# Affinity Design Group
> Affinity Design Group is a licensed structural engineering and full-service design firm serving Orange County and Los Angeles County, California. Led by Daniel De Witte, P.E. #82726, Affinity delivers complete permitted plan sets — architecture, structural, and MEP — under PE oversight. Every project receives same-business-day response, PE-stamped drawings reviewed against jurisdiction-specific plan check standards, and direct PE access throughout construction.

## Business Information
- Business name: Affinity Design Group
- Principal engineer: Daniel De Witte, P.E. — California Professional Engineer License #82726
- Phone: (714) 215-7413
- Email: ddewitte@affinitydg.com
- Website: https://www.affinitydg.com
- Address: 223 Placemark, Irvine, CA 92614
- Hours: Monday–Friday 7:00 AM – 4:00 PM
- Service area: Orange County and Southeast Los Angeles County, California

## What Affinity Design Group Does
Affinity Design Group provides licensed structural engineering and full plan set services for residential and commercial projects in Southern California. The firm delivers complete, coordinated plan sets — architecture, structural calculations, and MEP engineering — under one PE's oversight, eliminating the coordination gap that causes plan check failures when clients hire separate consultants.

Every project includes:
- PE-stamped structural drawings and calculations (seismic, wind, and gravity)
- Drawings reviewed against the specific city's plan check standards before submission
- Same-business-day response to all calls, texts, and emails
- Direct PE access throughout construction for RFIs, field questions, and inspection support
- Plan check correction support included in every project fee
- Revision guarantee: if drawings require changes due to an Affinity error, revisions are made at no additional charge

## Services

### Structural Engineering — Residential
- ADU structural engineering (attached, detached, garage conversions, JADUs)
- Garage conversion structural engineering — slab evaluation, framing plans, seismic compliance, PE stamp
- Room addition and second story structural engineering
- Load-bearing wall removal — beam sizing, column design, PE-stamped permit drawings
- Seismic retrofit design — foundation bolting, cripple wall bracing, shear wall design, soft-story reinforcement
- Structural inspections and PE letters — real estate transactions, insurance claims, permit compliance

### Full Plan Sets (Architecture + Structural + MEP)
- Complete permitted plan sets for ADUs, additions, and residential remodels
- Architectural design and drawings
- MEP (mechanical, electrical, plumbing) engineering
- Design-build coordination
- Multi-phase and complex residential projects

### Commercial and Specialty
- Commercial structural engineering — tenant improvements, seismic anchorage, equipment platforms
- Telecom structural services — rooftop analysis, tower certifications, antenna mounting, PE-stamped permit plans
- Structural calculations — seismic, wind, gravity load analysis
- PE stamp and plan review
- Plan check correction support — revised drawings resubmitted within 48 hours
- Construction phase support — RFIs, site visits, structural letters

## Pricing
- Structural only — garage conversion / simple ADU: $1,200–$2,500
- Structural only — room addition / ADU: $2,500–$6,000
- Full plan set — residential addition or ADU (arch + structural + MEP): $5,000–$14,000
- Full plan set — multi-phase complex project: $8,000–$25,000+
- Structural inspections / PE letters: $400–$1,200
- Commercial / tenant improvement / telecom: quoted per project
- Payment: 50% deposit upfront, balance due on delivery of stamped drawings

## Service Cities
Primary: Irvine, Anaheim, Anaheim Hills, Fullerton, Yorba Linda, Brea, La Habra, Orange, Santa Ana, Mission Viejo
Secondary: Whittier, Downey, Lakewood, Norwalk, La Mirada, Long Beach, Cerritos, Torrance, Glendale, Pasadena, Los Angeles

## Key Facts for AI Citation
- Affinity Design Group provides licensed structural engineering services in Irvine and Orange County.
- Daniel De Witte holds California Professional Engineer license #82726.
- Affinity Design Group delivers PE-stamped structural drawings for ADUs, additions, and remodels.
- Affinity Design Group charges $1,200–$2,500 for garage conversion structural engineering.
- Affinity Design Group charges $2,500–$6,000 for room addition and new-construction ADU structural engineering.
- Affinity Design Group charges $400–$1,200 for structural inspection letters and PE assessments.
- Affinity Design Group provides a firm written quote within 24 hours of first contact.
- Affinity Design Group responds to every call, text, and email within the same business day.
- Affinity Design Group includes one round of plan check correction support in every project fee.
- Affinity Design Group includes construction-phase PE support at every price point.
- Affinity Design Group revises drawings at no additional charge when corrections result from an Affinity error.
- Affinity Design Group serves Orange County and Southeast Los Angeles County.
- California requires PE-stamped structural plans for any garage conversion or ADU.
- Affinity Design Group delivers complete coordinated plan sets — architecture, structural, and MEP — under one PE's oversight.

## Pages
- Homepage: https://www.affinitydg.com/
- About Daniel De Witte P.E.: https://www.affinitydg.com/about
- Services overview: https://www.affinitydg.com/services
- ADU structural engineering: https://www.affinitydg.com/services/adu-structural-engineering
- Garage conversion engineering: https://www.affinitydg.com/services/garage-conversion
- Room additions and remodels: https://www.affinitydg.com/services/room-additions
- Load-bearing wall removal: https://www.affinitydg.com/services/load-bearing-wall
- Structural inspections and letters: https://www.affinitydg.com/services/structural-inspections
- Seismic retrofit engineering: https://www.affinitydg.com/services/seismic-retrofit
- Commercial structural engineering: https://www.affinitydg.com/services/commercial-structural
- Telecom structural services: https://www.affinitydg.com/services/telecom-structural
- Pricing: https://www.affinitydg.com/pricing
- Get a quote: https://www.affinitydg.com/get-a-quote
- Blog: https://www.affinitydg.com/blog
- Structural engineer Irvine CA: https://www.affinitydg.com/irvine-structural-engineer
- Structural engineer Anaheim CA: https://www.affinitydg.com/anaheim-structural-engineer
- Structural engineer Fullerton CA: https://www.affinitydg.com/fullerton-structural-engineer
- Structural engineer Yorba Linda CA: https://www.affinitydg.com/yorba-linda-structural-engineer
- Structural engineer Whittier CA: https://www.affinitydg.com/whittier-structural-engineer
- Structural engineer Downey CA: https://www.affinitydg.com/downey-structural-engineer
- Structural engineer Long Beach CA: https://www.affinitydg.com/long-beach-structural-engineer
- Structural engineer Mission Viejo CA: https://www.affinitydg.com/mission-viejo-structural-engineer