If you’ve got a wood-burning stove in your rural home, farmhouse, cottage, or off-grid-cabin, the question of “how many cords of wood do I need for the winter?” is sure to cross your mind sooner or later.
This can be especially daunting if you’re new to using a wood-burning stove for heating. How do you calculate the number of wood cords you’ll need to last the whole winter? How much should you stock up on to avoid running out of firewood halfway through the winter?
The answer isn’t so clear-cut. Figuring out how much wood you’ll need depends on a number of factors and is more of an art than a precise science. The more experience you have heating using a wood-burning stove the better you’ll be able to estimate your firewood needs.
However much firewood you think you’ll need, one thing to remember is it’s always better to err on the side of too much firewood instead of too little. That way you won’t be scrambling to get more firewood in the middle of frigid sub-zero temperatures.
Let’s take a look at some of the key factors influencing how many cords of wood you’ll need for the winter, and go through some real-life examples to help you estimate your firewood needs.
Before we get into the meat of the article, it’s important to have a good grasp of how firewood is typically measured.
In North America, firewood is typically sold and measured by the cord. A cord is a measurement of volume that measures 4 feet by 4 feet by 8 feet. This equates to 128 cubic feet.
As it’s not a weight measurement, the actual amount of firewood in a cord can vary based on how neatly it’s stacked. A haphazardly stacked cord will have more air gaps in it, resulting in less useable firewood. Whenever you’re buying firewood, you’ll want to make sure the cord is neatly and tightly stacked.
When planning out how much wood you’ll need for the winter, keep in mind you’ll typically be measuring it in cords. If you’ve calculated that you’ll need 3 and ½ cords, rounding up to the nearest full cord will ensure you won’t run out. If you don’t burn much firewood, or if you use a wood stove as a secondary heating method, then you can often purchase a face cord of wood, which measures one-third of a full cord.
Factors Influencing Firewood Usage
Now that you have an understanding of how firewood is measured and sold, you should be able to estimate your needs more accurately. Let’s examine some of the factors to consider when calculating how many cords of wood you’ll need for winter.
Your local climate and winter temperatures will have a major impact on how much firewood you’ll need. Northern locales have longer and colder winters, so if you leave in one of these areas you’ll need more firewood than someone living in Georgia for example.
Similarly, the Northeast and Midwest tend to have longer and colder winters than the West coast.
Depending on where you live, the wood-burning season can start as early as September last as late as May. You’ll also want to take into consideration how a particularly cold winter will increase your need for firewood. Once again, it’s a good idea to err on the side of too much wood rather than too little.
Another important factor is whether or not firewood is your home’s primary heating source. If you heat primarily with natural gas or propane, and firewood is just a backup heating method, then your firewood requirements will be significantly less than someone heating exclusively with firewood.
Also, how often you use your wood stove will influence your wood usage. If the place is a secondary property like a cottage, then your wood usage won’t be anywhere near someone living in their place full-time. Additionally, if no one is home during the day, your needs will be less than if you have family that’s home during the day.
While heating with a wood stove certainly requires more planning and legwork than other heating methods, it has the benefit of working regardless of power outages. In most cases, you’ll also end up saving money when compared with other heating methods.
The square footage of your home will influence how much wood you’ll need.
Naturally, the larger the space, the more energy will be required to heat it. A 2,500 square foot house will need a good deal more firewood than a 700 square foot cabin.
Larger spaces may also require multiple wood stoves to heat effectively, which can double the firewood needed to keep both stoves burning at the same time.
This is actually a major consideration when it comes to heating using a wood stove. A well-insulated home makes a major difference in terms of keeping heat trapped inside your home, and will result in less heat wasted as it leaks through gaps in the insulation.
Sprucing up your home’s insulation will cost a bit of money upfront, but over time it will save you money, as you’ll be able to heat the same space with less energy. The most common ways to improve insulation are by replacing old single-pane windows with newer energy-efficient models, fixing any drafty window frames or doorways, and repairing or replacing old, damaged insulation.
Your stoves output and efficiency both have an impact on your firewood use. In general, modern wood stoves are highly efficient at increasing the heat output for each piece of wood burned.
