Updated: February 2026
Commercial tenant improvement (TI) projects in Pasadena range from simple office reconfigurations to complete restaurant build-outs requiring extensive structural modifications. Whether you're a tenant preparing a new space, a landlord accommodating a tenant's needs, or a contractor bidding on TI work, understanding when and why structural engineering is required helps ensure smooth permitting and construction.
This comprehensive guide is part of our Commercial & Industrial Structural Engineering Guide and covers everything you need to know about tenant improvement structural engineering in Pasadena.
What Is Commercial Tenant Improvement Engineering?
Commercial tenant improvement structural engineering evaluates and designs structural modifications required when adapting an existing commercial space for a new use. TI structural engineers address:
- **New equipment loads** including HVAC, kitchen equipment, and special uses
- **Mezzanine and platform structures** for additional floor area
- **Storefront modifications** including new doors and windows
- **Roof penetrations** for exhaust fans and mechanical equipment
- **Floor reinforcement** for heavy storage or equipment
In Pasadena, tenant improvement projects must comply with:
- **California Building Code (CBC) 2025** - Structural requirements
- **Pasadena Municipal Code** - Local amendments
- **Historic preservation requirements** - For buildings in historic districts
- **Original building structural system** - Capacity limitations
**Pasadena Building Department Contact:**
- Phone: (626) 744-4200
- Address: 175 North Garfield Avenue, Pasadena, CA 91101
- Plan Check Turnaround: 3-4 weeks for TI projects
When Does a Tenant Improvement Require Structural Engineering?
Always Requires a Structural Engineer
**Load-Bearing Wall Modifications:**
- Removing load-bearing walls
- Creating openings in load-bearing walls
- Widening existing openings
- Adding headers and beams
**New Structural Elements:**
- Mezzanine or loft construction
- Rooftop equipment installation
- Heavy equipment foundations
- Canopy or awning attachments
**Change of Occupancy with Increased Loads:**
- Converting office to restaurant (kitchen equipment)
- Converting retail to gym (exercise equipment)
- Adding storage for heavy goods
- Installing industrial equipment
May Require Structural Engineering
**Depending on Scope:**
- Storefront modifications (removing mullions)
- New roof penetrations (size and location dependent)
- Suspended ceiling systems (if supporting significant loads)
- Signage attachments (size and mounting method)
Rarely Requires Structural Engineering
**Simple Improvements:**
- Non-load-bearing partition walls
- Cosmetic renovations
- Electrical and plumbing within existing structure
- HVAC ductwork within rated assemblies
What Types of Tenant Improvements Does AAA Engineering Support?
Office Build-Outs Structural engineering for:
- **Conference room additions** - Headers over new openings
- **Break room installations** - Equipment support
- **Server room infrastructure** - Raised floors and cooling
Restaurant and Food Service Specialized TI engineering for:
- **Hood and exhaust systems** - Roof penetrations and supports
- **Grease interceptor pits** - Floor modifications
- **Outdoor dining areas** - Patios and canopies
Retail Spaces Commercial retail TI including:
- **Interior partitions** - Dressing rooms and storage
- **Fixture mounting** - Heavy display systems
- **Signage structural support** - Blade signs and projecting signs
Medical and Dental Offices Healthcare TI engineering for:
- **Equipment installation** - Dental chairs, imaging equipment
- **Lab areas** - Fume hood support
- **Vibration control** - For sensitive equipment
Gym and Fitness Fitness facility TI including:
- **Floor reinforcement** - For dropped weights
- **Ceiling structure** - For hanging equipment
- **Vibration isolation** - Protecting adjacent tenants
What Is the TI Structural Engineering Process?
Step 1: Scope Assessment (1-2 Days) Initial project review:
- **Review architectural TI plans** - Understanding proposed changes
- **Review existing building documents** - Original structural drawings
- **Site visit** (if needed) - Existing conditions verification
- **Scope determination** - What structural work is required
- **Fee proposal** - Fixed-fee quote
Step 2: Structural Analysis (3-5 Days) Engineering evaluation:
- **Load calculations** - New equipment and occupancy loads
- **Modification design** - Headers, beams, reinforcement
- **Connection design** - To existing structure
Step 3: Construction Documents (5-7 Days) PE-stamped drawings:
- **Details** - Connection and reinforcement details
- **Calculations** - Supporting engineering backup
- **Coordination notes** - For other trades
Step 4: Permitting Support (2-4 Weeks) Pasadena permit assistance:
- Response to plan checker comments
- Phone consultations with plan check staff
Standard Project Timeline
- Engineering: 2 weeks
- Plan check: 2-3 weeks (can be concurrent with other disciplines)
How Much Does TI Structural Engineering Cost in Pasadena?
