Manager Richie Heap said Naylor Love began building the mezzanine studio, above the existing free weights area in the gym, last month.
The completed facility would cost "in the mid to high $200,000s", funded entirely by Alpine Health & Fitness membership revenue.
Mr Heap said gym staff were "very excited" about the new facility, something he had been waiting for "for a long time".
"We've had a single group fitness studio, whereas most other facilities have separate rooms [for RPM and other group fitness classes].
"This will enable us to cater for more members."
In RPM classes, each participant rides a stationary bike, with an instructor leading the class in different techniques, for example, sprints and hills.
As RPM's popularity has grown, so have logistical issues and constraints.
All group fitness classes were held inthe same room, so bikes had to be wheeled into position and then stored either alongthe walls of the fitness studio, or in thefoyer.
Alpine Health and Fitness at the Queenstown Events Centre began with 12 RPM bikes, and it now owns 30.
Mr Heap said the options available had been to either build a studio dedicated to RPM classes with the same number of stationary bikes, or to increase the number of bikes and continue holding classes in the group fitness room.
The new studio would allow additional RPM classes to be included in the timetable - increasing them from 15 per week to about 22.
It would also mean more classes, as well as new classes, could be added to the group fitness timetable, Mr Heap said.
