Hi Laura, I came across this post and as someone who has studied Interior Architecture & Design at University and has been through exactly what you’re going through right now, I thought it would help you to hear what I went through too. Not sure if you’ll see this reply but I hope you do!
First off, I feel like your Art teacher doesn’t know what she’s talking about. My Art teacher told me the same thing and I ended up struggling for the first semester or two at university. Decide for yourself if you want to do Interior Design or Interior Decorating. They’re both different things. Interior Decorating is picking out furniture or perhaps custom-making it, putting colour themes together and sourcing materials, supplies, creating mood boards etc. Sometimes people confuse Interior Design for Interior Decorating but Interior Design is much more than that. Interior Design is drawing plans, elevations, technical details, furniture, window and door schedules, writing briefs, doing site and building analysis, social and environmental mapping, building regulations, health and safety and much more.
I’d say if you’re leaning more onto Interior Design, the architectural and building side of things (building and designing furniture for example), take DT. In DT you’ll get more of an opportunity to tamper with computer programs like CAD software and 3D building software, which is a good thing to start doing now because a lot of the Interior Design / Interior Architecture courses in the UK place a heavy emphasis on students being able to use programs like AutoCad, Vectorworks, Sketchup, Revit or 3DSMax.
If you’re leaning more towards Interior Decorating, take Art & Design. Even though GCSE and A-Level Art & Design is mostly fine art based, you do get more of an opportunity to tamper with colour, materials and textures. If you end up taking Art, there is also the opportunity after A-Level to take an Art Foundation course for 1 year, where you get to experiment in different Art & Design fields and get a taster of the different design industries, including Interior Design. There are also other foundation courses specifically for Interior Design but they’re typically two years.
If you do take DT, it prepares you better for an Interior Design course and you probably won’t need that extra year for a foundation course. If you take Art & Design it prepares you well for an Interior Decorating course. If you take Art & Design but want to go into Interior Design instead, I recommend taking the foundation course before you go into uni because it prepares you better.
A foundation course isn’t necessary though. I myself went from taking Art & Design in GCSE and A-Levels, straight onto an Interior Architecture & Design course in uni. I just found it much harder in the beginning and had to take extra time out to read and teach myself about Interior Design. If I had taken DT, it would have made things a lot easier.
So that’s it really. If you want to be an Interior Decorator, do Art & Design. Interior Designer, take DT. You can get a university course with either qualification but DT just makes life a lot easier for you if you decide you want to do Interior Design.
I hope this makes sense and I’m not too late because I understand that you’ve probably already chosen your options for next year (you can change your mind still though!)