Fee Ranges by Project Type
| TI Type | Typical Scope | Engineering Fee | Timeline | |---------|--------------|-----------------|----------| | Office Renovation | 1-2 wall modifications | $3,000-$5,000 | 2 weeks | | Retail Build-Out | Storefront + walls | $5,000-$8,000 | 2-3 weeks | | Restaurant | Full kitchen, hood, cooler | $8,000-$15,000 | 3-4 weeks | | Medical Office | Equipment + modifications | $6,000-$12,000 | 3 weeks | | Gym/Fitness | Heavy loads + equipment | $8,000-$15,000 | 3-4 weeks | | Mezzanine | New structure | $12,000-$25,000 | 4-6 weeks |
Cost Factors TI engineering fees vary based on:
- **Number of structural modifications** - More changes = higher fee
- **Existing building documentation** - Missing drawings increase effort
- **Historic building status** - Additional requirements
- **Equipment complexity** - Heavy or unusual loads
- **Timeline requirements** - Rush fees for expedited service
Value of Professional Engineering
**Cost of NOT hiring an engineer:**
- Permit rejection and redesign: 4-8 weeks delay
- Change orders during construction: 10-20% cost increase
- Failed inspections: Project delays
- Potential unsafe conditions: Liability exposure
What Are Common TI Structural Challenges in Pasadena?
Historic Buildings Pasadena has many historic commercial buildings:
- **Ornate facades** - Preservation requirements
- **Original documentation** - Often unavailable
- **Historic district review** - Additional approval required
Older Construction Pre-1970s buildings often have:
- **Unknown conditions** - Requiring investigation
- **Non-standard framing** - Custom solutions needed
- **Lead and asbestos** - Coordination with abatement
Mixed-Use Buildings Buildings with residential above:
- **Fire separation** - Maintaining rated assemblies
- **Structural capacity** - May be limited
- **Construction hours** - Tenant coordination
Landlord Constraints Building owner requirements:
- **Insurance requirements** - Engineering documentation
- **Restoration obligations** - End of lease considerations
- **Building systems** - HVAC, electrical capacity
Why Choose AAA Engineering Design for Pasadena TI Projects?
Our Qualifications
**Experience:** 100+ TI projects annually **Specialty:** Fast-turnaround commercial modifications **Local Knowledge:** Extensive Pasadena Building Department experience **Response Time:** 2-week standard turnaround, rush available
Our Approach
- **Fast Turnaround** - Meeting lease commencement deadlines
- **Practical Solutions** - Minimizing construction costs
- **Permit Expertise** - Smooth plan check process
- **Responsive Service** - Quick answers during construction
Recent Pasadena Area Projects
- Medical office TI in East Colorado medical corridor
- Retail chain expansion in Paseo Colorado
- Creative office conversion in Playhouse District
Client Testimonials
How Do You Get Started with AAA Engineering Design?
Free Project Assessment Contact us to discuss your Pasadena TI project:
- Determination of structural requirements
- Fixed-fee quote
- Schedule to meet your timeline
Information to Provide For an efficient assessment, gather:
- Building address and suite number
- Proposed use/occupancy
- Any available existing building drawings
- Target permit date
Contact Information
**AAA Engineering Design**
- Phone: (949) 981-4448
- Email: info@aaaengineeringdesign.com
- Website: aaaengineeringdesign.com
- Service Area: Pasadena and all of Southern California
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Frequently Asked Questions
Do I need a structural engineer for a simple office renovation? If your renovation involves load-bearing wall modifications, new openings, or adding significant equipment loads, yes. If it's purely cosmetic with non-load-bearing partitions, probably not. We can advise with a quick review of your plans.
How do I know if a wall is load-bearing? Load-bearing walls typically run perpendicular to floor joists and align with walls or supports below. However, only a structural engineer can make the definitive determination by reviewing existing drawings or conducting a site investigation.
What information do you need to quote a TI project? At minimum, we need the architectural TI plans and building address. Helpful additional information includes existing building drawings, proposed use, equipment specifications, and target permit date.
Can you help expedite Pasadena plan check? While we cannot guarantee expedited city review, our thorough plans typically pass with minimal comments, avoiding delays from corrections. We also respond promptly to any plan check comments to keep the process moving.
Do you provide construction phase support for TI projects? Yes, we're available to answer contractor questions, review shop drawings, and address RFIs during construction. We can also provide site observation if required by the building department.
What happens if the existing building drawings aren't available? We can work with limited information but may need a site visit to verify existing conditions. In some cases, selective demolition may be required to confirm existing framing before finalizing design.
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*Need a tenant improvement structural engineer in Pasadena? Contact AAA Engineering Design at (949) 981-4448 for fast, professional TI structural design. Our PE-licensed team provides 2-week turnaround to meet your lease timelines.*