How to Go About Heating an Attached Garage

Tack insulation between the wall studs of the garage if you haven't already installed drywall over the studs. Use a staple gun and just enough staples to hold the insulation in place. Too many staples will cause the insulation to be flat. Add a few staples at the top, and others spaced every 3 feet down the length of the wall. If you have drywall over the studs, drill a hole to see if there is insulation behind it. If there is none, you need to call contractor to fill the space behind the walls with loose insulation.

Hang drywall. It comes in large sections that are spaced just right for the distance between studs. Screw it to the studs with drywall screws. Check each piece as you hang it to see if it is level. You can hire someone to do this if you prefer.

Spread drywall mud, also referred to as joint compound, over the seams with a trowel and smooth it out. Apply drywall tape to the seams and press it into the mud. Spread more drywall mud over top of the tape. Smooth it over and scrape off the excess. Allow it to dry and then sand it smooth. This will greatly affect the temperature in the garage.

Purchase and have someone install an insulated garage door.

Lay down a garage pad that cars can drive on. Make sure it is a durable pad that cars won't damage. Added layers on the floor will insulate the cold concrete.

Run a kerosene heater if you have vents in the roofing of the garage. The fumes will travel up and out of the vents. If no vents are present, or if you are wary of kerosene, use an electric space heater for large areas or a ventless propane space heater. You can run ventless heaters in areas with less ventilation because the system eliminates the fumes. Look for a heater with an auto shut-off feature so the heater will turn off when the room reaches a certain temperature.