Eco-friendly Prefabricated Structures Prafabric / Modular structure is frequently recommended for energy efficiency and sustainable construction. Traditional construction methods require extra materials that lead to waste increase. However, since prefabricated subassemblies are done in a factory, additional materials can be recycled within the company. This is an important improvement in sending waste directly from a traditional construction site to a landfill. In addition, the controlled environment of a factory allows for a better structure, tighter connections and better air filtration; this provides better wall insulation and increases energy efficiency.