{
  "slug": "water-use-intensity",
  "title": "Water Use Intensity Calculator",
  "heading": "Water Use Intensity (WUI) Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/water-use-intensity",
  "summary": "Gallons of water per square foot or per employee, benchmarked.",
  "description": "Water use intensity normalizes total water consumption by building area or occupancy so you can compare a 20,000 sq ft office to a 200,000 sq ft one on equal footing, and track year-over-year efficiency independent of growth. This calculator takes your annual water bill volume and computes both gallons per square foot and gallons per employee, the two metrics most commonly requested in ESG questionnaires (CDP Water Security, GRESB) and LEED water-efficiency credits. Office buildings without cooling towers or process water typically run 10-20 gallons per sq ft per year; add a cooling tower, commercial kitchen, or laundry and that number climbs sharply. Tracking this over time is how facilities teams catch leaks — a WUI that jumps 20% without a corresponding occupancy change is usually a leak or fixture failure, not a real usage increase.",
  "formula": "WUI (per area) = annual gallons ÷ square footage. WUI (per person) = annual gallons ÷ average headcount.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=water-use-intensity",
  "inputs": [
    {
      "id": "gallons",
      "label": "Annual water use",
      "kind": "number",
      "hint": null,
      "default": 1200000,
      "unit": "gallons",
      "min": 0,
      "max": null
    },
    {
      "id": "sqft",
      "label": "Building square footage",
      "kind": "number",
      "hint": null,
      "default": 60000,
      "unit": "sq ft",
      "min": 1,
      "max": null
    },
    {
      "id": "employees",
      "label": "Average headcount",
      "kind": "number",
      "hint": null,
      "default": 220,
      "unit": null,
      "min": 1,
      "max": null
    },
    {
      "id": "waterCost",
      "label": "Cost per 1,000 gallons (water + sewer)",
      "kind": "number",
      "hint": null,
      "default": 9.5,
      "unit": "$",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "perSqft",
      "label": "Gallons per sq ft / year",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "perEmployee",
      "label": "Gallons per employee / year",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "annualCost",
      "label": "Annual water + sewer cost",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "gallonsPerDay",
      "label": "Average gallons per day",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Annual water use: 1200000 gallons",
      "Building square footage: 60000 sq ft",
      "Average headcount: 220",
      "Cost per 1,000 gallons (water + sewer): 9.5 $"
    ],
    "outputs": [
      "Gallons per sq ft / year: 20",
      "Gallons per employee / year: 5,455",
      "Annual water + sewer cost: $11,400",
      "Average gallons per day: 3,288"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter annual water use (gallons).",
      "Enter building square footage (sq ft).",
      "Enter average headcount.",
      "Enter cost per 1,000 gallons (water + sewer) ($).",
      "Read your gallons per sq ft / year on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "gallons": 720000,
        "sqft": 36000,
        "employees": 130,
        "waterCost": 5.7
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "gallons": 1200000,
        "sqft": 60000,
        "employees": 220,
        "waterCost": 9.5
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "gallons": 1920000,
        "sqft": 96000,
        "employees": 350,
        "waterCost": 15.200000000000001
      }
    }
  ],
  "limitations": [
    "Estimates assume standard, average conditions — local rules, pricing, and materials vary.",
    "Results are rounded for readability; add a buffer before ordering, booking, or committing.",
    "Double-check anything with a real cost attached against a local quote."
  ],
  "faq": [
    {
      "q": "What's a good WUI benchmark for an office building?",
      "a": "A typical US office without cooling towers runs 10-20 gallons per sq ft per year, dominated by restroom fixtures and kitchen use. Buildings with evaporative cooling towers can see this double or triple because cooling towers consume water continuously through evaporation and blowdown."
    },
    {
      "q": "How do I use this for CDP Water Security disclosure?",
      "a": "CDP asks for total water withdrawal and consumption, often normalized by revenue or floor area. Reporting gallons per sq ft alongside your absolute volume gives reviewers the intensity trend they're looking for, and it's the same metric LEED v4 Water Efficiency credits use for baseline comparison."
    },
    {
      "q": "My WUI jumped significantly year over year — what should I check first?",
      "a": "Check for running toilets and irrigation controller failures first — these are the two most common causes of unexplained spikes and are usually invisible until the bill arrives. A submeter on major fixture groups (restrooms, kitchen, irrigation, cooling tower) makes root-causing this much faster than working from one aggregate number."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/water-fixture-retrofit-savings",
    "https://www.revenuelab.fyi/toolbox/building-eui",
    "https://www.revenuelab.fyi/toolbox/scope1-2-emissions"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Water Use Intensity Calculator (https://www.revenuelab.fyi/toolbox/water-use-intensity)"
}