I agree with what Jenste said and would like to add my experience:
I did go the route where I took SSW after my B.A. So in terms of schooling, I did an extra year. However, the year before I decided to go that route, I wanted to pursue teaching degree. I was rejected from teaching colleges and ultimately was devastated which mate me re-evaluate in the direction I want to go in my career. So when I got rejections in mid-Apr 2013, I looked into SSW programs and George Brown was still accepting applications even though it was only 2 weeks until classes start, I got accepted (it was like a day or who before classes started). I know cutting it close...
Last year I guess I was not as competitive for UofT as I was in middle of my SSW and was on wait list all summer long, ultimately rejected. However I finished up my SSW and that helped me get a part-time job in a field, adding to my skills and experiences, to be accepted this year.
In the end I do not regret that one year as it was transitional for me into the social work field, got to network with many future social workers and I found out that it is what I want to pursue ultimately, no matter what. Honestly, for me I got more out of the accelerated SSW then my whole undergraduate degree. lol. So it is for you to decide if you think you are competitive enough or you want to improve on your skills and knowledge.
Fell free to ask me if you got any more questions