How does curtain wall thermal performance compare to a window wall system?

The thermal performance of a curtain wall system is generally superior to that of a traditional window wall, a critical distinction for buildings in the extreme climate of the Middle East. A curtain wall is an exterior, non-structural cladding system that hangs from the building's floor slabs, creating a continuous and uninterrupted thermal envelope. High-performance curtain walls utilize thermally broken aluminum frames, where a material with low thermal conductivity is placed between the interior and exterior aluminum profiles. This "thermal break" effectively stops the flow of heat, preventing the intense summer heat of cities like Jeddah from penetrating the building's interior and stopping cooled air from escaping. Combined with high-performance double or triple glazing with Low-E coatings, this system significantly reduces thermal bridging and enhances overall energy efficiency. Conversely, a window wall system consists of smaller, individual window units that are installed between the floor slabs of a building. This "slab-to-slab" installation creates a major source of thermal bridging at every floor line, as the concrete slab is often exposed or poorly insulated at the building's edge. This inherent discontinuity in the building envelope allows for significant heat transfer, leading to higher energy consumption for cooling and potential condensation issues. For developers aiming to meet the sustainability goals of Saudi Vision 2030, the superior, continuous thermal envelope provided by a well-designed aluminum curtain wall is essential for creating comfortable, energy-efficient buildings that can withstand the demanding local climate.