The solution to dense bread

I made 2 loaves in the last few days, one being a Bread Without a Timetable and another the Dill bread, both from Smitten Kitchen. Both turned out pretty good, but somehow really dense.

I figure it's 2 things:
1. My house is not warm. The dough takes more than twice as long to double in size. With the dill bread, it was more like 6 hours compared to the 1.5 to 2 suggested in the recipe. After 2 hours on the counter, it looked almost exactly the same! So I turned on the oven to "warm" for a couple minutes, stuck the bowl of dough in and shut it off, then left it for the rest of the afternoon. It looked great after that.
I did the same for the second rise, except I forgot to turn off the oven that time for about 6 minutes. As it turns out, "warm" is actually pretty hot. After a mad dash to the oven to yank it out, there was a thin crust just starting to form. Oops. Luckily it still turned out okay. :D

2. I don't have bread flour, so I use regular all purpose flour. I think this is the big factor. I am going to try these again with some Vital Wheat Gluten next time and I think they will be much more soft, chewy, and bready-awesome.