A small, self-contained apartment attached to the main house. The bedroom was comfortable but would have been a bit tight for 2 adults. Extremely secluded and quiet location -- note that on some GPS, one of the roads is labeled "A Road", but there is actually a name for it (which Julia will give you as part of her instructions on getting to the house). The only "noise" that could be heard was the sound from her livestock.
Two pieces of advice:
(i) Check in during daylight hours and/or have a powerful flashlight with you. When I arrived, Julia was away and the entire driveway and house was so dark (almost pitch black) that I could not see the path to the apartment that Julia had told me to take -- it was not until the morning that I realized what she was referring to. In fact, I initially drove past the driveway without even realizing that there was a driveway too.
(ii) Try not to drive a large vehicle -- the driveway is pretty tight, and the allocated parking will probably not fit anything larger than a standard car.
Also, the temperature in many parts of Volcano and Volcano Village is at least 10 degrees cooler than that by the coast (down to the mid-high 50s, so one should dress accordingly).
Highly recommended.