Spencer and Clinton McCarthy, joint managing directors of Emlor Homes, have set a bullish target for Emlor Retirement Homes: 25% of the retirement sector in the next five years. McCarthy & Stone currently has a 75% share.
Spencer said he believed this was achievable because McCarthy & Stone did not have any real competition. He said: "McCarthy & Stone have had it easy. But we are going to have an impact."
He stressed that his father, set to take a back seat at McCarthy & Stone from the end of the year, will have no formal involvement in Emlor Retirement Homes.
"He will be watching us with interest, as I'm sure many other people are, but he has only offered sound advice," he said.
Spencer said several senior members of McCarthy & Stone's staff have left to join Emlor, which has a turnover of £7m and has so far specialised in out-of-town executive homes. "They came to us. We are a smaller company, with fewer decision-makers, and can move a lot faster."
Spencer acknowledged that his experience in the sector, gained while working at his father's firm before leaving to set up Emlor Homes with Clinton in 1994, would also be useful.
Spencer said Emlor Retirement Homes' focus on the sheltered housing market would give it an advantage over other companies competing in the sector.
"Other firms have had their fingers burned because their business was focused elsewhere.
But ours will be focused on sheltered housing," he said.
"The future is in housing for an ageing population. The margins are very good, which at the end of the day is what we are in business for. It makes economic sense."
Emlor Homes will shift its building emphasis to 80% retirement housing and 20% executive homes within the next five years. Work will start on up to 100 units by the end of the year.
Permission to build has been secured for three brownfield sites in south-east England and is expected to be granted shortly on a fourth.
John McCarthy was unavailable for comment.