This is reasonable. Physically, WiFi transmission can always be dampered by higher density material, e.g. high strength AL. The ultra high frequencies (2.4 Ghz and 5 Ghz), which carries WiFi data is not able to transferred far if too much concrete walls. PS: - Density of concrete: 2320 kg/m³ - Density of AL: 2700 kg/m³ Although the thickness of the barrier material plays a big role, the distance of the receiver (WiFi card) to the casing plays a even bigger role. Since the Al casing always covers the Laptop body very closely, the insulation of WiFi would be more significant. Anyway, my thoughts above need an electro-engineer to verify.