European Home Systems Design

I need a detailed design for water supply, drainage, and HVAC systems for a 250 sqm house, compliant with European regulations.

Requirements:
- Water supply system design
- Drainage system design
- HVAC system design (energy efficiency preferred)

Ideal skills and experience:
- Expertise in European residential system design.
- Knowledge of HVAC systems with heat-pumps, and radiant floors.
- Understanding of local regulations and standards

Please provide a portfolio of similar jobs showing what type of documents you can provide.