Transport Minister Leo Varadkar has apologised for the confusion caused by the Government's handling of the water charges issue.
He said people are struggling with bills and the cost of living is increasing and nobody in Government wanted to scare people.
Speaking on RTÉ's The Week in Politics programme he said the charges will not "come into play" for more than two years.
The minister admitted that about 20% of older houses and apartments cannot be metered.
He suggested the charge could be estimated based on the size of the house and the number of people living there.
The minister added the exact detail would have to be worked out by Government at a later stage.