Checking of Structural Calculations and drawings

Structural Engineer needed!

I have had some structural calculations completed and require someone to completed by a freelancer and require someone to provide a second opinion and check them as there seems to have been a misinterpretation of the requirements.

The calculations are for a single storey kitchen extension project. We need to knock through the external wall and another supporting wall and put some Timber structural beams in.

The freelancer has produced drawings with floor joists in the extension however i have spotted some issues

- it is only single storey extension and for some reason they have placed floor joists in there
- there is a gap where there should be floor joists from the upper floor
- it is not clear if the beams require a lintel or not.

I would also like to understand the implications of running the beam across the whole length of the building (5.59m) as we have an option to move the drain