This case shows the on-site rain spray waterproof test of our foldable container house at a highland pasture in the UK. The cabin has wood-grain exterior cladding, black steel frames and large sliding glass doors. The waterproof spray test is carried out under highland pasture conditions to verify the sealing and rainproof performance of the building. It adopts a modular foldable structure with the main body fully prefabricated in the factory. On-site assembly is convenient and does not require extensive civil works. Professional sealing and waterproof treatment are applied to wall panels and joints, enabling the cabin to cope with the rainy, humid and windy temperate maritime climate of the UK. It can withstand persistent rainfall and gusty winds. When folded, the unit is compact for overland transportation in hilly areas and reduces transit costs. Water and electrical pipelines are pre-embedded inside, so the cabin can be put into service once connected after assembly. It is suitable for auxiliary ranch buildings, countryside retreat cabins and remote temporary offices in the UK. Multiple units can be connected and combined. The houses can be disassembled, relocated and reused. Jinzhong can upgrade sealing and wind-resistant configurations tailored for rainy and windy highland environments. We provide one-stop manufacturing, testing and inspection services. It is a reliable prefab building solution for rural and remote areas in Europe.