The cost of your heated garage is going to depend on a wide range of factors. The first consideration will be the size of the garage. The larger the garage, the higher the cost to heat it. The climate in your area will also be another important consideration. Those that live in colder climates spend more on heating the garage in the cooler months. The last thing to consider is the type of heat you will use to heat the garage; natural gas is cheaper to run over the long haul.
The cost to insulate the garage will usually run you around $500. This cost will include purchasing the insulation, weather stripping, caulk, and plastic sheeting. You will need enough to cover all of the exposed walls and cover them tightly with plastic sheeting. If you have drywall installed in your garage you will need to blow foam insulation into the walls with an insulation blower.
There is no point in heating your garage if you aren’t going to insulate the garage door. You can lose quite a bit of your heat through an un-insulated door, and lost heat translates to lost money. You can buy a kit to insulate your average sized garage door for $100 to $200.
You will also need to add heavy duty caulk to all of the windows and doors. Adding weather stripping to the bottom of the doors will also keep out cold air out and hot air in. These extra shouldn’t run you more than $50.
The cost of the heater will be determined by the type of heater you decide to purchase. A small electric heater will require the least initial outlay. However, this type of heater probably won’t heat more than a very small space. If you want to use a larger electric heater, you will have to run a 240 v circuit to accommodate the larger electric load. The most popular choices for heated garages are forced air heater or low-intensity infrared heater. The forced air heater is going to be least expensive of the two to purchase, however, the low-intensity infrared heater requires less energy over time. To heat an average, two to two-and-a-half car garage you will spend between $600 and $1500.
The cost to run power to your garage is going to be the most volatile variable. The market rate for electricity or natural gas is going to be the determining factor. The easiest way to figure this out is to look at your last bill. Once you know what you are being charged for gas or electricity, you can estimate the cost of heating the garage. You will need to know the BTUs on your heater and the size of the garage. It will help to know the temperature you want to keep the garage as well.