The Hidden 'Building Drift' That Dooms Reclaimed Construction — And the Tool That Finally Tracks It

A team led by Ritik Batra and colleagues from institutions like ITU Copenhagen and Cornell University published a paper introducing 'building drift'—the collective deviation of a building's physical state from its digital model due to on-site improvisation with reclaimed materials. In a circular economy, these materials come with unpredictable histories, forcing builders to adapt on the fly. Without documentation, these adaptations are lost, hindering future reuse. The researchers developed a taxonomy of five drift categories observed during the construction of ReShelter, a reclaimed timber pavilion: Tending the Site, Foraging for Fit, Interpreting the Material, Marking Measurements, and Coordinating Across Communities.

To operationalize this framework, they created Pentimento, a documentation tool that leverages video recordings and 3D Gaussian Splatting—a technique that reconstructs scenes from multiple images—to capture adaptations in spatial, temporal, and semantic context relative to the original design. Pentimento allows stakeholders (architects, builders, future recyclers) to navigate material histories and understand why deviations occurred. This enables more informed reuse decisions, reducing waste and supporting sustainable construction cycles. The work opens pathways for computational tools that embrace unpredictability rather than trying to eliminate it.