Disclosed are various embodiments of deck drainage systems. In some embodiments, the deck drainage system includes a hanger. The hanger can include a first arm and a second arm. A fastener is configured to be inserted into an opening formed in the first arm. The second arm extends from the first arm, and the second arm forms a slot for an end section of a floor panel.

Buildings which include rudimentary plumbing can be transported as a set of disassembled modular parts and then assembled on site. The assembled building includes a water reservoir in the roof and a sewage reservoir in the base, so as to enable gravity-based water supply and sewage disposal in the absence of traditional plumbing and sewage infrastructure. Building envelope elements having internal reservoirs, and methods for constructing such building envelope elements are also described.