0 Harness St, Spring Valley, California 91977

Rare double-lot opportunity in Spring Valley. Two contiguous parcels sold together — APNs 578-102-14-00 and 578-102-15-00 — combining to create a highly flexible development site in one of San Diego County’s most in-demand inland corridors. Under current 2026 California law, this site supports significant density. Build two single-family residences (up to approximately 3, 000 sqft each), with ADU and Junior ADU potential on each lot per California’s expanded ADU statutes. SB-9 lot-split and duplex provisions may unlock additional units, subject to County of San Diego zoning verification. Whether you are a builder looking for your next project, an investor positioning for long-term hold, or an end-user who wants to build custom and keep a second lot — this is the kind of opportunity that rarely comes packaged this cleanly. No demo. No teardown. Just raw land, ready to go. Buyer to verify all zoning, permitted uses, utility availability, and development potential with County of San Diego prior to close.