She puts their success down to a number of things.
"I know it's about being friendly and welcoming but we're also pretty laid back here and our staff work hard to keep the complex the way it is," she said.
"It's really about providing good service and going the extra mile for our customers."
Ms Frew and Mr Gill took over the lease in 2010, a year after 151 on London opened.
The Corporate Events Guide people's choice award recognises Kiwi companies that have excelled in their field of expertise over the last 12 months.
Now in their fourth year, the people's choice awards have become the most prestigious awards in the event planning industry, are voted by the public and directly relate to the quality of service.