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)

One thought on “Help Wanted: Identifying conditions that can complicate retrofits

  1. Graham,

    Thank you for this simple but eye-opening exercise. You identify a number of nearly universal conditions on single-family homes, and point out how the concept of industrialized retrofits poses many (some minor, some major) technical difficulties. In many cases a panelized approach would not make sense, and one would look to other measures (air-sealing, adding insulation, swapping mechanicals, adding solar panels) to achieve a de-carbonized home. Otherwise, the good old-fashioned “chainsaw retrofit” utilizing offsite-built panels would be the more comprehensive approach. Whether it made financial, resiliency, or carbon sense to do so will take a larger exercise to determine.

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