What if I don’t have a water meter—how do I estimate water consumption?

For many small and growing businesses (SMEs), water is not tracked directly with a meter. You may work from a shared office, a co-working space, or a rented building where water use is bundled into rent. Yet under the Corporate Sustainability Reporting Directive (CSRD) and the Voluntary Sustainability Reporting Standard for SMEs (VSME), you may be asked to provide water usage data.

The good news: you can estimate your water consumption using simple methods, and this is accepted practice under VSME reporting guidance.

Step 1: Start with utility bills (if available)

Even if you don’t have a separate meter, your landlord or building manager may hold the overall building water bill. This is the best starting point. Once you know the building total, you can work out your business’s share based on:

• Number of employees — divide the building’s total water use by the number of employees working there, then multiply by your own workforce size.
• Floor space — divide by square metres, then multiply by the space you rent.

This provides a fair allocation of water use when you can’t measure it directly.

Step 1a: What to Do if You Share a Building

Landlord bill allocation is the most common real-world water problem for small businesses. If your landlord holds the overall water bill and won’t share it — or shares only a total without a breakdown — here are the options:

1. Request the annual water bill total in writing. Even if your landlord declines to share a copy, they are often willing to confirm a total figure. Use this to calculate your proportionate share by floor space or headcount.
2. Use your lease to determine floor space share. If you occupy 30% of a building, estimate 30% of the building’s water use as yours.
3. Escalate through your local tenancy or commercial lease authority if you need the data for regulatory reporting and your landlord refuses. In most EU jurisdictions, tenants have a right to request utility information relevant to compliance obligations.
4. Use the employee-based estimate in Step 2 as a fallback and document that you were unable to access building-level data despite reasonable attempts.

Always note in your VSME disclosure whether data came from actual bills or an allocation estimate — transparency is more important than precision.

Step 2: Use employee-based estimates

If no bill is available, you can use average daily water use per employee. A common benchmark is 40–60 litres per employee per day for office settings (covering toilets, handwashing, tea/coffee, cleaning). For more detailed water measurement guidance, see how to measure business water usage.

Formula: Annual water use (litres) = Employees × Average litres per day × Working days per year

Example: A company with 15 employees, working 220 days per year, at 50 litres per person per day: 15 × 50 × 220 = 165,000 litres (165 m³)

Benchmarks by Industry Type

The 40–60 litres per person per day figure applies to office settings, but water use varies significantly by sector. Use the table below to choose a benchmark appropriate for your business type:

For hospitality and food service businesses, calculating by number of covers or guest nights rather than employee count gives a more accurate result.

Step 3: Estimate based on fixtures and usage

For more accuracy, you can add up water use from fixtures and appliances:

• Toilets — litres per flush × flushes per day × working days
• Taps — litres per minute × estimated use per day × working days
• Dishwasher/kitchen — litres per cycle × cycles per week × weeks per year

This method is helpful if you run a café, workshop, or customer-facing space with heavier water use than a typical office.

Step 4: Note assumptions clearly

CSRD and VSME don’t expect perfection from SMEs — just transparent, reasonable estimates. Always explain how you worked out your numbers, e.g.:

“Water consumption estimated based on 15 employees, 50 litres per person per day, 220 working days.”

This makes your disclosure credible, even if you don’t have precise meter data.

Example disclosure text

In 2024, our company operated from a shared office without a dedicated water meter. Based on employee headcount (15 staff), average use of 50 litres per employee per day, and 220 working days, we estimate our annual water withdrawal at 165 m³. Nearly all water is discharged back into the system, so consumption is considered negligible.

When Is a Water Meter Worth Installing?

For most small businesses, the estimation methods above are sufficient for VSME reporting — you do not need a meter to report credibly. However, a sub-meter may be worth the investment when:

• Your water costs are significant (e.g. food production, hospitality, manufacturing). If water is a material business expense, accurate measurement often pays for itself.
• You share a building and can’t get allocation data from your landlord. A sub-meter on your own supply eliminates the uncertainty entirely.
• Your clients are requesting precise water data. As supply chain ESG demands increase, some procurement teams ask for verified rather than estimated figures.
• You want to track year-on-year improvement. Estimates make trend analysis harder; a meter makes it simple.

Typical cost of installing a sub-meter: €150–€500, depending on whether a plumber is needed and how accessible the supply pipe is. If your annual water bill (or allocated share) exceeds roughly €1,000 per year, the measurement precision a meter provides is likely to be worth the one-off installation cost.

Frequently Asked Questions

My landlord won’t share the water bill — what do I do?

Start by requesting the information in writing, citing your VSME or CSRD data collection obligations. If the landlord still declines, use the employee-based estimate from Step 2 and document in your report that you requested building-level data but it was unavailable. This is acceptable under VSME reporting guidance, which recognises that SMEs may face data gaps due to tenancy arrangements. Over time, consider installing a sub-meter on your own supply to remove the dependency.

Can I use municipality or local authority data for water estimates?

Yes, where available. Some municipalities publish per-capita or per-property water use averages for commercial premises. These can be used as a benchmark in the same way as the industry figures above. Treat them as a secondary source and note the origin in your disclosure — local authority figures are generally more representative than generic EU averages.

Do I need to report water data if my industry isn’t water-intensive?

Under the VSME Basic Module, water is included in module B6, but the level of detail required is proportionate to the significance of water to your business. If water is genuinely low-impact for your operations (a small office, for example), a simple estimated figure with a brief methodology note is sufficient. You do not need to build a detailed water management programme unless water is a material issue identified in your sustainability assessment.

Conclusion

Not having a water meter does not prevent you from meeting VSME water reporting requirements. The four-step approach in this guide — starting with utility bills, moving to employee or industry benchmarks, using fixture-based estimates where needed, and always disclosing your method — gives you a defensible, proportionate disclosure.

If estimation feels uncertain, consider whether a sub-meter is worth the one-off cost. For most small businesses, however, a well-documented estimate is all that’s needed to report credibly and move forward.

Key Terms

• Corporate Sustainability Reporting Directive (CSRD) — An EU law requiring large companies to report on environmental and social impacts. SMEs are not directly required but may be asked for CSRD-style data.
• Voluntary Sustainability Reporting Standard for SMEs (VSME) — A simplified framework to help SMEs report on sustainability topics, including water.
• Water withdrawal — The total water brought into your business (from mains, wells, etc.).
• Water consumption — Water that is not returned, often through evaporation, irrigation, or embedding in products.
• Estimation methods — Practical approaches (per employee, per square metre, or per fixture) used when direct meter data is unavailable.
• SME (Small and Medium-sized Enterprise) — A business with fewer than 250 employees, turnover under €50m, or balance sheet under €25m.