I live in central Indiana in a 2 story, nearly 200 year old farmhouse. This place has been in my family since it was homesteaded in 1847. Been living here 30 years and no plans for ever leaving. Since 2004 I have been heating the downstairs with a Hardy boiler and the upstairs with an electric furnace. I use a RIDICULOUS amount of firewood. I'm planning on a major project this summer. I'm going to build an attached garage, upgrade the electric and plumbing. A lot depends on what the insurance company says, but I'm considering putting in an add-on wood stove in the new garage with a new gas furnace as backup heat. Am I better off doing this or staying with my boiler? I'm also planning a major insulation project. Any thoughts are welcome.

Might wanna check with that insurance co. They ALL seem to have major boners for wood heat.

Check out the outdoor boiler system they have a verity different alternative ways like other boilers and the burning is done away from the house.

Boilers do use a lot of wood. Our indoor stove uses about 10 rick a year.

sounds like you need insulation, maybe foam insulation, where they inject it into the walls from small hole from the outside of the house,

X2

Focus on saving the heat rather than burning more. Much bigger return on your dollar over the years.

Old homes can be a beast on heating costs. Most built with almost none to zero insulation. The only thing insulation was used for was to cut drafts. I had an apartment years ago that was built in the '40s. No insulation. Real bad windows. Place cost a fortune to heat.
If your older home has bad windows , yes , it is a bunch of money to replace them , but that apartment I had , if the windows got replaced with modern windows , they would have paid their way back in heating savings in about 3 years. That's how much heat would get lost. And yes , I did the plastic covering and other things to help , but it is not like a modern properly sealed window.

I burn 15 full cord, is that a ridiculous amount?

Insulation helps no matter the heat, check with the insurance company on a wood burner I know it varies quite a bit from company to company.

Generally a wood heater in a garage is forbidden by an insurance company. They figure it’s not being monitored.

15 cords of nicely split and dried hardwood seems like a lot more wood than 15 cords of random logs tossed infront of the boiler where they're cut up and tossed in regardless of moisture.

I have an indoor wood boiler in the garage with backup LP heat. Works great for passively keeping garage warm, wood is stored inside and the Mrs will fire when I’m gone. Insurance company required the boiler be in its own room with fire rated drywall and door.
Dave

I burn around 10 gallons of 2 cycle chainsaw gas every year, that is a ridiculous amount of wood.

Nothing like a good workout and free heat. LOL

All my firewood is cut, split and stacked on 1 cord racks. Seasoned at least 3 years.

My insurance guy came came by and saw a stack of wood in the yard and said "don't tell me you have a wood stove" I said yes I do. He started talking about my rate may have to go up and I ask if they went down when I took the coal furnace out, did they go down when I put a steel roof on and you won't cover it? I said maybe I should just drop my insurance and save them money I am paying you. I told him they were not going to cover the house if it burned anyway' the way they nickel and dime me if I have a claim. He said you don't want to drop your insurance. I have not heard a word from them about my rates going up and that was a year ago he was standing in my drive way. .

Since you mentioned insurance, I’ll thrown in my experience. Stick with UL approved appliances and follow your building codes. Homeowner applications often ask if improvements were performed by licensed workers. If you falsely say “yes”, you might be disappointed following a major loss.

I had a customer who had electrical work performed by a friend. We dropped his coverage at renewal time. A few months later his wife died when their home burned to the ground.

I burn maybe a cord and a half a year. I have a blaze king princess with the catalic convertor. Great stove. My house is 20 years old with good insulation. My dad has a brick home. Brick and insultion is the ticket.

are we talking face cords or legal cord

a legal cord is 4 foot deep 4 foot high and 8 foot wide or whatever measurement you come up with that equals 128 cubic feet

15 face cords is a normal year with an indoor wood stove for heat

15 full cord is a normal enough year with an outdoor boiler

if you burn 15 full/legal cord of 3 year stacked and dried wood one would have to ask if you A leave a window open or B have no insulation.