building a training room inside my gym ADVERTISEMENT 724 viewsSeptember 21, 2016 0 Kalyn September 21, 2016 0 Comments cost to build a 1500 sf cardio room 8 Answers ActiveVotedNewestOldest 0 Nancy7 Posted 0 Comments That really depends on what you want in it. The floor will be a big investment, and you’ll need to decide what kind of flooring you want. Mirrors? Wall mounts for TRX? Lots of variables. You are viewing 1 out of 8 answers, click here to view all answers. Register or Login