Is a Geotechnical Investigation Worth It for Your San Diego ADU? 2025 Cost, Benefits & Verdict
A geotechnical investigation is worth the cost if your Accessory Dwelling Unit (ADU) sits on a hillside lot, in a mapped liquefaction zone, near an Alquist-Priolo Earthquake Fault Zoning Act fault, or on expansive soils. If your parcel is flat, has documented stable soils, and falls outside a geologic hazard zone overlay, several San Diego…