The X-100 is an experimental steel house designed by A. Quincy Jones with his partner Frederick Emmons for Eichler Homes and built in 1956 at the San Mateo Highlands development in California.

Eichler Homes was founded as a developer of tracts of single-family houses in the Bay Area suburbs during the California building boom that followed World War II.

[4] Jones had also designed a steel-frame house for the "Research Village" project sponsored by U.S. Gypsum in Barrington, Illinois, and another in 1954 as his personal residence in Crestwood Hills, Los Angeles (destroyed in the 1961 Bel Air Fire).

[5][6][7] Eichler commissioned the X-100 from Jones in 1955, with two aims: further exploration of the practicality of steel for future homes, also showcasing advanced household appliances, some of them prototypes; and promotion of the San Mateo Highlands development, whose location was at the time remote from highways.

[11] The house structure was pre-fabricated, with advice from Pierre Koenig, like Soriano a Los Angeles architect with considerable experience building in steel.

[9][14] Modern and prototype equipment in addition to the underfloor heating (standard in Eichler houses) included a black dishwasher said to incorporate five years of research,[8] a "pulverator" (garbage disposal), a double oven with "vari-speed control" and attached to a liquor storage cabinet, a refrigerator-freezer, a washer-dryer, a water heater, a radio and intercom over the kitchen counter,[14] a built-in five-function blender, and a two-burner cooktop for warming food between the two sliding sections of the built-in dining table.

[13] Originally the house had a rotating fireplace in the entry garden[13] and interior decor by Knorr and Associates, furniture by Herman Miller, and accessories by Gump's.

[13] On display for three months as the "house of tomorrow", the X-100 was visited by 150,000 people,[9][13] written about in publications including Popular Science, Life, Sunset,[13] Arts & Architecture, and Living for Young Homemakers,[8] and covered in a newsreel.