With the increasing price of lumber and construction materials in the U.S., 3D-printed houses become a more viable way of building houses. Designing the foundations of mini-houses isn't difficult. However the foundation of a full-size house is different; the larger the more difficult. The one piece nature of a 3D-printed house makes it almost impossible to repair if the foundation shifts. Foundation repair is the largest home maintenance cost of existing houses. Thus, the designs of most existing house foundations are not adequate.
Usually the form for the foundation is printed, rebar is placed in the form, and the foundation poured. Piers seem to be a most. While shims can be added or altered on piers with pier and beam, unless the beams hold the house ridge (minimum flexing), this doesn't appear to be an option. What are adequate designs for 3D printed houses?
Family dwellings in the U.S. usually run from 1,100 to 3000 sq.ft. (aprox. 100 to 280 sq.meters). More common is 1500 to 2000 sq.ft. (aprox. 140 to 190 sq.meters). Ceilings are at least 8 ft. (2.44 meters) high.
We can speculate, but a good answer would reference actual construction. Some speculation:
Print individual wall panels on a bed flat on the ground similar to how warehouses are constructed out of wall panels. Thus, eliminate the one piece.
One could make concrete pier and beams in a grid pattern within the slap. The beams would need to be ridged enough to keep the house from flexing.
Structures built as transportable units would survive a shifting foundation and thus be reparable.
China 3D-prints apartments. Their techniques may give insight into how to design house foundations for 3D printing.
A 380 sq. meters (4000 sq.ft.) building is being printed in Germany, but the webpage gives no description of the foundation: https://www.designboom.com/architecture/first-3d-printed-apartment-building-germany-construction-peri-cobod-11-24-2020/
A huge foundation issue is clay soil in a climate that has both wet and dry seasons.
P.S. The wise customer will want this answered before purchasing. The construction company would want this answered to prevent a class action lawsuit. The industry would want this answered to avoid a setback in consumer confidence.