For most Wasatch Front valley homes, a full basement is the most common and usually the most cost-effective choice — providing 900–1,500+ sq ft of usable space at a modest cost premium over a crawl space, with excellent seismic performance from the massive concrete walls. Footings for any foundation type must reach frost depth regardless, so extending to full basement depth has relatively low marginal cost. Crawl spaces are appropriate where a high water table or shallow rock makes full excavation prohibitive. Slabs work for garages, ADUs, and additions — but require frost-protection edge insulation or thickened footings that many contractors miss. The right choice depends on site soils, topography, water table, and the homeowner’s goals for below-grade space. RainFire Builders presents all three options with Utah-specific cost and performance data before any foundation design is specified.