Hillside & Slope Engineering Services
Specialized structural engineering for hillside home construction, slope stability solutions, and foundation systems for challenging terrain. Our licensed engineers design safe, buildable structures on California hillsides with expertise in caisson foundations, retaining systems, and geotechnical coordination.
What is Hillside Engineering?
Hillside construction in California presents unique structural engineering challenges that demand specialized expertise. Steep slopes, variable soil conditions, seismic forces, drainage complexities, and environmental regulations all converge to make hillside projects among the most technically demanding in residential and commercial construction. Our structural engineers have extensive experience designing buildings on slopes, working closely with geotechnical engineers, architects, and contractors to deliver safe, cost-effective hillside structures. We specialize in deep foundation systems, retaining structures, and structural framing that accounts for the complex load paths inherent in hillside construction.
Why Choose Our Hillside Engineering Services
Deep foundation expertise including caissons, grade beams, and piers
Close coordination with geotechnical engineers for site-specific solutions
Retaining wall and shoring design integrated with building structures
Seismic design for hillside structures with irregular configurations
Slope stability awareness informing all structural design decisions
Experience with California Coastal Commission and hillside ordinance requirements
Value engineering to control costs on inherently expensive hillside projects
What We Provide
Comprehensive hillside engineering services with complete documentation
Hillside Foundation Design
Engineering of deep foundation systems for hillside construction including drilled caissons (piers), grade beams, micro-piles, and combinations designed to transfer building loads through unstable surface soils to competent bearing material below.
Retaining System Engineering
Design of retaining walls, soldier pile walls, tie-back anchored walls, and soil nail walls required for hillside grading, building pad creation, and slope stabilization on residential and commercial hillside projects.
Hillside Structural Framing
Design of structural framing systems for buildings on slopes including stepped foundations, cantilever framing over slopes, multi-level stepped structures, and lateral force-resisting systems for irregular hillside configurations.
Slope Stability Coordination
Integration of geotechnical slope stability analysis into structural design decisions including setbacks from slope faces, foundation depth requirements, surcharge load limitations, and drainage provisions.
Shoring & Excavation Support
Temporary shoring design for hillside excavation including soldier pile and lagging, sheet pile walls, and braced excavations required to safely construct hillside foundations and retaining walls.
Geotechnical Coordination
Close coordination with geotechnical engineers throughout design including review of boring logs, interpretation of soil parameters, foundation recommendations, and construction monitoring requirements.
How It Works
Our streamlined process for hillside engineering
Site Reconnaissance
Visit the hillside site to assess slope conditions, access constraints, existing improvements, drainage patterns, and any visible signs of slope movement or instability.
Geotechnical Review
Thorough review of the geotechnical investigation report including boring logs, soil strength parameters, slope stability analysis, foundation recommendations, and grading requirements.
Foundation Strategy
Develop the foundation approach based on geotechnical recommendations, building loads, and slope geometry. Select caisson depths, sizes, and layout to efficiently support the structure.
Retaining Wall Design
Design all retaining structures required for the project including upslope and downslope walls, building basement walls, and any temporary shoring needed for construction.
Structural Framing Design
Engineer the building structural system accounting for complex hillside load paths, stepped floor elevations, cantilevered elements, and lateral force resistance for the irregular configuration.
Construction Documents
Produce comprehensive structural drawings including caisson schedules, grade beam plans, retaining wall details, framing plans, and all connection details for permit and construction.
Permit Processing
Navigate hillside permit requirements including geotechnical review boards, coastal commission approvals if applicable, and building department plan check with response to corrections.
Construction Administration
Site visits during critical construction phases including caisson drilling observation, reinforcement inspection, shoring installation, and structural framing verification on the challenging hillside site.
Common Applications
We provide hillside engineering for a wide range of projects
Cost Information
Transparent pricing for your project
Typical Range:
$5,000 - $20,000+ for structural engineering depending on project scope and slope complexity
Factors Affecting Cost:
- Slope steepness and building pad size
- Foundation type and depth (caisson depths significantly affect cost)
- Extent of retaining walls required
- Building size and number of levels
- Geotechnical complexity and soil conditions
- Shoring and temporary support requirements
Hillside structural engineering costs are higher than flat-site projects due to the specialized foundation systems and retaining structures required.
Timeline
What to expect for your project
Design Phase
3-6 weeks for structural design
Permitting
4-10 weeks depending on jurisdiction and hillside review requirements
Total Timeline
7-16 weeks from start to permit; hillside ordinance reviews may extend timeline
Timelines vary based on project complexity, jurisdiction requirements, and information availability. We provide detailed schedules during consultation.
Frequently Asked Questions
Common questions about hillside engineering
Can you build on a steep hillside in California?
Yes, construction on steep hillsides is achievable with proper engineering. California has thousands of hillside homes built on slopes of 30% to over 100% grade. The key requirements are a thorough geotechnical investigation, appropriate deep foundation systems (typically caissons), engineered retaining structures, and structural framing designed for the complex hillside load paths. Costs are higher than flat-site construction, but the views and property values often justify the investment.
What type of foundation is used for hillside homes?
Hillside homes typically use drilled caisson (pier) foundations connected by grade beams. Caissons are drilled deep into competent bedrock or stable soil below the slope surface, providing a solid foundation that is not affected by surface soil movement. Caisson diameters typically range from 18 to 36 inches with depths from 10 to 40+ feet depending on soil conditions. The grade beam system ties the caissons together and supports the building above.
How much does hillside structural engineering cost?
Hillside structural engineering typically ranges from $5,000-$10,000 for smaller projects like additions or retaining walls, and $10,000-$20,000+ for new hillside home construction. The higher cost reflects the complexity of deep foundation design, retaining wall engineering, and the specialized analysis required for irregular hillside structures. These engineering fees represent a small fraction of the overall hillside construction cost.
Do I need a geotechnical report for hillside construction?
A geotechnical investigation is essential and required by all California jurisdictions for hillside construction. The geotechnical report provides critical information including soil and rock conditions at depth, slope stability analysis, foundation recommendations, grading guidelines, and drainage requirements. Without this information, structural design cannot proceed. We coordinate closely with geotechnical engineers and can recommend qualified firms.
What is a caisson foundation?
A caisson (also called a drilled pier or drilled shaft) is a deep foundation element created by drilling a hole into the ground and filling it with reinforced concrete. For hillside construction, caissons extend through unstable surface soils to reach competent bedrock or firm bearing material below. They resist both vertical building loads and lateral forces from soil movement. Caissons are the standard foundation solution for California hillside homes.
How do you handle drainage on hillside projects?
Proper drainage is critical on hillsides because water infiltration destabilizes slopes and increases lateral loads on retaining walls. We coordinate drainage design including surface grading to direct water away from the building, subdrains behind retaining walls, foundation drains, and connection to the storm drain system. All drainage provisions are integrated into our structural plans and coordinated with the geotechnical and civil engineers.
What is a hillside ordinance?
Many California cities have hillside development ordinances that impose additional requirements on construction in steep terrain. These ordinances typically limit grading, restrict building height and mass relative to the slope, require geological and geotechnical reviews, mandate specific drainage and erosion control measures, and require additional design review. We navigate these requirements as part of our hillside engineering services.
How long does hillside engineering and permitting take?
Structural design takes 3-6 weeks for most hillside projects. Permitting takes 4-10 weeks depending on the jurisdiction and any special review requirements such as hillside ordinance review, geological review, or coastal commission approval. Total timeline from start to permit is typically 7-16 weeks. Complex projects with multiple review agencies take longer. We establish realistic timelines at the start of each project.