Quantifying Typological Repetition, Compactness, and Domestic Spatial Quality in Finnish Apartment Layouts: Evidence from Aurinkolahti, Helsinki

Apartment floor plans have traditionally been interpreted through qualitative typological readings, but coded floor-plan datasets now enable reproducible quantitative analysis. This article examines architectural metadata from apartment units in Aurinkolahti, Helsinki, Finland, to explore typological repetition, spatial compactness, and selected indicators of domestic spatial quality. Rather than reconstructing full apartment geometries, the study treats each mapped layout as an architectural metadata record and distinguishes it from the number of built apartments represented by that layout. This stock-sensitive distinction allows repeated floor plans to be analyzed as components of housing production, not merely as individual cases. The workflow includes data cleaning, classification-coverage assessment, weighted and unweighted summaries, temporal grouping, compactness metrics, repetition indicators, kitchen-related quality markers, exploratory clustering, and statistical modeling. Results show typological concentration around a limited number of layout families and identify the 2021–2023 period as combining smaller weighted mean floor areas, higher repetition intensity, and lower kitchen natural-light shares. Coded floor-plan metadata are therefore positioned as a limited but useful intermediate form of architectural evidence: more structured than visual typological description, but not a substitute for direct plan analysis or comprehensive housing-quality assessment.