Heating your home with firewood can be incredibly rewarding. It’s cheaper, arguably more effective, and more comfortable than any other method of heating a home. More than anything, however, it is simply more satisfying, particularly if you grow, harvest, and process your own firewood. Unfortunately, the benefits come at the cost of increased planning and responsibility. If you run out of firewood during the winter, you can’t easily call on a firewood truck to come and bail you out like you can with oil, so it is important you stack the right amount. But how much firewood do you actually need for winter? In the northern United States, 4-5 cords should be enough, while only 1-2 will be necessary in the south. Luckily, we have compiled state-specific and constructed an estimate for the cords needed for the local conditions in each state. That said, It is a highly variable question based on a myriad of factors, so be aware of any anomalous circumstances that may affect you. In this article, we will discuss everything you need to know.
How Much Firewood is Needed in Each State
Before we get into the nuances of firewood planning, let’s look at the raw data. Below is a map of estimates for how much firewood an average-sized home would need to heat through the winter based on average winter temperatures and a decent firewood species containing 23 million BTUs per cord.
As you can see, the data varies drastically. Alaskans would do well to stockpile seven cords of wood (or more!) while Floridians can get by on just one, which would primarily just be used to take the edge of the occasionally chilly night.
Factors That Determine How Much Firewood You Need
Even within a single state, there are factors that influence the best number for the individual and region. Let’s look at what these factors are.
House Size and Insulation
As all oil burners know (some begrudgingly), not all homes are created equal. It is a basic physical principle that larger homes are going to require more energy to heat than smaller homes. So if you have a big house, you may require twice as much wood as is marked on the map. In most cases, however, homes that burn firewood are average size or smaller, but even then, you may require more wood.
Even between similarly-sized homes, the insulation may differ drastically, leading to substantial heat loss in some homes over others. If you live in an older house or a home that is has known insulation problems, you should plan on bumping your inventory up a cord or two.
Wood Stove Efficiency
Another factor that may affect how much firewood you need for winter is the efficiency of your woodstove. A cord of maple firewood may contain around 23 million BTUs per cord, but not all of that energy is going to be able to be transferred into usable heat for the house. A certain percentage will escape through the chimney in the form of heat and un-combusted particles. The total percent of the wood’s energy that can successfully transfer to the home is known as the stove’s efficiency.
These days, most woodstoves are fairly efficient, but if you live in a home or small cabin with an older woodstove, the efficiency may be considerably less. Don’t underestimate the effects this can have. Personally, at my camp in Maine, I used to burn wood in an old pot-belly woodstove from the 1950s. When I switched over to a modern woodstove, I was shocked at how much better it heat the room!
Species of Firewood
There is also a major difference in energy content for different species of firewood. The estimates above are based on a normal hardwood energy content, but there are some species, such as oak, that may hold even higher energy levels per cord, while there are other significantly worse woods, such as cedar, that hold roughly half the amount of the levels we used. To determine the best species to burn, a helpful guide can be found here.
Severity of Winter and Micro Climates
Of course, one of the most significant factors that influence your firewood consumption is the severity of your winter and the micro climate you may live in. The problem with the estimates given in the map above is that they are based on state-wide averages for winter temperatures, and averages can be incredibly misleading. For example, where I live in Maine, 5 cords may be a great estimate for the central part of the state, but only 4 may be necessary down by the coast, where the effects of ocean warmth dampen the effects of winter. Likewise, 6 cords may be necessary in the far north, where winter mornings often reach far below zero.
Mountain states out west create similar problems. The effects of elevation can create drastic differences over very small distances. In these cases, using a state average is not very useful. It is best to evaluate your local climate and match it with another state that best represents your conditions.
The Best Way to Get an Accurate Assessment of Firewood Needs
That said, data can be tricky, and no matter how much evidence-backed science and statistics there are behind a certain answer to how many cords of firewood you need to survive a winter, these numbers can fail against the ultimate test of reality. Instead, perhaps the best way to determine the most optimum inventory is local wisdom. Ask other wood burners around your area how much firewood they go through. Ask how many cords they burned during the worst winter they’ve experienced. Then ask a few more people. After a few conversations, you will find you have a pretty good idea of what the consumption is in your area. Experience is the best guide, so don’t be afraid to call upon the experience of others!
You Should Plan on Storing More Firewood Than You Need
Particularly if you are burning wood for the first time, it is good to plan on stacking more wood than you think you need. As long as it is lifted off the ground, firewood does not rot easily. It will still burn fine a year or two later, so having more inventory than you need gives you a good margin of safety to put your mind at ease. After a year or two, you will have a decent idea of what your usual consumption is, and you should be able to plan with reasonable accuracy. Until then, over plan! Have fin stacking!