am thinking that our new REVIVE Pilot program for building retrofit needs a number of different frameworks. I have listed them below along with a few possible elements of each:

Land use

  • Retrofit, replace/redevelop, or raze/rewild?
  • FEMA hazard assessment
  • Emerging climate hazard assessment (e.g. derecho, wildfire smoke)

Decarbonization

  • Cease direct emissions.
  • Use and generate renewable energy (reconsider off-site renewables framework).
  • Re-use high-embodied carbon structure.
  • Calculate a carbon score (no criterion, just how low can you get, i.e. without offsets).

Cost/Financial/Equity

  • Calculate ADORB cost, goal to at least beat the existing condition.
  • Use load reduction, grid interactivity and storage to financial advantage.
  • Limit the cost burden on low-income people.
  • Look to make policy cases for feebates, incentives.

Resilience 

  • Design for outages and known/emerging hazards.
  • On-site/local power, microgrids, on-site/local repair parts
  • Design for low loads.

Quality and Health

  • Assess existing deficiencies (EPA indoor air quality risk list).
  • Audits: tests, energy models?
  • Commissioning & documenting that goals are met (e.g. ASHRAE 202)

Phase planning

  • Scope includes operations, not just design.
  • Plan covers both an end state and interim retrofit phases.
  • Try to cover critical loads in the first phase.

I will have a bit more to say about this at PhiusCon 2021 this October 12-15 in Tarrytown, New York. The REVIVE Pilot program is in pilot phase, looking for sample projects, and the goal is to have an on-ramp in place. The general development strategy is to evolve from informational guidance to hard requirements in an orderly way, preferably without much backtracking.  

Our existing Phius Certification program for retrofit projects remains available through the Phius CORE REVIVE 2021 and Phius ZERO REVIVE 2021 programs, outlined in Section 3 of the Phius Certification Guidebook.

Regards,

Graham

Help Wanted: Identifying conditions that can complicate retrofits

32tev__gPhius Senior Scientist Graham Wright weighs in here with a guest post about some on-the-ground research he did regarding retrofits. Graham conducted a brief street-view survey of residential housing in Portland, Oregon (Glenfair, Glendoveer, Rockwood neighborhoods), and documented conditions that would complicate panelized retrofit solutions. He invites you to do the same in your neighborhood, and to submit what you find to advance research on panelized retrofit solutions.

It looks like I will be pivoting to concentrate my work on retrofit for a while. This is in connection with the Advanced Building Construction Initiative (ABC) of the U.S. Department of Energy. Under the program, RMI was funded to set up a collaborative and phius is a member. The vision shared at the recent summit is to figure out how to decarbonize ALL BUILDINGS by 2050. A study of the building typologies is underway, led by NREL.

It is already clear that single-family detached houses are the vast majority of buildings by number, they probably also dominate the aggregated “thermal loads” of heating, cooling, and hot water that comprise most of the energy/emissions savings opportunity.

The NREL data set does not have all the building properties that one would need to identify the technical barriers to deep energy retrofits. There is general awareness on the ABC team that the U.S. housing stock is very diverse and that this is a challenge to the concept of industrialized retrofit. So to get a better sense of this I spent a couple of hours looking at houses within walking distance of where I live in east Portland, Oregon. I looked for conditions that would complicate an exterior panelized envelope insulation retrofit, or that would complicate air-sealing. I looked at 33 houses and noted 30 separate conditions. These are assigned four-letter codes as shown in the table below. Some were much more common than others, such as attached garages, and some were so universal I did not even list them, such as gutters/downspouts.

My takeaway from this excursion was that the number of conditions that one would need to have a plan for is large but not endless. There are obviously some missing, such as balconies and widow’s walks. It’s not a large sample and I could only see one or two sides of the houses from the sidewalk. Many of the houses pictured are on crawl space foundations as indicated by vents, and that could also be considered an air-sealing complication, though I did not call it out here.

Here’s a slide show with problem conditions annotated:

 

Please send photos of houses near you! If possible, annotate conditions as I have in the gallery, using  the codes in the table below, or adding other conditions not listed, that also seem troublesome from the point of view of exterior retrofit and air-sealing.

