General

In developing fictional environments and settings, there comes an opportunity to approach it through applying architecture knowledge. Though speculating is a core part of the design process in architecture, the field of Speculative Architecture is not one of popularity.

Below are a few things gathered around the definition of speculative architecture:

The term “architecture fiction” is known to have been coined by writer Bruce Sterling in 2006, in referring to an architect’s speculative projects that are more alike self-expression through visual storytelling that concern the built environment.

Narrative driven projects and storytelling through architecture. Seeing as the design processes in the field also call for the ability to present, explore, and synthesize complex ideas.

Fictional architecture is the imagination and visual realization of unbuilt structures, dwellings, and urban environments. Operating between art and architecture as it gives opportunity to ponder architectural possibilities without bounds.

Speculative designs may offer visionary directions forward.

“Their subversive work guides our collective move forward, not by indicating an ideal destination, but rather by offering directions along the way.”
source: https://www.architectural-review.com/essays/speculative-design-playing-devils-advocate/8659931.article

Archigram

Archigram seems to be one of the more known example of speculative architecture, since the newsletter and illustrations that were created are mostly just radical ideas and fictional instead of being an actual built environment.

Avant-garde architectural group based in London that incorporated pop culture and advertising, new technology and neo-futurist imagery in the late 1960s. The group came about to criticize projects, write letters to the architectural press, and help each other in projects and competitions in an attempt to keep each other from the boredom of post-war London firms.
Their newsletter, which was illustrations of radical architecture ideas, were meant to re-evaluate architectural practices and it’s nature at the time. Their illustrations were made used theories of modern architecture such as Futurism, Constructivism, and Brutalism
It has been noted that due to its unfettered creativity, Archigram was usually enjoyed more by artists since most architects of the time dismissed it as fantastical.
But looking back at Modern British architecture, Archigram played a part in practicing the Brutalist style of architecture and inspired more structural and functionalist expressionism in buildings. This helped spark the more futuristic High-Tech architecture that started at the end of British 20^th Century architecture.