Beam Calculation for Window Enlargement

I need a structural engineer to provide a beam calculation for enlarging a window opening. The property is a bungalow with a loft conversion. We already have building regulations in place.

Requirements:
- Steel beam calculation
- Span of 3 to 6 meters
- Support for floor and roof load

Ideal Skills and Experience:
- Structural engineering expertise
- Experience with residential projects
- Knowledge of building regulations and compliance