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Drainage
The critical consideration was water management. Digging below ground level created depression that would naturally accumulate water unless properly located and designed. The fatal error was building in location where groundwater was high or where surface water would drain into excavation.
Ideal sites were slopes or elevated areas where water would drain away naturally. Sandy or gravelly soils that drained well were preferred over clay soils that held water. The builder examined site after rain, looking for standing water or saturated soil—indicators of poor drainage that would create miserable living conditions.
Even with good site selection, deliberate drainage measures were necessary. Ditches around excavation perimeter intercepted surface water before it entered pit. Interior floor was either raised slightly above entry level (creating sump where water could collect and be removed) or sloped slightly toward exit so water drained out rather than pooling inside.
Soil Stability
The excavation walls needed to be stable—capable of standing without collapse, strong enough to support any above-ground structure. Sandy soils drained well but might not hold vertical walls. Clay soils were strong but could become saturated and unstable. Rocky soil was difficult to excavate but provided excellent stability.
The builder assessed soil by examining exposed banks, noting how well natural slopes held, observing whether similar excavations in area remained stable. This evaluation prevented investing labor in site that would ultimately fail due to unstable ground.
Sun Exposure
Orientation mattered for warmth and light. Siting pit-house on south-facing slope (in northern hemisphere) provided maximum sun exposure—warmth during cold months, light entering through doorway or smoke hole. North-facing sites remained colder, darker, less desirable unless other factors (proximity to resources, community location) outweighed solar disadvantage.
Wind exposure also influenced site selection. Protected locations—in tree groves, behind natural windbreaks, in terrain depressions—were preferred. Exposed sites required more substantial above-ground construction to resist wind damage.
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