According to the HomeAdvisor survey, nearly eight in 10 Americans are concerned about higher bills this winter. Small holes in foundation or siding, including anywhere pipes or wires penetrate the envelope of the home, can cause serious heat loss and increased costs. So how to keep your house warmer this winter? Part of your maintenance planning should include using spray foam insulation to seal those cracks and, if you need more insulation in your attic, hiring a contractor to use spray foam insulation or install additional insulation throughout.