The accreditation, based on customer feedback results from April 2014 to March 2015, is testament to the venues' ongoing dedication to providing exceptional customer service.
BDRC Continental obtained feedback from around 375 participating meeting venues and hotels in the UK and Ireland. Highgate House, Woodside and Barnett Hill are amongst 36 venues that have achieved the Gold Standard accreditation.
Sundial Group's Managing Director, Tim Chudley, said: "Once again, we are delighted to have received the prestigious Gold Standard accreditation for all Sundial venues. This accreditation is always very rewarding as it is the result of feedback from our customers. It also reflects the commitment of everyone at our venues who always strive to make sure every guest has a positive customer experience."