Joe Klepp is a lifelong LEGO fan who designs his own sets using a building technique mostly commonly referred to as an expansion; that’s when multiples of the same set are used to scale up from the original model.
This concept was first shown in a grand fashion with the Café Corner, released in 2007, it is still one of the most sought after original LEGO modular sets in existence.
Although the original structure was not altered, by simply adding additional floors and opposing corners, the set can be infinitely expanded.
The Café Corner in its largest form would require 4 sets at ground level to be fully 3-dimensional, and there would be no limit to the height of the building.
The real limit however is actually getting your hands on one in the first place because they are so expensive and rare.
It’s easy to see why the Café Corner was the inspiration and motivation behind all of 4CarG’s expansion sets.