Who would be best person to help you find suitable fixtures and fittings for doors and windows?
Architects are trained to create designs that are structurally sound, functional, and aesthetically pleasing. They also often have a basis knowledge of construction materials, though not detailed knowledge required when choosing appropriate hardware.
Interior designers specialize in decorating and furnishing of rooms and can offer fresh, innovative ideas and advice, but will be concentrating on appearance rather than how fittings work.Maybe a blacksmith or metal worker would be person to ask.. No, a joiner is best person to give advise.
Joiners understand what is needed, they have made doors and windows and know how big a hinge would be needed to hold weight of a solid oak door, or which lock would fit properly and safely in rebated french windows.