measure your walls and ceiling thickness, noting any differences between
additions and the original structure
figure out whether there is insulation in your walls and ceiling
if you find dissimilar materials, it may be easier to calculate them as
separate structures. (remember that there is no loss on shared walls)
Calculate the area of your walls and ceiling:
Stand outside your home and draw a diagram of its footprint.
Measure the length of the walls and note the measurements on the diagram
Draw a diagram of the elevation of your home, measure and indicate
the height of any wooden portion up to the edge of the soffit, and the
height of the masonry portion. (if your home is a split-level it may be best
to measure each part separately
multiply the wooden wall height by the total of the perimeter length
subtract window and door space
multiply the masonry wall height by the total of the perimeter length
subtract window and door space
calculate the total area of each type of window and door
divide the footprint into rectangles, and calculate the area of these
rectangles and add them together
Step 2: Input the areas into the load calculator.
Fill in the slots that apply, leave the rest blank
only use the areas that are heated. If the basement is unheated, don't use
the portion of the walls below the first floor
Keep in mind that any measurements that you forget to enter will result in
an underestimated load
For increased accuracy, you can include fractions of a foot as a decimal.
If you choose to be sloppy in your area measurements, always round UP
to the nearest foot.
