Plans to develop new housing on the grounds of the most expensive house in the country, at Shrewsbury Road in Ballsbridge, Dublin 4, have been ruled invalid because the applicant did not comply with provisions for social and affordable housing.

A letter that was supposed to have been submitted with the application in relation to social and affordable housing could not be found.

The owners of Walford, which sold for €58m in 2006, were told that they had underpaid fees by €80 and that €699 was now due when a new permission was sought. They were also told that the description of plans for the site were "insufficient for the information of the public".

Planning was sought to extend the house to more than double its size, and to build nine detached houses to the rear. The planning permission was sought by a vehicle called Matsack Nominees.

Developer Sean Dunne has been linked to the building but he has always insisted that he does not own it and has no interest in it.

Walford is a Tudor-style detached home on 1.8 acres and was sold by the family of the late Patrick Duggan, who was involved in banking and insurance and had owned it since 1954. It had been expected to sell for about €35m but demand sent the price soaring and eventually it sold for €58m even though that there was a boundary dispute with a neighbour.