Fixeddome

Fixeddome is a term used in architecture and structural engineering to describe a dome whose geometric form is fixed at construction and is not intended to be reconfigured or deployed. In this usage, fixed contrasts with deployable, inflatable, or retractable dome systems. A fixeddome typically employs a rigid shell, often built from triangulated facets such as a geodesic or polyhedral dome, or from curved surface shells fashioned from reinforced concrete, steel, or composite materials. The fixed geometry provides predictable load paths, enabling straightforward analysis for wind, snow, and seismic forces, and generally results in a durable, long‑lasting enclosure.

Design considerations for fixeddomes include shell thickness, joint detailing, thermal performance, and maintenance access. Because the shell is non‑retractable, fixeddomes tend to be heavier and more expensive per square meter than lightweight deployable alternatives, but they offer higher stiffness and can accommodate larger spans with standard construction methods. Aesthetically, fixeddomes can provide distinctive skylight opportunities or dramatic interior volumes, contributing to their use in prominent cultural or civic buildings.

Use cases are common in permanent facilities such as religious buildings, museums, planetariums, or sports venues where a durable, architecturally distinctive roof is desired. The term is not universally standard in architectural lexicons, and some professionals may simply refer to fixed-shell domes without using the label fixeddome.

See also: dome, geodesic dome, shell structure, deployable structure.