Even if you've succeeded in creating an ideal space for writing in your home, there are times when you'll need a change of scenery to feed your creativity.
Take your laptop to a local coffee shop, or try working in your local library. Watch the people there, pen in hand. Look for dialog ideas, new character tics and traits. Watch young people and old, housewives and businesspeople. Watch the scruffy screenwriter dude on the other side of the room--yep, the guy who's doing the same thing you are.
Or take a spiral notebook and a pen to a private and idyllic place outdoors. Sit alone on the grass and soak in the inspiration. Nothing puts your mind into a creative and eloquent state like the natural world.
If you're looking for new ideas, inspiration--or better still, character ideas--sometimes you just have to get out of the house. Look for new ways to see things, and it will help you find different ways to say things.
One last point: you might find that the place where you're most productive isn't your home at all! Better to find this out sooner rather than later. This is why it's important to tinker with your setting every so often.