EPS

The story

Dismissed by architects, trusted by engineers. The case for taking EPS seriously.

EPS has an image problem. Because it is inexpensive and widely available, it is often assumed to be low-quality. The reality is more nuanced. Expanded polystyrene has been used in insulated building construction for over 50 years, and its real-world durability record in temperate and dry climates is exceptional. It does not absorb moisture under normal conditions, it does not creep under sustained load, and it maintains its rated thermal performance over the life of the building. For projects in commercial and modular construction where budgets are fixed and performance requirements are moderate, EPS is not a compromise — it is the economically rational choice. Royal Havilah specifies EPS at a density range of 15–25 kg/m³ because this is where the optimal balance between thermal performance and compressive strength lies. Going lower reduces cost further but creates long-term settlement risk. We do not offer that grade.