If your hydrangeas are the kind that bloom on "old wood" that means they will bloom next year on the growth that they put on this year. So DON'T prune the ones that didn't bloom. Not at all, until they bloom again. Then just prune off the spent blooms when they finish and turn brown.
The most common reason for hydrangeas not blooming is pruning too late, so stems that were getting ready to bloom were cut off. Or, as Pandora said, if they freeze back in the spring, that can also "prune" the new growth where the blooms would be.
So the explanation of why the one in front bloomed and the ones on the side of your house didn't might be as simple as temperature. If it stays warmer at night on cold nights out front (is it the south side of the house?) then that hydrangea may have been protected enough but the others weren't.
Keep a "weather eye" on the temperatures in spring when the buds are coming along, and cover those bushes on the side of the house with something like an old sheet or blanket if a late frost threatens. (don't use plastic! It doesn't help)
