Planning to Rebuild — Altadena & Pacific Palisades
Parcel-level rebuild scenarios after the January 2025 Eaton & Palisades fires
Why this study
The Eaton and Palisades fires tore through neighborhoods shaped by history and community, but also by zoning. Zoning and land-use decisions by state and local governments will continue to shape how Los Angeles rebuilds. The instinct to rebuild these areas exactly as before risks repeating past planning mistakes and may deepen the region's housing affordability crisis. This study asks how different zoning scenarios could guide rebuilding while balancing local and regional housing needs.
The question
For every parcel: how much housing existed, how much could legally be rebuilt, and how much is actually being rebuilt? Each parcel carries four numbers:
How Scenario 2 is computed
R1, RE*, RA, A1, R-1, R-A → 1 unit per lot
lot area ÷ sq-ft-per-unit (RD1.5 = 1,500 sf/du …)
max density × acres (R-3 = 20 du/ac), envelope fallback
rebuilt via CUP → R-3 density proxy
• In single-family zones, zoning allows one home per lot no matter the lot size, so capacity is simply 1. Over 95% of residential parcels in both areas fall here.
• LA City multifamily zones set a minimum lot area per dwelling unit, so capacity = lot size ÷ that number. Example: a 6,000 sq ft lot in RD1.5 (1,500 sq ft per unit) → 4 units.
• LA County multifamily zones instead cap density in units per acre, so capacity = density × acreage (a half-acre R-3 lot at 20 du/ac → 10 units). Where Title 22 lists no density, we estimate how many units fit in the allowed building envelope (height, coverage, setbacks).
• Apartments already standing on commercial zones are not allowed by right, but can rebuild with a conditional use permit; we credit them at R-3-equivalent density.
State ADU allowances are not part of Scenario 2's parcel numbers; they appear separately as the dark segment of bar 2 in the chart below (one potential ADU per eligible single-family lot).
Key findings (draft)
On destroyed, by-right-residential parcels:
• Pacific Palisades: 5,332 pre-fire units vs 5,172 allowed by zoning today.
• Altadena: 6,520 pre-fire vs 6,405 allowed.
• Both areas hold legal nonconforming multifamily: older duplexes and apartments that current zoning would not permit at the same density.
• State ADU law is the main capacity lever: ADUs are 19% of the units permitted so far in the Palisades and 30% in Altadena.
Scenarios at a glance
Destroyed by-right parcels · permits as of Sept 29, 2026 (Palisades: issued; Altadena: issued or later) · hatched bars are 5-year projections · bar 3 is a draft; the dashed line on it is the 1.25 × target.
Reading the chart
Zoning alone offers almost no headroom. On the destroyed by-right parcels, base zoning allows 5,172 units in Pacific Palisades and 6,405 in Altadena, slightly fewer than existed before the fires. Nearly all of the upside in bar 2 comes from state ADU law, which adds one potential unit on each single-family lot (+3,926 Palisades, +5,378 Altadena).
Scenario 3 starts from a target. The target is 1.25 times the pre-fire housing: 6,700 units in Pacific Palisades and 8,200 in Altadena. The wildland buffer takes in 601 destroyed single-family lots in the Palisades and 146 in Altadena, and those get no new ADU. The corridors hold 1,191 and 1,641 units. Outside the buffer we assume ADUs at the current adoption rate: 20% of the single-family lots with a home permit in the Palisades also add an ADU or JADU, and 31% in Altadena. That brings Scenario 3 to 6,817 units in the Palisades (1.28 times pre-fire) and 9,476 in Altadena (1.45 times). At a 10% ADU share the totals are 6,477 and 8,367.
Multifamily is rebuilding slowest. Twenty months after the fires, Palisades permits cover just 40 multifamily units of the 1,339 destroyed; Altadena covers 99 of 1,056. Insurance gaps, condo and HOA coordination, and financing make apartment rebuilds slower and less certain than single-family homes, and these units were the lowest-cost housing in both neighborhoods.
The five-year projection lands below pre-fire housing. Assuming 85% of destroyed single-family parcels rebuild, 65% of multifamily units return, and ADU adoption continues at observed rates, the two areas recover to roughly 92% (4,907 of 5,332) and 98% (6,376 of 6,520) of their pre-fire housing. On the current trajectory the fires leave the region with less housing than before, which is the motivation for Scenario 3.
Takeaways
• ADUs can add housing without rezoning: 20% of the single-family lots with a home permit in the Palisades also add an ADU or JADU, and 31% in Altadena.
• Rebuilding “like for like” may disadvantage people who lost homes, particularly the underinsured, whose best path to compensation may be selling to a developer.
• The current rebuilding trajectory will not move the region closer to its housing targets.
• At the same time, zoning and state housing law are not generally aligned with fire-safety best practices; this is the tension Scenario 3 takes up.
Not in this draft
• SB 9 excluded by design. Uptake is minimal (owner-occupancy requirement deters lot-splitters; hillside carve-outs limit Palisades). The theoretical SB 9 ceiling (4 units × every destroyed single-family lot ≈ 15,700 Palisades / 21,500 Altadena) is reported only as this footnote; it is not a feasible outcome. Density bonus also not modeled. Events since mid-2025 reinforce this exclusion: a July 2025 executive order let fire-affected jurisdictions suspend SB 9 in rebuild areas, Los Angeles blocked SB 9 lot splits in the Palisades, Pasadena repealed its SB 9 ordinance (July 2026), and the pending SB 1090 (Pérez) would bar SB 9 projects across Altadena. A YIMBY Law lawsuit is challenging the suspensions, so the legal ground remains unsettled either way.
• Palisades permit data is issued-only (LA City open data); Altadena includes the full application pipeline (EPIC-LA), so progress views are not strictly comparable across the two areas.
• SCAG's ADU-eligibility model under-predicts for LA City parcels (detached-only assumptions).
• Parcel inventory is DINS-inspected parcels, not every parcel in the fire perimeter.
How to use the map
• Pick a question under Map views.
• Click any parcel for its scenarios and zoning standards.
• Filters narrow to destroyed parcels, one fire area, or the by-right slice; legend counts update live.
• The solid dark line is the official fire perimeter (NIFC/CAL FIRE). The dashed line is the extent of destroyed parcels, which is much smaller since the perimeter includes unburned wildland.
Data sources
Cal Fire DINS damage inspections · NIFC WFIGS interagency fire perimeters · LA County Assessor parcels · LA City Planning & LA County DRP zoning · zoning standards extracted from LAMC & Title 22 · LADBS permits (LA City / Palisades, checked Sept 29, 2026) · LA County EPIC-LA case history (Altadena, checked Sept 29, 2026) · California Protected Areas Database 2026a · OpenStreetMap street lines · Census TIGERweb city/county boundaries · CAL FIRE Fire Hazard Severity Zones (SRA 2007 / LRA 2011) · SCAG Annual Land Use 2020 (HELPR v3: ADU eligibility, slope, WUI, FHSZ).
UCLA OAG Wildfire Research: Lens / Nelms. Working draft; numbers subject to revision.