Multi-Family Mechanical Design

I need a comprehensive mechanical design for a multi-family, multi-story building. The design should include HVAC and plumbing systems.

Key Requirements:
- Design for HVAC and plumbing systems
- Suitable for multi-family, multi-story buildings
- Must comply with local building codes and regulations
- Energy efficiency and sustainability considerations are a plus

Ideal Skills and Experience:
- Proven experience in mechanical design for multi-family residential buildings
- Strong knowledge of HVAC and plumbing systems
- Familiarity with building codes and regulations
- Certification in mechanical engineering or related fields

Please provide samples of previous work and relevant certifications.