How Many Cords of Wood to Heat a House?

How long does a cord of wood last? You know this answer is coming...it depends! Do you like sweaters? Do you live in Missouri or Maine? Is old Aunt Edna visiting at Christmas?

But never fear, this article will walk you through the factors that determine the rate of which you'll burn through your firewood supply.

Heating Degree Days

The biggest factor in wood consumption is average temperature.

A wood stove in Missouri will most likely burn less wood than one in Maine. Warmer states have fewer "heating degree days" than colder states. A heating degree day measures the difference between the average daily temperature and a "comfortable" temperature of 65 degrees. Thus, if the average temperature is a chilly 25 degrees, then the heating degree day would be 40.

By looking at the chart here, you can see that New England averages 5,822 heating days while Texas only has 1,882. The more heating days you have, the more firewood you'll need.

Wood Species

Hardwood like oak will produce more heat than softwoods like pine and fir. Different wood types can burn for different BTUs or British thermal units. For a heating area it will take a specific quantity of BTU to raise the temperature from 32° F to 72° F. The high the BTU output means that there is more heat for a type of wood. This doesn't mean you have to use just white oak bark as wood. The burning of softer wood in the spring and fall has very good efficiency because of the fewer drops in temperature in autumn and spring. The temperature inside will be near 55 °C and it will not demand as much BTU.

I even arrange my wood pile by species. I put the softer woods like maple and birch in the front and back and the oak in the middle. That way, when I begin burning wood in the late fall when it's cool but not too cold, I'm using a less dense wood since I don't need as much heat. By mid-winter when temperatures often drop below zero, I'm working into the oak in middle of the wood pile. By early spring when it starts getting warmer again, the wood stacked in the back of the pile is mostly maple and birch again.

Using this strategy allows me to be efficient with my wood consumption. I can still burn softer "waste wood" to take the chill off but reduce the amount of high quality firewood that I would use over the entire winter.

For example, this chart shows the various BTU outputs of different wood species.

Wood Species BTU Table

Q. 

Heating a whole house or supplementing

The "help" your wood stove gets also impacts how much wood you need for winter. Some sources are obvious like an oil furnace of a propane furnace.

Consider whether you will use other major heat sources or whether the wood burners will be your primary source of heat. Heating an entire house solely with wood uses much more firewood than a wood stove just adding to the heat provided by a furnace or monitor heater.

You might be surprised by other heat boosts like passive solar, how much baking you do, and how many people are in the house! For example, we notice a significant difference an ambient house temperature when we have several consecutive sunny days. We oriented our house to "solar south" and have a masonry heater. So when that sun shines in through those south windows, it helps keep all that masonry warm.

Similarly, on Thanksgiving with an oven churning out pies and a herd of extended family throwing off body heat, we can really reduce how much firewood we use!

Wood Moisture Content

The moisture level of your firewood plays a significant role in burn efficiency. Wet wood doesn't produce as much heat since it essentially has to boil off water content in before it can raise the wood temperature above 212 degrees!

Dry wood burns more efficiently, is clean burning, and doesn't create as much air pollution.

However, wood that is too dry isn't efficient either. It burns so fast that it can't get enough oxygen for a "secondary burn," so a lot of unburned gasses go up the chimney.

To burn wood as efficiently as possible, the moisture level should be between 15-20%. Check out my post on how to season wood properly and also my review on moisture meters.

Windows and Insulation

Allowing heat to escape through wall, windows and roofs is like tossing firewood down the river! I lived in an old farm house as a kid. When the wind blew you could feel it through the windows and it was insulated with old newspaper. We burned 10 cords of wood a year and it still felt cold.

My house now has 5 1/2 inches of cellulose in the walls, 8 inches of foam on the roof, and double pane windows. Now we heat the house exclusively with wood.

Wood Heating Efficiency

Wood stoves vary in terms of efficiency. According to Regency Fireplace products, a non-catalytic wood stove burns two times more wood than a catalytic wood stove. Other sources claim a 30% increase in efficiency with a catalytic stove. Masonry heaters are even more efficient. So, the bottom line is if you have an older, less efficient stove plan on more wood than if you have a new wood stove.

House Size and Design

It takes far more wood to heat an average 2,000-sq. ft. farmhouse than heat an ideal 800-sq. ft. home. Not only that, but layout impacts heat flow as well. Open-concept houses tend to move hear around more easily whereas houses with a lot of closed off rooms make it more difficult to maintain even temperatures. Closed off bedrooms on the north side of the house away from the wood stove may be 10 degrees colder.

You may enjoy piling on the blankets and snuggling into flannel sheets. Or, you might crank up the wood stove...making your main living space even hotter just to drive warmth to the cold recesses of the house.

As a result, you'll go through more wood than you would if you had unrestricted airflow.

Case Studies: How much firewood for winter?

I grew up in a large, drafty farmhouse in Maine...on top of a hill with a lot of wind! Although we had a furnace as back-up we seldom used it. So, 2200 square foot old farmhouse in northern New England with non-catalytic stoves and little to no insulation and we burned 10-12 cords a year.

The first house I built was an 1800 square open-concept chalet. The insulation was decent, the windows were double-paned, but the house faced north (had to face it that way because of the lake!) so it tended to be cold. I had a catalytic stove, used the furnace occasionally, and would typically burn 5-6 cords of wood over a cold winter.