You’ll typically find efficiency levels between 60% and 90% for these wood stoves. This is especially true when you compare them with burning wood in an open fireplace, where a huge amount of heat is lost out through the chimney.
If you don’t already have a wood stove, then it’s a good idea to consider a high-efficiency model. They typically cost more than lower efficiency models but will save you money in firewood expenses over time.
Wood Storage Space
One thing you might not have considered is how much space you have outside your place to store firewood. Firewood needs to be kept somewhere where it’s protected from rain, ice, and snow, so think storage shed, empty garage, or a DIY firewood storage rack.
Storing your firewood poorly can lead to it absorbing moisture, which will cause it to burn poorly in your wood stove. If you don’t have adequate firewood storage already, consider building or buying some type of firewood shelter.
Type of Wood
This is another factor you might not have thought of, but the type of wood actually has a major impact on how efficiently it burns and heats your home. Generally, hardwoods are preferable to softwoods, as they tend to burn slower and create less smoke.
Hardwood species are denser than their softwood cousins, which results in a clean-burning fire that needs less tending and creates less ash and soot buildup. They have a low and slow-burning rate when compared with softwood – which is exactly what you need when heating an indoor space.
Softwoods can also be used for heating, but keep in mind they have several drawbacks that make them less than ideal for firewood. They burn fast, which means you’ll go through more firewood for the same amount of heat. This also means these fires require more frequent tending, so they’re less than ideal for keeping you warm through a cold night.
Lastly, softwoods create a lot of smoke while they burn. This is fine if you’re having an outdoor campfire, but it’s less than ideal when burning indoors in a wood stove. The smoke can cause soot and ash buildup inside the chimney, which means more maintenance and more frequent cleaning.
Hardwoods come from deciduous trees including:
Softwoods come from evergreen (coniferous) trees including:
Another related factor is the level of moisture remaining in the firewood. Properly dried firewood is commonly referred to as seasoned wood, which is wood that’s been dried to below a 10% moisture level.
Ideally, seasoned wood is what you want to be burning in a wood stove, although sometimes you’ll end up with wood that’s somewhere between seasoned and green wood. This is especially true if you cut and dry your own firewood.
Green wood is firewood that’s freshly cut and hasn’t yet gone through the seasoning process. It can contain up to 50% moisture. This type of wood will create a lot of hissing and crackling as it burns, as the trapped moisture needs to evaporate before it can burn properly. Avoid burning green wood if at all possible, as it’s inefficient and can cause creosote buildup inside your chimney.
If you’ve come this far, you should have a pretty good understanding of the factors influencing firewood usage, but you may still be wondering how to apply all of this to a real-world situation. Let’s take a look at a few realistic scenarios in order to illustrate how you can estimate your firewood needs for the winter season.
Scenario 1: 1000 Sf. Cottage
Let’s say you’ve got a newish 1000 square foot cottage in Northern Vermont that’s heated primarily with a wood stove but has gas heating as well. It will need to be heated daily during the evenings and weekends and is in reasonably good shape in terms of insulation. The wood stove is new and high efficiency.
Northern New England tends to have long, cold, and snowy winters with temperatures below freezing for large portions of January and February.
In this scenario, you can expect to go through 2-3 cords of firewood for the season. Of course, there will be some variability depending on how cold or warm the winter is, so erring on the side of too much wood is a wise move.
Scenario 2: 2000 Sf. Rural Home
Assume you have an older 2000 square foot house in rural Northern Michigan that’s heated primarily with two wood stoves. It will need to be heated for the whole day, as you have family members at home during the daytime. As it’s an older home, the insulation is not in great shape, and there are some gaps around windows and doorways. The two wood stoves are both newer and high efficiency.
Northern Michigan has cold, snowy winters with most of December, January, and February being featuring subzero (below 32°F/0°C) temperatures. The temperature is moderated somewhat by the slow cooling great lakes, but you can expect a lot of snow.
In the scenario, you’re looking at burning 6-8 cords. Once again this will vary depending on how cold the winter is, but this should give you a good estimate of how many cords of wood you need for winter.