I'm very interested in these type of homes.
What you've featured is quite impressive. Thanks- Sharon

Most of them are cement-stuccoed; there's a good amount of evidence of failure and patching over the years. One had some unrepaired delaminated stucco sections; the adobes were exceptionally uniform and smooth-faced, as though they were made in a block press. That observation was also made by Pieper. All the mortar looked like it had been flushed, which may be an ongoing contributor to delamination problems (besides the fact that cement stucco just isn't a particularly good choice to use over adobe, particularly where the climate doesn't supply an almost ridiculously excellent drying regime).

The two oldest structures, per Pieper's research, are shuttered cob rather than adobe. We verified that with one of the owners, who let us poke around the place inside and out, top to bottom. In the basement above the windows, the bottom of the wall seemed to have a very high straw content. However, the owner had taken out a section of wall (after a poorly-executed excavation under a foundation caused it to sag) and piled the material out in the yard; there was very little straw in it.

Frankly, I was surprised that everyone we were able to speak with said that the houses' winter performance was good. One did say that the walls would start to feel chilly during prolonged cold snaps. None of them had compared their winter fuel use with their wood-framed neighbors, but they were satisfied that nothing was out of kilter in that regard. They were all quick to suggest that newer, tighter houses would certainly require less winter heating. All of the houses had old, single-pane windows and the leaky, uninsulated details that most houses of the era have. My wife, Sarah, pointed out that the adobe houses almost certainly would have outperformed their stick-framed contemporaries, which were uninsulated and drafty. Made sense; I kind of kicked myself for not realizing it on my own.

I'm still looking for good thermal modeling to find out how much mass and heat input would be required for an earthen house to perform to contemporary expectations in prolonged-cold climates with little insolation and no insulation. Until then, I'll have to continue to recommend insulated mass for that kind of situation.

The two last photos in that series, both in Bath NY, were for sale - the lovely pink and green Italianate for $100,000.