Future of construction methods with higher densities

To assess the potential of construction methods with higher densities, a comparison and evaluation were made between typical solid constructions in bulk density classes ranging from 600 kg/m³ to 1800 kg/m³ and lightweight construction (Timber). Over the past few decades, there has been a significant shift in building construction practices, particularly in the design of the building envelope. Consequently, achieving the associated regulations required the use of external wall constructions with lower U-values (heat transfer coefficients) and reduced densities or additional insulation layers.

As a result of changing conditions, the available thermal mass that can be activated in the event of overheating during hot summers may now be reduced, and other material properties such as load-bearing capacity and sound insulation may also change. Through examples of residential buildings with similar structures, the potential effects under future climatic conditions are illustrated. Typical modern solid external wall constructions in bulk density classes from 600 kg/m³ to 1800 kg/m³ were compared with lightweight constructions (Timber).

After sun protection devices and the proportion of window area, the thermal mass plays the third most important role in preventing overheating. In addition, solid construction methods—especially during warmer summers in the future—offer greater flexibility in facade design, as slightly larger window areas can be implemented even without sun protection.

The use of construction methods with lower densities of the outer walls means that less available thermal mass in the event of overheating in hot summers. This effect will increase significantly with corresponding warmer climates