Residential Structural Drawings

I need detailed structural engineer drawings for a residential project. Existing architectural plans are available.

Key requirements:
- Roofing support structures (for dormer)
- Chimney breast support (to replace gallows brackets)

Ideal skills and experience:
- Expertise in residential structural engineering
- Familiarity with interpreting and working from existing architectural plans
- Experienced with building regulations for England
- Proficiency in roofing and chimney support design

Please provide samples of previous work and a timeline for completion.