Structural Drawings & Calculations for Kitchen Extension

I'm looking for an experienced professional to produce comprehensive architectural and structural drawings, as well as necessary calculations, for a kitchen extension over a foul sewer. All work needs to comply with the regulations set forth by Severn Trent Water.

Key Requirements:
- Design and draw plans for building over a foul sewer
- Perform load-bearing and foundation strength calculations
- Ensure all designs and calculations are compliant with Severn Trent Water's requirements

Existing Resources:
- I have detailed architectural and structural drawings for the house and the above-ground extension
- I can provide access to the current house and extension plans

Ideal Skills:
- Proficiency in architectural and structural design software
- Strong understanding of load-bearing and foundation strength calculations
- Familiarity with the regulations set by Severn Trent Water
- Excellent communication skills for discussing and explaining designs and calculations