This lecture introduces the basic aesthetic principles of High-Tech architecture, focusing on how buildings express technology, structure, and services as integral elements of design. It explains concepts such as the “inside-out” approach, where structural systems and building services are exposed externally, and Bowellism, which turns mechanical and service elements into architectural expression. Through examples like the Centre Pompidou, Lloyd’s Building, and the Inmos Factory, the lecture demonstrates how High-Tech architecture celebrates the construction process, achieves column-free flexible interiors, and emphasizes transparency, layering of building systems, and visual movement. It also discusses the functional logic, technological optimism, and criticisms associated with this architectural approach.