The media has distorted the public's perception of interior design. Know that the industry is a professional trade just like dentistry, accounting, marketing, etc. As a designer who has obtained a one year certificate, a three-year diploma and completed a four-year degree in interior design, I want to answer your questions and clarify any confusion. 

Based on my experience, a certificate doesn’t come close to the knowledge and skills you build within a degree program. In a degree program you explore all types of interiors, residential, retail, hospitality, office, public facilities (recreational centers, gyms, spas, etc..), healthcare, education, and transportation). By the time you complete a bachelor degree, you will not be limited and know how to tackle any sector of design. 

Most certificate programs only cover residential design and basic design skills. The certificate I completed was issued by the Interior Design Institue of Canada, which consist of dominantly theory-based lectures. I learned about the interior design history, interior design styles, scale, color, textiles, furniture styles and basic drafting skills. 

The three-year technical diploma is great but may limit your career growth as most interior design and architect firms internationally require a bachelor degree.

During the 3-year program which I completed at Dawson College in Montreal, Canada, I learned so much! I developed both technical and creative skills that I didn't have since I have a background in sciences and finances. I learned to tackle residential and commercial projects such as retail, hospitality, recreational, wellness and community centers. I even learned how to design elevators, doors, light fixtures, and furniture. Majority of the courses in the program was hands-on which enhanced the learning process. 

The transition from a technical college diploma to a university degree was very challenging. It does take dedication and motivation to reach the final stage. The degree program was substantially and prominently theory based. It required hours of weekly readings and essays. I was required to complete term papers on environmental economics, design theories, design perspectives, globalization, and many other topics. The main project that is concentrated in the 4th year is a thesis research paper. After completing the research phase, I finally had the chance to put into action my technical design skills and integrate evidence-based design into an actual project. All this to say is that the degree program is much more enriching, credible and valuable than a certificate in interior design. 

My advice to you is:

Know what you want to do. Don't confuse interior decorating with interior design. Research different schools in your area that offers an interior design program and take a look at their course outline. Go to the open house or request a visit. I share all this with you because I've seen many people drop out of the program simply because it's not what they expected. I don't want you to waste your money, time and energy! 

If you've done your research and you know without a doubt that interior design is for you, I want to wish you the best of luck and congratulate you for taking this step. The education part is a lot of work but I can testify that it is SO WORTH IT in the end!!!!