In July 2025, Sweden passed a new building code, replacing windows and daylight with a technicallystandardised daylight factor. Newly built holiday housing in Sweden already shows signs of thisreregulation: instead of rooms, apartments feature windowless spaces of 5 sqm or less in size. This currentstate of affairs stands in contrast to the intangible concept of trevnad (loosely translated as comfort andwell-being), embedded in Swedish legislation from 1932 to 1995. Through a conceptual history analysis oflegal texts and preparatory works, this paper traces how trevnad emerged as a response to critiques ofclosed courtyards and overcrowding, was abolished amid semantic shift and historical amnesia, andultimately disembodied into supposedly neutral technical metrics. As an umbrella concept, trevnad onceanchored aesthetic and social values across scales—from urban plans to interior design—actively shapingthe built environment. Framed by Picon’s notion of architectural "ghosts", this paper invites areassessment of the qualitative values that legislation can embed.