The three common ways to heat your tiny house are using wood, propane, or electricity. Because I was building off-grid, using electric heat was out of the question. The battery bank can not keep up with something running constantly at 1,500 Watts. So it was between wood and propane, and I chose to use both. I love wood heat; I mean, who doesn't? There's something calming about relaxing in front of a wood stove in the evening. That being said, in my case wood couldn't cover the entire burden of heating my house. What if I want to head out of town on a ski trip? I couldn't let the pipes freeze, so I needed a backup that could run while I was away from home. So, propane. I already had the intention of plumbing the house for propane for cooking and hot water, so adding a heater was just another step.
Wood is a dry heat, where propane is wet. Something to take into consideration when building a tiny house. Because the volume of the house is so small, moisture buildup is very rapid and can turn into a problem. Using wood heat can circumvent this problem, but if you decide to go with propane, you may want to consider using a dehumidifier to control the humidity.