Energy efficiency drives real estate premiums and insulation risks

Energy efficiency improvements in German real estate present both financial premiums and physical risks. According to the Postbank Wohnatlas 2026, buyers of highly efficient homes (classes A through D) pay an average premium of 759 euros per square meter compared to less efficient properties. In regions like Miesbach, Bavaria, this premium can reach approximately 3,133 euros per square meter, representing a nearly 49 percent increase in cost.

However, improper insulation can lead to structural issues. A case report from VHV highlights how internal insulation in a 1960s apartment improved the U-value from 1.24 to 0.51 W/(m²K) but caused moisture and mold growth. Because the insulation was applied to the interior, thermal bridges at window reveals and ceiling connections remained cold, leading to persistent dampness that regular ventilation could not resolve.