Here are the problem conditions I classified, along with the number of cases I identified on my walking tour:

ACOD – air conditioner outdoor unit (3)
AGAR – attached garage (10)
CATV – cable tv line (1)
DISH – satellite dish (5)
DRYV – dryer vent (2)
E@RF – electrical mast through the roof (8)
EMTR – electrical meter (3)
EOUT – electrical outlet (1)
FENC – adjacent fence (13)
FCHM – fireplace chimney (17)
GCHM – gas appliance chimney (5)
GMTR – gas meter (3)
HOSE – hose bib / reel (3)
MLCA – mature landscaping close aboard (9)
MSXT – masonry extension from wall (5)
OV@R – overhang attached at roof (5)
OV@W – overhang attached at wall (5)
PBVT – roof plumbing vent (3)
PBCO – plumbing clean out (1)
RFVT – roof vent (4)
SKLT – skylight / sun tunnel (3)
SOFF – overhang with soffit (3)
STOV – wood/pellet stove chimney (1)
TCOM – telecom or mystery wall box (7)
THIC – change in cladding thickness (5)
TITE – can’t add wall thickness (20)
WART – wall art (1)
WBOX – window box (2)
WING – wing or fin wall (1)
XTLT – exterior light fixture (12)

RESNET 2012 Recap

Just a quick status report from the trenches, err, trade show booth: PHIUS just packed up the table at the RESNET 2012 trade show in Austin, Tex. The booth was generously sponsored by Jim Conlon of Elysian Energy in Silver Spring, Md. Jim was one of the first  folks to become a CPHCSM, and was among the first group of RESNET Raters in the country to take the new PHIUS+ Rater training last December; he’s now qualified to perform the PHIUS+ RESNET QAQC process. Thank you, Jim, for your work and your generosity!

PHIUS promoted its newly launched  PHIUS+ project certification to the RESNET stakeholders, who are the linchpin of the process. PHIUS+ RESNET raters perform passive house specific on-site testing protocols and generate HERS index numbers that accurately reflect passive house performance. PHIUS is offering a two-day certification training for experienced HERS raters to specialize in passive house and passive building QAQC and testing. Only passive houses that pass this rigorous quality assurance process receive the certificate.

During the conference, PHIUS held another 2-day class for raters: one day in the class room and one day on site. Yes, Austin

Take a video tour of Nicholas Koch's project.

already has two passive houses and one of them, Nicholas Koch’s retrofit project, was used for the on-site testing and the ERV balancing and commissioning protocol. The class had the special opportunity to use a new product from Minneapolis Blower Door; it can provide extremely low-flow ventilation air testing and balancing. Thanks to the company’s owner—Gary Nelson—instructors  John Semmelhack and Ryan Abendroth used equipment right off the trade show floor for PHIUS+ RESNET Rater on-site training.  Thank you, Gary!

Ryan and John also presented a conference session on Wednesday afternoon that outlined the PHIUS-RESNET, program details and benefits to raters and consumers.

Overall, RESNET 2012 was a great success with close to 1000 participants! Indeed, energy efficiency is on people’s minds and on government’s radar.

For me, the most important message was RESNET’s pledge to devote its resources in 2012 to make performance-based incentives a reality. This is awesome, of course, for everyone building to the passive standard, as these buildings—that offer maximumperformance—will receive maximum incentives.

Also very encouraging: lots of RESNET raters are extremely well-versed on passive house principles and aware of the PHIUS+ RESNET program. What better group of professionals to help build market confidence in quality-assured passive buildings? There was lots of interest in taking the two-day PHIUS+ RESNET rater training, and many raters also are interested in taking the CPHC training and becoming Certified Passive House consultants. On that subject, we’ll be announcing more PHIUS+ training sites and dates very soon!

I’m in Portland for the Passive House Northwest Spring Conference, and I’ll check in next from Boston at NESEA BE12 (if you’re going, sign up for my workshop on passive house mechanical systems).

Onward!