Are you done losing weight?
To concentrate on building muscle, you do need a surplus of calories. This doesn't really help with weight loss though. If you look at a typical bodybuilder's schedule they have cut and bulk phases (I'm not implying that you're trying to become a bodybuilder, but this is a good example for how this works). They will spend a portion of their year bulking - lifting heavy, usually little to no cardio (ever wonder why the super muscle guy gets easily winded by a flight of stairs?), and eating a surplus of calories. They will add muscle but also add fat at the same time. Then whenever they are closer to "show season" they will go on a cut - they will reduce calories and do cardio to try to lose the fat. They will continue to lift hard to try to mitigate the loss of any muscle.
Generally speaking, it's my understanding that while you're trying to lose weight the name of the game becomes to try to NOT lose muscle. You do this by strength training. (There are beginner gains where for a relatively short period of time a total strength training newbie can gain muscle while in a caloric deficit, but that levels off after a relatively short window of time)
Once you're done with weight loss, you can switch to your own version of a bulk phase to concentrate on adding muscle. I'm very curious to see how this works out for myself. Once I get to goal, I don't know if I can physiologically switch to purposely eating surplus!
Hope this helps