Why did smaller mid-20th-century homes encourage built-in furniture?

In the context of mid-20th-century interior design, the shift toward built-in furniture was primarily driven by the need to maximize efficiency in increasingly smaller homes. As architects and designers embraced Functionalism, convenience and economy became central considerations in how living spaces were organized.1

The adoption of built-in units served several practical purposes:

• Space Optimization: Because living areas often served multiple purposes and were frequently irregular in plan, keeping movable furniture to a minimum was essential to maintain functionality and flow.1
• Efficiency: Designers sought to eliminate formal barriers and traditional room divisions. By integrating utility units directly into the living space rather than hiding them in unused areas, they created a more efficient "machine for living".1
• Aesthetic Simplicity: Built-in furniture allowed for a cleaner look by adhering to the movement's insistence on simplicity of form, color, and texture, ensuring that necessary equipment obtruded as little as possible.1

This approach helped manage the spatial constraints of the era while supporting the modern desire for open, flexible, and uncluttered interiors.1