: The oldest architectural concept, demarcating private from public and focusing on protection.

Contemporary architectural theory, notably discussed in works like Randall Korman's The Architecture of the Facade , categorizes facades into three primary types:

: Modern designs prioritize energy-efficient materials like ACP (Aluminium Composite Panels) and smart glass to reduce environmental impact.

I. Introduction: The Facade as Interface

: Focused on structural requirements, environmental efficiency (e.g., double-skin facades), or purely internal program functions.

: Designed as communicative surfaces that act as public-facing messages or "canvases" for the city. IV. The "Skin" vs. The "Envelope"

While often used interchangeably, these terms represent different conceptual approaches:

: This controversial practice involves preserving the historic exterior of a building while completely rebuilding its interior—a compromise between preservation and economic necessity. VI. Conclusion: The Future of Dynamic Envelopes