An Eichler can look original from the street while carrying decades of hidden floor-plan drift. This Property Nerd field guide explains how to read roof seams, interrupted beam grids, enclosed atriums, expanded bedroom wings and converted garages—then map those changes with a 20-point Model-Drift Score and a separate documentation-confidence grade.

Not every expensive Eichler renovation preserves value. The Property Nerds® Reversibility Score evaluates whether an update is removable, architecturally compatible or permanently architecture-erasing.