APARTMENT dwellers face having to subsidise other residents within the same development once domestic water charges are introduced, it has emerged.
The situation could occur if the Government decides to install meters at the point of entry into apartment blocks and impose a combined charge based on usage.
However, if some residents refused to pay, it would push the cost up for the remaining occupants, it is understood.
The Irish Property Owner's Association admitted the issue could cause a lot of problems.
"It is clearly going to be difficult. There are going to be huge difficulties," the association told the Herald.
In England, management companies are generally responsible for collecting the charge within flat complexes.
"The most common situation is that the whole block has one meter and the management company pays for all of it.
"It is up to the management company to bill the tenants," a spokeswoman for Cambridge Water Company said.
The Department of the Environment says that apartment complexes are among the category of households which may not be metered initially due to the high cost or technical difficulty involved.
It estimates up to 300,000 units across the country would not be metered individually.
It says the energy regulator will be responsible for determining the cost for residents in schemes with shared connections.
Another option would be to impose a flat-rate levy.
Fianna Fail senator Darragh O'Brien said residents in large-scale developments could "absolutely" end up subsiding other occupants.
He told the Herald the Government does not know how it is going to deal with apartment dwellers.
"The way it has been handled so far has been atrocious," Mr O'Brien told the Herald.
Little information about how the charges will be levied has been released by the Government to date.
Taoiseach Enda Kenny refused to give details on the potential costs on householders when he was questioned in the Dail.