Start with like-for-like readings
Use readings over comparable periods. Check whether a bill is based on an estimate and note changes in occupancy, laundry and kitchen activity. Share the figures with the person responsible for utilities.
Account for continuous uses
Toilets, equipment and planned overnight activity can all use water. An engineer needs that context before interpreting flow. Do not turn off essential supplies as an informal test.
Give ADI the evidence you have
Send recent readings, the site postcode and a summary of the change. The team can discuss whether a mains investigation is appropriate and what access to the meter and supply will be needed.
Service information: ADI’s commercial leak detection service. Content reviewed September 2026. Confirm the scope and site arrangements directly with ADI.