Wood is one of the best thermal insulators of nature. This is due to its fibrous consistency, which hold tiny pockets of air. Installing additional thermal insulation between logs results in even greater efficiency.
It is a well-established rule that wood provides better thermal insulation than other building materials. Hence a wooden construction is considered highly energy efficient, resulting in lower energy expenditure during the life of the building.
For example, a 100 square meter wooden house can achieve an inside temperature of 22ºC with an outside temperature of 0-5ºC in just 2 hours. A cement or stone building would need approximately 27 hours to achieve the same results.
The insulation of a house is determined by the heat conductivity of the materials used in construction. In other words, the materials ability to absorb the outside temperature and then transform this heat indoors. Wood has a very low conductivity score as opposed to stone or cement, which results in the ability to heat a timber house a whole lot quicker. According to studies, wood provides around 9 times the thermal insulation that cement, 700 times more than steel and 2000 times more than aluminium respectively.
This is why central heating is very uncommon in wooden buildings. A fireplace and some thermal elements or a simple air conditioning unit is sufficient even at high altitudes.