At least 150 apartments and houses are likely to be built on the site of the late Tom Roche's home on Cross Avenue in south County Dublin

The family of the late Mr Tom Roche, co-founder of Roadstone, is to share around €45 million from the sale of their large period home on almost nine acres at Cross Avenue in Blackrock, Co Dublin. It is the second highest price paid for a house and grounds in south Dublin. Last December, Ballinteer Hall on 24 acres in Rathfarnham made €51 million.

The Blackrock property has been acquired by a little-known developer, Mr Myles Crofton of Naus Developments, who is expected to seek planning permission for at least 150 apartments and houses in the heavily wooded grounds.

Although the big rambling house, Chesterfield, and its grounds were expected to come on the market at some stage following Mr Roche's death in 1999 (he was pre-deceased by his wife in 1996), most of the leading housebuilders will be surprised that the property has been sold privately.

Agent DTZ Sherry FitzGerald handled the confidential negotiations between Mr Crofton and Mr Tom Roche, junior, who is expected to benefit from the sale along with his three sisters, Maura, Eleanor and Claire. Mr Roche is married to Ann Doyle, daughter of the late hotelier PV Doyle.

Conor O'Gallagher of Sherry FitzGerald New Homes said yesterday that he was not in a position to comment at this stage.

Chesterfield has been home to the Roche family for over 40 years and was previously owned by another Dublin business family, the Bradburys. It is one of the last private homes in Blackrock with extensive grounds. It has considerable frontage onto Cross Avenue and also adjoins several other housing developments including Booterstown Park and Cherbury Gardens on one side and Glenvar Park and South Wood Park on the opposite side.

In July 1995, a large Victorian house, Clonfadda, on 7.5 acres at the rear of Chesterfield and with frontage on to Mount Merrion Avenue, was sold at auction for £3.9 million (€4.953 million). The successful bidders, Gem Construction, later built 40 two and three-bedroom apartments in the grounds along with 25 houses which were sold from plans for between £217,000 (€275,590) and £315,000 (€400,050). One of the five-bedroom detached houses recently sold at auction for €1,735,000.

Mr Crofton has been quietly building houses over the past two decades and is currently developing Ashbourne Town Centre and several hundred apartments in Co Meath's second largest town.

While the sale of Chesterfield is subject to a confidentiality agreement between the Roche family and Mr Crofton, it is thought likely that he will seek planning permission for at least 100 large homes which would be expected to sell for more than €2 million each. With State policy now favouring high density developments on suitable sites, the new owner of Chesterfield will also be hoping to get approval for a considerable number of apartments, which would be much sought after in the Blackrock area where there have been few new developments in recent years. Good-sized, two-bedroom apartments would fetch up to €1 million each in such a prime leafy location.

Mr Roche, who died in July 1999 at the age of 83, was one of the most successful Dublin businessmen in the last century. When his father, a civil servant,died in 1932 his family was left with little more than personal savings and moved from Sandymount to Inchicore. With the savings, his mother Kathleen bought a sweet shop for £250.

Tom Roche subsequently purchased a small coal and sand business for £800 and even before he was 16 he found himself running the business with three employees and a 1.5 ton truck.

In 1944 he established a gravel business called Castle Sand Company; he was managing director and his brother Donal was his assistant. In 1949, the company went public as Roadstone.

He will be best remembered for his audacious move to take over the gilt-edged Cement group in 1970. The move succeeded even though Roadstone did not have sufficient funds to mount such a bid for the cash rich cement company. Roadstone offered shares instead. In more recent years, Mr Roche founded National Toll Roads, the company that owns the East-Link and WestLink toll bridges.