Accessory Dwelling Unit (ADU) architecture refers to the design and construction of secondary housing units on a single residential lot. ADUs are typically smaller than the main home and serve various functions such as housing for extended family, a rental opportunity, or space for a home office. Architecturally, ADUs must efficiently use limited space, often resulting in innovative, compact designs that incorporate flexible interiors, multipurpose areas, and smart storage solutions. They are also subject to specific zoning laws and building codes that vary by location, influencing their design and placement. ADU architecture is increasingly popular for its potential to address housing shortages, increase property value, and provide a sustainable housing option within existing urban and suburban areas.