Strictly speaking, interior architecture is a subject and not a profession.
The designation of the term ‘architect’ is protected, like doctor, and cannot be used by anyone who does not have the specific qualifications and accreditation.
Today, ‘interior architecture’ as a term has come into use due to the increasing scope and responsibilities of interior designers. The role of an architect and an interior designer are commonly debated and especially in recent times, due largely to improvements in design technology (CAD). Many design courses teach students about the structural technical elements of buildings and the line between interior design and architecture has begun to blur as graduates of both degrees leave university with the same skills.
For those with a design degree, the role of any two different graduates may differ drastically. One may be more concerned with decor, soft furnishings and residential projects (a job a lot like an interior decorator). Another may be more concerned with planning and design. This includes feasibility studies, space planning and design concepts. The latter will be more likely to have studied interior architecture.
The practice of interior architecture requires designers to consider pretty much everything to do with the building of an interior space that will affect human habitation, including materials, finishes, electrical requirements, plumbing, lighting, ventilation, ergonomics, and intelligent use of space.
Interior designers with training in interior architecture will usually be present at, and have an important say during all stages of the construction process, from the initial plans right through to the finishing touches.