01 — Why It Matters
SB 9 turns what was a multi-year planning ordeal into a permit pathway homeowners can actually follow — addressing California's housing shortage by streamlining lot splits and multi-unit infill.
Structural Engineering · SB 9 Lot Splits · California
Complete structural plans for SB 9 lot splits and up to four-unit single-family infill — permit-ready, code-compliant, no public hearings.
Senate Bill 9 (SB 9) is a California law designed to increase housing density by allowing homeowners in single-family zones to split their lots and create up to two primary residential units on each parcel. This effectively enables up to four homes where previously only one was allowed, without discretionary review or public hearings.
SB 9 turns what was a multi-year planning ordeal into a permit pathway homeowners can actually follow — addressing California's housing shortage by streamlining lot splits and multi-unit infill.
Sigma Structural Inc. provides complete structural engineering plans and calculations for SB 9 projects throughout Southern California, fully compliant with current building codes and SB 9 requirements.
Confident navigation of the technical aspects of lot splits and multi-unit construction — supporting efficient permit approvals and timely construction starts.
Real reviews from architects, contractors, and homeowners we've worked with across Southern California. Read every word our clients have shared on Google about partnering with Sigma Structural Inc.
