The construction industry ranks among the most resource-intensive and environmentally impactful sectors worldwide. It accounts for approximately 40% of energy consumption, one-third of water use, and half of all raw materials extracted. Additionally, it is responsible for about 39% of global CO₂ emissions, with operational energy use and the embodied carbon in building materials being major contributors.

One of the key challenges is balancing the need for energy efficiency in buildings with the demands of modern construction. Spaces such as bathrooms, which require consistent indoor thermal regulations, especially in northern climates like Scandinavia, are particularly energy-intensive due to heating demands. This is becoming increasingly critical with rising electricity prices. 

To tackle these challenges, innovative materials and approaches are urgently needed, not only to reduce energy consumption during building use but also to minimize the environmental impact of materials throughout their lifecycle. At Østfold University College (HIOF), the Advanced Materials Group has taken a role in addressing these issues through the EU-funded SNUG project.

In Scandinavian countries, heated floors are quite common. The floor heating system (electric or circulating water) is normally covered by a layer of self-leveling mortar. To improve these systems, one of the solutions under development at HIOF is a self-leveling mortar enhanced with phase change materials (PCM).

PCMs are advanced materials that can absorb and release thermal energy during phase transitions, typically between solid and liquid states. This material can help regulate indoor temperatures by storing heat when the heat source is turned on and gradually releasing it when the heat source is turned off. In this way, we can utilize cheap energy in off-peak periods. In high peak periods, when the electricity is expensive, the heating system can be turned off, and the PCMs will release heat to keep the floor warm.

However, designing such a material comes with its challenges, including ensuring that the PCM-enhanced mortar maintains its flowability, structural integrity, and long-term durability.