The key to firewood... what to cut?

For several years now, our Sustainable Family has been using wood as our primary heating fuel during the winter.  Since we started, I've been raving about it to everyone who will listen and have even managed to convince a few of my friends to make the switch.

In general, we use about 3 cords of wood per winter to heat our approximately 1700 sq. ft. house.  If you are thinking about burning wood during the winter months and are trying to guess how many cords of wood you might use, I will tell you that it is dependent on a lot of factors that are individual to each home and stove set-up, so it might take you a few years to figure it out.  You can use our experience as a rough guide, but my recommendation is for the first couple of years guess higher than you think.  Stacking an extra cord of wood is not much more work, and if you don't use it for winter heat you can always use it for campfire wood during the summer, or even use it the next year if you can keep it relatively dry and off the ground.

If you currently heat your home with wood, you know there are a couple of ways to get your fuel, either ordering it seasoned, split, and delivered for about $200-$250 per cord, or if you have the land available, drop it, cut it, and split it yourself for free* (*plus cost of chainsaw, chains, gas, bar/chain oil, hydraulic splitter, etc.).  The rule of thumb is for every acre of hardwoods you have available, you should be able to get that many cords of wood each year for eternity by cutting only the largest trees.  So the next logical question is how can you tell how much cord wood you'll get from a tree before you drop, cut, split, and stack it? 

The key to calculating cord wood from standing hardwoods is the diameter of the trunk at about 4 ½ feet from the ground.  If you have a flexible measuring tape (like a 100 ft. roll tape measure) the process is even easier, but if you don’t, you can use an ample size piece of rope and a regular metal tape.  Here’s how it’s done:

1. Figure out where on your body is about 4 ½ feet from the ground.  I had my son measure on me and it ended up about mid-chest, so I’m guessing for a 6-foot tall man it is right about armpit height.
2. Wrap your flexible tape measure around the trunk of the tree at this height and note the circumference in inches.  Or if you’re using a rope, mark the rope at the overlap point and measure the length of the rope.
3. Divide the circumference in inches by 3.14 to get the diameter of the trunk.
4. Use the chart below to determine how many cords of wood you can get from the tree.

Source:  University of New Hampshire Cooperative Extension. 
 
This method has worked pretty well for me in the past so I hope your experience with it will be the same.  Now the trick is knowing when we’re going to have an abnormally mild or cold winter so you can really maximize your conservation!  Let me know when you get that one figured out.