The Culture of the Luiseño Indians, by Philip Stedman Sparkman, , at sacred-texts.com
The primitive house was of a conical form. A circular pit was dug in the earth, perhaps two feet deep. Some crotched poles were then set in the ground with the tops placed together, no king-pole being used. Other smaller poles were then leaned against these and the whole covered with brush so as to shed the rain. An opening was left at one side as an entrance. There
was also an opening left at the top for the smoke to escape. When the weather was fine, cooking was performed out of doors; at other times a fire was built in the center of the house. During cool nights a fire was also built in the center, and around this the inmates slept, with their feet towards it. A house built partly underground in this manner requires but little fire to warm it. Sometimes the entrance was through a covered way extending some distance, through which one crawled on hands and knees to enter. In the mountains the poles of the house were covered with cedar bark instead of brush, and on the coast large rushes or sedges were used to cover the pole framework. Often the house was built without any pit, especially if it was only intended for temporary or casual use.
Costanso, in his report of the expedition of 1769, speaks of the Indians of San Diego as living in "shelters of boughs and huts of a pyramidal shape covered with earth," and of those of the Santa Barbara channel as having houses "of a spherical form in the fashion of a half orange, covered with rushes, with the hearth in the middle, and in the top of the house a vent or chimney to give exit for the smoke." As the former of these people lived south and the latter north of the Luiseño and other Shoshonean tribes, much the same style of dwelling seems to have prevailed all along the coast slope of Southern California.