Design Engineer for Home Addition

I need a comprehensive design engineering plan for a 400-foot bedroom and bathroom addition to my home in San Lorenzo, California. The project requires:

Architectural Design:
- Creating detailed floor plans
- Developing elevation drawings

Structural Engineering: Assessing and ensuring the structural integrity of the addition.

Interior Design: Designing the interior layout and aesthetics.

Ideal skills and experience:
- Proven experience in residential design and engineering
- Strong portfolio with similar projects
- Knowledge of California building codes and regulations
- Good communication skills for collaboration

Please provide a detailed proposal with your experience and approach.