Hidden leaks outside homes raise landlord costs

More than half of hidden leaks affecting residential property originate outside the building, leaving responsibility with the owner and landlords rather than the water supplier.

According to an analysis of 9,000 callouts by property maintenance firm Aspect, 58% of hidden leaks occur in underground mains supply pipes beyond the property’s structure.

The firm, which works across London and the South and East of England, found that most leaks are linked to internal plumbing or heating systems.

However, in practice, its analysis points to nearly six in 10 cases starting in pipework buried under gardens, driveways or boundary lines.

Landlord leak awareness

The firm’s leak detection manager, Neil Lampton, said: “Hidden leaks outside the home are often the hardest to identify, as they develop underground with no visible signs.

“They are often mistaken for internal plumbing or heating faults, which can delay diagnosis and increase costs.”

He added: “Greater awareness of external supply pipes as a key risk area can help landlords take a more targeted and cost-effective approach to maintenance, particularly as they are responsible for them, not the water provider.”

Leaks without warning

Aspect says the leak location matters since these pipes sit out of sight, so faults can continue without any visible warning.

Tenants may not realise anything is wrong while water escapes over time.

Responsibility for those external pipes usually sits with the property owner which means landlords face the cost of both investigation and repair.

Recent case data also highlights the scale of the problem with hidden leaks being found to waste about 56 litres of water per hour.

That adds up to more than 40,000 litres each month.

Cost of leak repairs

Also, the repair costs for a leak running for a month, range from £150 to £160, though more severe cases rise above £200 to £250.

Over a year, unresolved leaks can push bills towards £2,400 to £3,000.

Tenants in metered homes may see the first signs through higher charges.

Left unresolved, issues can develop into complaints, disputes and further maintenance demands.

To help, Aspect is advising landlords to watch for sudden changes in water use, pressure drops or unexpected bills flagged by tenants.

They are also being urged to act on supplier alerts, check external pipework, and arrange specialist leak detection where needed.