The first phase of a multi-million dollar upgrade to the main grandstand at Rosehill Racecourse has begun with some temporary measures in place while the work is being carried out.

From this Saturday, members and general admission racegoers will be serviced by separate betting rings with the first stage on the new indoor ring already underway.

A temporary public betting ring with the same number of on-course bookmakers as at all Saturday meetings as well as new TAB facilities, will be inside the ground level of the J R Fleming Grandstand.

Members will be served by another betting ring inside the Grand Pavilion.

The refurbishment which includes modernised bars and restaurants on all levels, new access and walkways to outdoor seating, is planned in three stages over the next 12 months.

Australian Turf Club chief executive Darren Pearce said the start of work marked an exciting period for the Rosehill Racecourse with the developments financed by the balance of the grant from the state government following the merger of the Australian Jockey Club and the Sydney Turf Club.