Falmer could hold 30,000
The starting capacity for the American Express Community Stadium will be little over 22,000.
But, on the club's official tour of the stadium site, punters have been told that could be boosted by an extra 10,000 seats.
They would be built if the club becomes a success on the pitch and attracts new supporters and would not change the footprint of the site.
The extra seats would be fitted into the already planned lay-out - with 2,000 in each corner and another 2,000 plus at the top of the East Stand. The club says it held back from including the extra seats from the off as it could have caused additional problems in the planning process.
The club also announced this week that the North Stand would be free of sponsorship to reflect the popular terrace at The Goldstone.