Structural Engineering

am in need of a structural engineer who can assist me with a residential building project in the construction phase. We have rear extension already and will be building side extension to the house, please advise cost to prepare drawings- we would like to minimise amount of steels to be introduced, we also want main supporting beam to have floor joists from room above recessed into the beam and not being supported under ( to gain as much height as possible). Here are the details:

Type of structure: Residential building

Architectural plans: Yes, I have detailed plans available for reference.