The average builder in the USA provides a warrantee for 10 years, and the US Department for Energy calculates that US office buildings have an average lifespan of 73 years. No building is permanent, and all will face demolition at some point. When a building comes to the end of its safe and useful lifespan, there is no method for re-using the material in new buildings, instead, all constructions today require virgin material. This is a problem for sustainability because US cities, like most other global cities, require cyclical replacement of ageing buildings, and therefore perpetual resource extraction. This paper provides techniques for computationally arranging materials after the demolition and unmaking of architecture. Rather than downcycling concrete into low-value aggregate or melting float glass into opaque bottles methods are shown for this material to be indexed, re-machined and algorithmically arranged into new assemblies. These assemblies are conceived of as holding patterns; an indexed library of materials that are put into useful architectural arrangements, but ready to be disassembled towards some future use. These holding patterns are used as infill to the city rather than landfill beyond. Rather than building for sixty-year life spans, the project offers an imagination of eternal re-constructions that can learn from the carcass of past buildings. Based on rough estimates  2016 could be the first year where there exists more than one trillion tons of concrete on earth. More than the total weight of living trees on the planet (Crowther et al. 2015; USGS, 2018). This paper begins to develop new aptitudes for re-fitting misfit material rather than consuming evermore.