Now I'm in a pretty efficient house. Great insulation, great windows, facing south for passive solar, use a highly efficient masonry heater, and in a typical winter, I'll burn four cords.

Measuring fire wood

Difference between full cord and face cord

How much wood is in a cord?

A cord of stacked firewood measures four feet wide by four feet tall by eight feet long.

A face cord measures 16 inches wide by 4 feet tall by 8 feet long.

Most firewood dealers are reliable and accurately deliver what you've paid for. But it's not a bad idea to spot check someone who you don't know. Even though it takes a bit of work, knowing what a cord of wood looks like in a pile will ensure that you get full cords.

Stack wood until you get 4x4x8'. Then throw it into a pile. Stake out the pile and measure the space so you know how much wood is in that area. (It's also not a bad idea to invest in a moisture meter so that you can see how dry your "seasoned" wood is when it arrives!)

Tips for Purchasing Firewood

You can't have too much wood

I suppose you could...if you bought 20 cords of pine and let it sit out in the rain for 5 years. But, if you keep it covered it will last indefinitely. So buy more than you. think you will need. You DEFINITELY don't want to trying to find dry wood in the middle of March. It will be tough to find and even if you do..it'll be pricy! So keep an ample wood supply in your shed!

After a few seasons, you'll get a better sense of how many cords you'll need and can plan accordingly.

Shop Around

Most people who sell firewood are honest, hardworking folks. Some are more honest and hardworking than others. So ask around and see who has the best reputation. You might even consider buying a cord from two or three different sellers and see whose "full cord" is the largest!

Also, use a moisture meter to verify exactly what degree of seasoning your firewood has. (Check out my article on moisture meters here!). Again...most firewood dealers are honest...some are more honest than others.

Get Wood Early!

Don't wait until October to order your wood for the season. Everyone is thinking wood heat that time of year...prices go up...sellers are busier and less relaxed. Try getting wood delivered in the beginning of summer so that you have plenty time to get it stacked and out of the weather before the snow flies. And while you're at it, get your chimney swept, too!

Is Wood Heat a Lifestyle Choice?

For some, wood heat is a lifestyle, not necessarily a chore. What I mean by that is this. For some, cutting, splitting, and stacking wood is an activity that is part of life...so they don't mind doing it. It's just something they do. So instead paying for pre-processed wood (and a gym membership!) they do it themselves by either cutting their own firewood or having it delivered in tree lengths and processing it from there. (Which is much cheaper!)

But if you don't have the time, high quality wood cutting tools, or the interest in playing lumberjack, then you should buy pre-cut and split wood. Just know what you are getting yourself into!

Heating with wood burning stove is labor intensive

Remember that heating with wood warms you twice...at least. The physical work of cutting, splitting and stacking your own firewood warms you once. Then when you burn it, it warms you again!

Heating your home with cord wood becomes a lifestyle. You spend weekends processing firewood. Be the ant and not the grasshopper and budget time to manage your heat source! Also, consider any physical limitations you might have. If you experience back pain or have a torn rotator cuff, swinging an 8-pound maul won't be good for you!

I really like spreading the work out in short chunks over a longer span of time. For example, I harvest wood in the early winter months, dropping trees and bucking them up. (I work two years ahead of time to allow enough time for the firewood to properly season).

Over the course of the winter I start splitting it working in half-hour sessions and getting it stacked up to dry.

I'm too busy to do much in the summer, so I don't do anything..and in the fall, I do any moving or stacking of dry firewood for the upcoming winter.

Firewood Prices 2021

Cut, split, seasoned per cord of wood

Maine $200-350

Ohio $200-300

Kentucky. $150-250

Colorado $250-325

Frequently Asked Questions

Q. How much does it cost to heat 2000 sq ft of wood?

A. At $250 a cord, at 6 cords a winter...$1500

Q. Is a wood stove enough to heat a house?

A. Yes. If you have the right stove and a heat efficient house

Q. Can you run a wood stove all day?

A. Yes.

Q. How often do you put wood in a wood stove?

A. It's tough to say exactly how long wood will burn. It depends on the density of the wood and the amount of air coming in to the fire. A full load of hardwood with very little air can burn slowly all night. A load of pine with a lot of airflow will burn up in less than an hour.

Q. How do I control the temperature on my wood stove?

A. With the kind of wood and air flow. Hardwood and more air increases heat. Turning down the air vents will make the fire burn more slowly and also burn less wood.

Q. How many square feet can a wood stove heat?

A. It depends on the stove. This Ashley can heat 1200 square feet. The Vermont Castings Defiant throws out 56,000 BTU's and can heat up to 28,00 square feet.

Q. Is heating with wood worth it?

A. Considering just the finances, yes. Let's say an oil furnace costs $5000 installed and the "average" home burns 800 gallons a year at $3.30 gallon. That's $2640 in oil. So 10 years of heat would cost a total of $31, 400.

A high quality wood stove cost around $3000, and the average home burns 6 cords of wood a winter at $250 a cord. That's $1500 in wood. Over 10 years, the heating cost is $18,000.

So, financially, the numbers favor wood heat. The question is...is it worth it in time and effort? With oil, you just set the thermostat. With wood, you have to cut, split, carry and tend the stove.

Q. Can I heat my house with wood?

A. Yes.

Q. Is heating with wood cheaper than gas?

A Natural Gas and propane closely follow heating oil prices, so, yes, heating with wood is cheaper than gas.