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

It’s Here! The Phius Certification Guidebook v3.0

SONY DSCIn this week’s blog, Phius Associate Director Lisa White introduces the Phius Certification Guidebook v3.0 and explains how to get the most out of the newest guidebook iteration.

The Phius Certification Guidebook is the one-stop-shop for all things related to the Phius project certification program.

The guidebook contains information ranging from Tips for Designing a Low Cost Passive Building to Energy Modeling Protocols and What to Avoid. It continues to evolve alongside Phius’ growing certification program and standard updates. 

Guidebook CoverOne great reason to certify a project is to share knowledge with the passive building community, which accelerates growth. This guidebook is the keeper of that knowledge as well as lessons learned from the expanding base of certified projects. The Phius Certification team receives a myriad of questions from project teams related to unique circumstances and first-time design decisions that often require developing new guidelines and protocols to be applied on future projects — and those end up in the Guidebook. On top of that, the detailed review of projects throughout design and construction illuminates opportunities for the certification team to improve the guidance we provide to our constituents.

Version 1.0, released five years ago to support PHIUS+ 2015, clocked in at 87 pages. Version 2 followed to support PHIUS+ 2018 at 157 pages, and the most recent update, Version 3, supports Phius 2021, with 190 pages. The guidebook is a key resource for Phius professionals — but we’re often told it’s too long! I’m certain it can feel much shorter, and be incredibly useful, if you know how to navigate it. Anyone can get around a big city with the right map!

View this Table of Contents: Updates Summary which outlines what is new and updated in v3.0.

The document is split into 8 main sections followed by appendices.

The Sections

  • Sections 1 & 2 contain high-level information that is invaluable to first-time project teams and building owners/clients.
  • Section 3 is arguably the most important section, outlining all the certification requirements. Under Phius 2021, there are substantial updates to this section, most notably outlining the requirements of the performance and prescriptive paths side by side, as well as comparing and contrasting how each path handles items such as passive and active conservation strategies.
  • Sections 4 & 5 are key for setting expectations and understanding the workflows and fees associated with the certification process. There is a great high-level graphic showing three phases of certification steps at the beginning of section 4.
  • Section 6 is chock full of detailed energy modeling protocol. This section is laid out in order of the WUFI® Passive tree structure, guiding modelers top down with information ranging from early design defaults to detailed inputs for unique situations.
  • Sections 7 & 8 outline monitoring building performance as well as additional certification badges available. 

The Appendices

    • Appendix A is a consolidated resource about renewable energy. It explains how it can be used in the calculation of source energy use, and guidelines for procuring off site renewable energy.
    • Appendix B is likely the most often overlooked section, while also the appendix most referenced in project certification reviews. This appendix outlines the prescriptive approach to achieving moisture control in opaque assemblies. This most recent update splits this appendix into four types of guidelines: general, for walls, for roofs, and for floors. Do yourself a favor and vet the assemblies used on your next project (certifying or not!) against the guidelines listed here.
    • Appendices C & D are carried over from the previous version, outlining how to assess when a cooling system is recommended (App C) and internal load equipment tables for non-residential buildings (App D).
    • Appendices E, F, & G are great resources for the Phius Certified Rater or Verifier.  Appendix E is the Phius Certified Rater/Verifier manual. It outlines detailed technical inspection and field requirements, post-construction requirements, as well as how to maintain or renew the professional credential. Appendix F describes the procedure to prepare the building for airtightness testing, while Appendix G provides the onsite testing requirements for multifamily buildings.
    • Appendix H describes the Phius 2021 target setting updates, similar to what was found in the previously released “Standard Setting Documentation”
    • Appendix I is new to this version, and holds important information — most notably tips for passive building design about keeping costs low, assembly & window selection, and ventilation systems.
    • Appendix J talks about Co-Generation on-site, and how it affects the source energy factor for natural gas or grid electricity used on-site (depending on how the co-gen is prioritized). This is carried over from a previous version.
    • Appendix K is brand new, outlining definitions and requirements for electric vehicle charging infrastructure to supplement the requirement outlined in Section 3. EV capability is required in some fashion for all residential Phius 2021 projects.
    • Appendix L is also brand new and only applies to Phius CORE projects, as it describes electrification readiness requirements for combustion equipment. As a reminder, fossil-fuel combustion on-site is only permitted for Phius CORE projects, and not allowed for projects pursuing Phius ZERO or Phius CORE Prescriptive.
    • Appendix N closes out the document with normative information. Most notably, N-7 describes many of the underlying formulae for the Phius CORE Prescriptive path which is brand new to Phius 2021. It also contains the formulas and calculation methods used for lighting and miscellaneous electric load calculations, for example.

General Tips

  1. Utilize the Table of Contents and click to the section you need.
  2. Use the ‘find’ function (Ctrl+F) when in doubt of where to look to search for keywords. If taking this route, take note of what section your results are in – for example, is it a requirement or just informative?
  3. Bookmark the Guidebook link! (And follow Phius’ newsletters to be sure you’re aware when new versions are released).
  4. If you are the…
    1. Building Owner/Client — read Sections 1.1-1.4 and Appendix I-1 and review the graphic on the first page of Section 4.
    2. Project Team Member — read through Section 3 one time in its entirety if Phius Certification is a goal of the project. It’s only 18 pages, there are tables and pictures, and you can make it an excuse to have a beer.
    3. Project Submitter — read through Section 4 one time to set expectations, you will be happy you did. Also note Section 2.2, “Yellow Flag” items.
    4. CPHC / Energy Modeler — bookmark Section 6 for reference as you work through the WUFI Passive model.
    5. Phius Certified Rater/Verifier — bookmark Appendix E & F.
    6. One who loves the nitty gritty of passive building — print it, read it cover to cover.

Each iteration of the Guidebook reflects the aggregate knowledge gained by your efforts. Thank you! Feel free to use the comments section below for suggestions and questions.