Sheet A-1 · Altadena, California
Ground-up homes. Tear-downs. Rebuilds. Altadena.
An independent guide to designing, permitting, and building a custom home in unincorporated Altadena — from hillside lots above the wash to flat streets off Lake, written in plain language.
CSLB #1103479Featured builderAltadena, CA 91001
02 — Scope of work
What we cover
Hillside & Slope-Lot Home Building in Altadena
Building a house on a slope in Altadena? Get clear sloped lot construction costs, caisson foundations & hillside expertise—no budget surprises. Call today!
Build on Your Lot in Altadena
Ground-up custom homes & wildfire rebuilds in Altadena. Learn costs, permits, contractor vetting & site prep from lot assessment to move-in. Get your guide!
Tear-Down & Rebuild in Altadena
Compare remodel vs tear down in Altadena: costs, wildfire rebuild timelines, permits, and debris removal. Start your like-for-like rebuild with a local expert t
Custom Home Builder in Altadena
Planning a ground-up build or Eaton Fire rebuild in Altadena? Get clear answers on cost, permits & timelines from a licensed custom home builder. Call today!
Eaton Fire Rebuild Guide: Altadena
Navigate Eaton Fire rebuild permits, Chapter 7A codes, and costs with a trusted Altadena fire rebuild contractor. Start your recovery—get the guide today.
03 — Estimating
What custom construction costs in Altadena
$450–$900+per sq ft · high-end custom · 2026
Site work & foundations
Flat lots vs. cut-and-fill pads, retaining walls, and getting water, power, and sewer to the street.
Design & engineering fees
Architect, structural engineer, soils report, and Title 24 energy calcs — typically a separate line from construction.
Finish level
Builder-grade to architect-grade: windows, cabinets, stone, and mechanical systems move the number more than square footage does.
Hillside grading
Sloped lots add engineered retaining, drainage, and access costs — Altadena's foothill terrain is the biggest single variable.
Ranges, never promises — your plans and the county process decide.
04 — Rebuild
Rebuilding after the Eaton Fire
If the fire took your Altadena home, the path back runs through a sequence: insurance decisions, design under wildfire code, county permits, then construction. Here is that sequence, step by step.
Insurance & decisions
Document everything, understand your settlement options, and decide whether to rebuild, sell the lot, or wait — before design money is spent.
Design & WUI code basics
New plans must meet current Wildland-Urban Interface fire code: ember-resistant vents, ignition-resistant materials, defensible space.
LA County permits
Unincorporated Altadena permits through LA County Public Works and Fire; requirements vary by lot, hazard zone, and hillside status.
Build
A licensed general contractor carries the permit set through construction, inspections, and final occupancy.
Official county resources: recovery.lacounty.gov
05 — Featured builder
JMB Builders LLC
A licensed general building contractor building custom homes in Altadena and the San Gabriel foothills.
Featured placement — disclosed.
- License
- CSLB #1103479
- Classification
- B — General Building
- Status
- Current & active · expires 04/30/2027
- Bonds
- $25K + $100K bonds on file
- Insurance
- $2M liability
07 — Site plan
Own a lot in Altadena? Start with a conversation, not a contract.
Talk through the lot, the slope, and what you want to build — before anyone asks you to sign anything.