The Randwick Guineas will be switched to Warwick Farm next year but the Australian Turf Club will stage the track's remaining Group One races at headquarters.

Darren Pearce, chief executive of the ATC, said the decision had been made to allow builders working on the reconstruction of Randwick an extra month to complete as much of the new grandstand as possible.

"The priority ahead of the BMW Sydney carnival is to give construction company Brookfield Multiplex an unimpeded run to complete as much as possible ahead of David Jones Australian Derby Day at Royal Randwick on 13 April," Pearce said in a statement.

The Guineas, run on March 16 next year, will be the first Randwick Group One event not held at the venue since the redevelopment began at the end of last year.

Around 60 per cent of the new grandstand is expected to be operational when racing does return to Randwick in April.

The upgrade of Randwick's inside Kensington track has also necessitated some venue changes.

Of the five meetings due to be held there between March and June, two have been moved to the Randwick course proper with the other three to be split between Warwick Farm, Canterbury and Gosford.