Construction defects impact energy efficiency

30.01.2026

Construction defects drastically reduce energy efficiency and sustainability

Defects and errors are common in home construction, resulting in lower efficiency and sustainability. A recent study by the Institute for Building Research (IFB), commissioned by the Building Owners’ Protection Association (BSB), shows this.

The 8 most common construction defects affecting the environmental performance of buildings are:

  • Thermal insulation (material, approval, and execution): 47%
  • Missing documentation: 46%
  • Airtightness (roof and  upper floor ceiling): 40%
  • Windows and French doors (quality, fastening, and sealing): 34%
  • Moisture damage (efficiency): 27%
  • Thermal bridges and summer thermal discomfort: 25%
  • Building systems services (heating, photovoltaics, and heat pumps): 21%
  • Building systems services (ventilation and indoor hygiene): 13%