design and calculations required for loft conversion

velux loft conversion on 2 bed semi. Probably need to lower 1st floor ceilings to get required headroom. Also wish to remove a load bearing wall to create a landing area and remove a chimney breast, both on the 1st floor. I need a design, all drawings and calculations to submit to building control. Can submit measurements and photographs so remote working is possible, however a local architect who can do a site visit would be preferred.