Thoughts on ABCC Guidance Report on Residential Building Decarbonization

You might have seen this report on residential building decarbonization published by the Advanced Building Construction Collaborative (ABCC) earlier this year. Its purpose is to provide guidance to the building industry on doing “zero-carbon-aligned” buildings, both new construction and retrofit.

We at Phius had some input, but the report was mostly a U.S. Department of Energy effort. Here are a few remarks about how Phius’ programs relate to it. 

1. Their definition of zero-carbon-aligned is fine: “No on-site fossil fuel use, low power and thermal loads, obtains all energy from a carbon-neutral grid and/or carbon-neutral local resources currently or before 2050 under a planned scenario, and reduces impact on the grid through peak and general demand reduction and grid interactivity (or, alternatively, through off-grid operation), with the aim of a decarbonized US building stock before 2050.”

2. For new construction, Phius CORE and ZERO are two of only four voluntary certification programs recognized as having all the features they consider necessary (see Exhibit ES3). I’d say Phius is the “easy button” for zero-carbon-aligned new construction.

3. As for retrofits, our new REVIVE 2024 standard will also meet the definition of zero-carbon-aligned, but it will be more customized project-by-project compared to what the report talks about and what the retrofit decision tool that came out of it says. 

   1. I have previously suggested the idea of looking at a few discrete tiers of retrofit packages. In the interest of getting right to some prescriptive guidance, The ABCC really ran with that in its analysis, but to me that was always just a first step toward coming up with project-specific retrofit plans, and this is what is done in our new retrofit standard, REVIVE 2024. The report’s abstract says “The information in this report can serve as a springboard for further development and refinement of specific physical solutions” which is the approach REVIVE 2024 takes. Andreas Holm from FIW Munich talked about this approach in his PhiusCon 2022 keynote (1:58:02-1:59:02): “Every house is individual, and for every house – this is what the German government has decided – we need an individual retrofitting plan. And this will be mandatory. Every building needs an individual retrofitting plan, where an energy advisor goes there, inspects the house, and starts with a package of retrofitting, comes up with solutions and tells you: this is your current situation now, this is what you should do ASAP, in this year, in four years, later after you have more money. Every house needs a clear schedule what to do. And this is something we’re going to do.” 

   2. The retrofit decision criteria are also different in REVIVE 2024, which mainly uses resilience to grid outages to determine the upgrades. I hoped to have the resilience protocol ready to use in the analysis for this report, but instead the DOE came up with the rather elaborate logic described in Appendix C3. We do have some funding from the ABCC to overlay a resilience analysis onto the large set of simulation cases used to generate the retrofit part of the guidance report. Look for that later this year. REVIVE 2024 is also designed to deliver on the non-energy benefits of indoor air quality and durability versus hazardous events, which the report mentions in Appendix A2.  

Closing Thought

The ABCC report is looking for a decarbonized building stock by 2050. In that 2022 keynote cited above (1:56:00), Dr.-Ing. Holm told us that Germany had passed a climate law to decarbonize by 2045 and declared, “2045 starts now. There is no excuse that it's a long time to go. Everything we do now has an impact on 2045. There is no chance to replace something we are doing now by 2045. Every mistake we make now will have an impact on 2045 if we don't do it properly now…Everything you do now must be 2045 ready: you will not replace a window; we will not change the doors, you will not change the roof; you will not change the heating system by 2045 anymore because hopefully they will last 20 years or longer.”