- Typical cost
- Scoped after soils and structural engineering
- Typical timeline
- 10–24 months depending on scope and plan check
- Permits through
- LA County Building & Safety
- Service area
- Altadena, San Gabriel Valley
What We Build on Slopes
New hillside homes, additions and decks tied into existing hillside structures, plus the foundation and retaining work that holds them up.
- Caissons, grade beams and deepened footings
- Engineered retaining walls and shoring
- Hillside additions and cantilevered decks
- New view-lot custom homes
- Driveway, access and drainage work
Hillside Construction Conditions in Altadena
We do a lot of rebuild and repair work here, and the pattern is consistent: fire-hardened exteriors, upgraded defensible space, and a structure brought up to current code rather than restored as it was. Homes date largely from 1910 to 1950, so foundations are often unbolted, and slope and drainage matter on the upper streets closer to the mountains.
- Los Angeles County Building & Safety permits, not a city process
- Very High Fire Hazard Severity Zone materials and assemblies
- Fire rebuild and repair work brought fully up to current code
- 1910 to 1950 homes with unbolted foundations and original wiring
- Slope, drainage and brush clearance on foothill-adjacent streets
Soils and the Hillside Ordinance
Hillside parcels in LA fall under grading limits, height restrictions measured off natural grade, and haul-route rules for exported dirt. A geotechnical report drives the foundation design, and it's the first thing we order.
- Geotechnical and soils investigation
- Grading and export quantity limits
- Haul-route approvals where required
- Height and setback verification off natural grade
- Drainage and erosion control
Access Is Half the Cost
On a narrow canyon street, how material and equipment reach the site can matter as much as the design. We plan staging, craning and delivery sequencing early instead of discovering it mid-project.
- Site access and staging plan
- Crane and pump placement
- Neighbor notification and street use permits
- Sequenced deliveries to keep the street open
FREQUENTLY ASKED QUESTIONS
Do you do hillside construction in Altadena?
Yes. Altadena is part of our regular service area. We'll come out for a free on-site consultation, walk the property, and tell you what's realistic before you spend anything on design.
What does hillside construction cost in Altadena?
Scoped after soils and structural engineering. Site conditions in Altadena and your material selections move the number, which is why we price after walking the property rather than over the phone.
Who issues the permit in Altadena?
Permits for this work go through LA County Building & Safety. We handle the submittal, plan check corrections and inspections as part of the project.
How much more does hillside construction cost?
Deep foundations, retaining walls, grading and difficult access typically add a meaningful premium over a comparable flat-lot project. The soils report and engineering tell us how much, which is why we scope it after those come back.
Do I need a soils report?
For hillside work in Los Angeles, almost always. The geotechnical report specifies whether you need caissons, grade beams or deepened footings, and plan check will ask for it.
Can you add on to a house on a steep slope?
Yes. Hillside additions are common in Silver Lake, the Hollywood Hills, Sherman Oaks and Glendale. They need structural engineering to tie the new work into the existing structure and the slope below it.
Do you take hillside projects near me across the LA area?
Yes. We build on slopes throughout Los Angeles County and nearby counties within roughly 100 miles of Woodland Hills, from the Hollywood Hills and Silver Lake to Sherman Oaks, Glendale, Malibu and the Conejo Valley.
Similar Projects We've Built
DISCUSS YOUR PROJECT WITH 1 SMART BUILD
Licensed, bonded and insured design-build general contractor serving Los Angeles County and Southern California. Tell us about your property and goals, and we'll walk you through feasibility, permitting and a clear plan.