Anthony Longman of Skyframe Research presented his concept for a free space settlement built from Asteroid materials at the Space Studies Institute SSI 50 last September. The system uses a structural design concept called Tensegrity to start small from an 8.5m pressure hull and expand iteratively to progressively larger stages ending with a habitat large enough for 8000 people. The final structure contains 90 acres of managed woodland complete with outdoor mall space and over 5 floors of living quarters. Longman appeared recently on The Space Show to provide further details of the concept. His presentation can be found at timestamp 1:32 into the SSI 50: 01 Habitat Design Presentation.
Cutting-edge technology enabling settlement of the solar system and beyond – Art by Rick Guidice / NASA