The firm has announced that its planning team, previously based at its Bristol office, will now work out of its Baker Street office in central London.
The 14 appointments mean that its planning team now numbers 20 chartered town planners, the firm said.
The new team will be headed up by GL Hearn’s former head of planning Stuart Baillie, who has joined as a partner.
Other new recruits, all joining the firm as partners, include former GL Hearn planning director Sarah Hiscutt; GL Hearn’s former head of planning in London and the South East, Nick Diment; and former GL Hearn planning director Chris Benham.
The other recruits, all moving from GL Hearn, are:
James Cogan – associate
James Bylina – graduate planner
Jonny Ordidge – senior planner
Kelly McCann – planner
Roland Brass - partner
Knight Frank said that the remaining five recruits would be announced at the end of November.
The firm said it "has ambitious plans to gain market share and further grow the planning division over the next three years".
Alistair Elliott, Knight Frank’s senior partner and group chairman, said: "The team we have put in place has a proven track record and strong reputation in the market.
"This is the first phase of our strategic drive to develop a market-leading residential and commercial planning business in the UK."
Planning has contacted GL Hearn for comment, but at the time of writing has yet to receive a response.