Household water consumption patterns revealed through high-resolution fixture-level monitoring in a Swedish living lab

Detailed knowledge of household water use, at the level of individual fixtures, at high time resolution and in shared housing, remains scarce, limiting the design of water- and energy-efficient buildings. This study draws on a rare three-year dataset from the HSB Living Lab, a purpose-built residential facility in Gothenburg, Sweden combining two housing typologies: communal shared-living clusters and conventional self-contained apartments. Every fixture was metered individually by 214 m at 1-litre resolution and a fixed 10-min reporting interval, with hot and cold supply lines metered separately, allowing consumption to be characterised from 10 min to three years, decomposed by end use and compared between housing types within one building, climate and metering system. Residential consumption was 94–110 L/person/day, below the Swedish average of 140. Showers were the largest end use (30.5%); 38.3% of residential water and 64.4% of shower water were hot. The building's most distinctive features, a high shared-space share and a late-evening peak, proved specific to the communal clusters, whereas the conventional apartments behaved much like mainstream housing, clarifying which findings transfer beyond student living. Three results apply directly to water–energy management: peak-demand factors for system sizing (peak hour factor 1.53; daily peak-to-mean 4.40, or 2.49 on a 99th-percentile-day basis); a ranking of end uses by coupled water–energy intensity identifying showers as the highest-leverage retrofit target, where a low-flow measure would save an estimated 110 m 3 of water and 3900 kW h per year; and evidence that hybrid metering and billing suits shared housing, where much consumption is collective.