Which foundation is cheapest for a small house as the frost line gets deeper?

What it found

Sizes and prices four foundations for the house-framing house: slab on grade, frost-protected shallow, crawlspace and full basement, from roof and floor loads, soil bearing and frost depth. At 48 in frost the midpoint first costs are $13.2k (frost-protected shallow), $20.6k (slab), $24.1k (crawlspace) and $54.9k (basement); the frost-protected shallow foundation is cheapest in all 5,000 price draws from about 18 in of frost down, a basement adds $25–36 per sq ft over a crawlspace, and soil matters only below about 1,500 psf. Stylised: prices from memory, an invented insulation-wing rule, no soil-pressure, drainage or energy checks, and not a design.

A figure from its own output

Paper, code and results

• README and method
• Experiments and results
• Code
• Tests

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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.