Following on from club-owner Vincent Tan's statement confirming the availability of £12m for development on the current 26,828-seater stadium, Borley confirmed any improvements would have to be done close season as construction would involve the removal of the ground's roof.
"We've never been presumptuous about our promotion. As a club it was a case of getting it done first and then worry about the other bits later," Borley told WalesOnline.
"Originally the stadium was designed for 30,000 to 32,000 but we've checked our calculations and reckon we could get it up to around 35,000."
Borley also went on to confirm that, despite reports, Cardiff would not play any of next season's Barclays Premier League matches at the 74,000-seater Millennium Stadium.