Traditional stick-framed homes and structures are less energy-efficient than SIP homes because they are more prone to energy loss (or gain if the climate outside is warmer than inside the home) because of thermal bridging and air leakage.
For instance, about 40% of an existing home’s energy loss is from air leakage. Air leakage is measured in air changes per hour (ACH). The current International Energy Conservation Code (IECC) requires a typical stick-framed home to have an ACH of 3-5 depending on climate zone; a SIP home can achieve air leakage as low as 0.2 ACH using energy-efficient construction procedures. Simply reducing the amount of ACH can significantly lower your energy bills.
There are other advantages to reducing the number of air changes per hour. For example, there are fewer drafts, meaning less dust and other allergens entering your home.