Count a reuse observation as one occupied room on one date, checked once that day. The same room may be observed again on another date, but only once on the same date. That is not a count of distinct rooms or distinct stays. Write how many opportunities were eligible, how many were checked, and how many were unknown. Uninspected rooms are unknown coverage, not non-participation. Laundry kilograms stay in a separate column. There is no water or energy cell.

Return to the hospitality overview for the linen-reuse line. Occupied room-nights as a ratio denominator stay on the hotel KPI sheet. Before a public reuse claim, use the green-claims guide.

What a reuse observation is

The observation unit on this sheet is room_night_service.

Eligible opportunities are occupied room-nights where reuse could have been offered. Checked opportunities are those actually inspected. Whole counts obey 0 <= reuse_observations <= checked_opportunities <= eligible_opportunities <= occupied_room_nights. When eligible and checked counts are both known, unknown coverage is eligible minus checked. Missing inputs stay missing; they are not stored as zero or as non-participation. Impossible or negative counts cannot be complete. reuse_observations is the number of checked room-nights where staff recorded that at least one towel was left for reuse.

Laundry is items or kilograms from a laundry note, with its own coverage. The two figures are not subtracted. If occupied room-nights are blank or zero, no rate is written.

Goldstein, Cialdini and Griskevicius, Journal of Consumer Research, 3 March 2008, measured whether guests reused at least one towel in a hotel in the south-western United States. Their participation rates are not a target here. Occupied room-nights on this sheet are not a replica of that study’s sampling design. The paper does not report a litre or kilowatt-hour saving for that observation.

The Hotel Carbon Measurement Initiative introduction allows outsourced laundry to be estimated from occupied rooms when contractor energy and laundry tonnage are unavailable. This sheet does not make that estimate.

Fill in one row per period

Download both files. Save a copy of the blank file and type into that copy.

The files are plain CSV. They do not divide participation by rooms, subtract two weeks, or store a litre.

comparison_basis is the laundry measurement method: how the kilograms or items were obtained, for which items, and over which collection. A complete row needs a positive occupied-room count, eligible and checked counts, unknown coverage equal to eligible minus checked when those counts are known, reuse observations that do not exceed checked opportunities, a laundry quantity with its unit, source and coverage, and a written comparison_basis. Blank checked opportunities are unknown_coverage. A comparison is possible only when two complete rows share the number of days, the room set, the item scope, the laundry unit, the laundry coverage and comparison_basis. Differing occupancy must be written in occupancy_note. Raw laundry totals still do not establish an effect caused by reuse.

Worked example: 40 room-night observations and 80 kg, kept apart

The rows are fictional weeks at Northgate Rooms, a 20-room hotel that is invented. Every row uses room_night_service.

Period What was written Status
1 to 7 March 2026 100 occupied room-nights, 100 eligible, 90 checked, 10 unknown, 40 reuse observations, 80 kg from laundry note LN-031 for the same rooms and towels. Method: contractor weighbridge, towels only, same 7-day collection. Complete. 0 <= 40 <= 90 <= 100 <= 100. The 40 are room-night checks, not 40 distinct rooms. The 10 uninspected room-nights are unknown coverage, not non-participation. The 40 and the 80 kg stay apart.
8 to 14 March 2026 80 occupied room-nights. Occupancy differed. Checked opportunities blank. 70 kg on the laundry note. Unknown coverage. Not compared. Uninspected rooms are not treated as non-participation.
1 to 7 March 2026, water note A note that says 50 litres saved. Excluded saving. The quantity stays blank.

Limits

A complete row does not show that water or energy use fell. Before a public reuse claim, use the green-claims guide.

Sources