Solar Rooms & Additions is a specialized industry within the General Contractors-Single-Family Houses subdivision of SIC Code 1521. This industry involves the construction of additional rooms or entire structures that are designed to maximize the use of solar energy. Solar Rooms & Additions are built with the intention of reducing energy consumption and promoting sustainability. These structures are typically built with large windows and skylights to allow for natural light and heat to enter the space. The industry requires a high level of expertise in solar technology and construction techniques to ensure that the structures are energy-efficient and structurally sound.