I need structural engineer

I need a structural engineer to do calcs on a timber framed shelter/building for a leisure park. ive attached a scale drawing. all timber beams are C24 pressure treated spruce. posts are 150mmx 150mm thick, ring beams are 45m x 145mm c24, rafters are 45x120mm c24. clad with 17mm T&G planks and covered with felt shingles 11kg per m2.