The Tring-based company completed the purchase of the freehold of the pub for £1.6m and is now planning a £1.4m refurb before it reopens with a restaurant, two bars and 19 boutique bedrooms.
Peter Borg-Neal, the hospitality entrepreneur who founded the company in 2007, said the acquisition was the first of a number of new properties as the now six-strong group looks to expand.
"With respect to our buildings, The Crown and Thistle is a tremendous addition to our collection. It has taken us nearly a year to bring this deal to fruition and I am delighted to finally get it over the line. We are also in advanced discussion regarding a couple more sites and hope to be able to make further announcements shortly."
The chief executive said Oakman's expansion plans had come about after a strong start to the financial year which have seen each of its five sites average sales of just under £31k in the 18 weeks to 5 August - representing like-for-like sales growth in the period of 21.52 per cent.
"It is a reward for the tremendous passion and hard work of our people. Trading conditions will remain difficult and we will look to constantly evolve our ability to please our customers. To us it is about three core pillars: great people, great buildings and a great concept."
The British Larder
In order to focus on the growth of its core estate, Oakman Inns has revealed it plans to sell its stake in The British Larder business which operates the website and Suffolk pub of the same name.
"We are very proud to have helped Ross Pike and Madalene Bonvini-Hamel realise their dreams by creating this wonderful business over the past two and a half years. However, they need partners who are properly focused on The British Larder and with the expansion of Oakman Inns this is becoming hard for us," Borg-Neal said.
He revealed several interested parties were in discussions about purchasing the stake to help The British Larder raise expansion capital while the business will be run independently of Oakman Inns in the meantime.