Flat top expansion container house, also known as flat top double wing expansion box or flat top expandable container house, is a high-end modular assembly building product optimized and upgraded on the basis of standard expansion box. This product deeply integrates the two core technologies of "flat top design" and "double wing expansion", using standard containers or light steel structures as the basic framework to maintain a compact folding size during transportation. After arriving at the site, it is unfolded to both sides through hinges or hydraulic systems, instantly expanding the indoor usable area to 2-3 times the original transportation size.

Unlike traditional sloping expansion boxes, flat top expansion container houses adopt a full flat roof structure, which not only retains the spatial conversion ability of the expansion box for "folding transportation and unfolding living", but also achieves qualitative improvements in architectural aesthetics, functional expansion, structural stability, and other aspects. The flat top design abandons the traditional central raised roof and has a simpler and more modern appearance, which can perfectly integrate into diverse environments such as urban, rural, cultural and tourism. The fully flat roof structure facilitates subsequent upgrades and renovations, and also provides an ideal platform for installing additional facilities such as rooftop gardens, solar panels, communication equipment, water tanks, etc