From the site:
Stadium Expansions
Each team will start with a stadium with a capacity of 30,000. During the Mid-Season and End of Season periods teams may choose to expand their stadium. Expansions will be done in lots of 3,000 with a maximum of 18,000 seats at one time. Teams with larger stadiums will be charged more in Ground Maintenance which will also be deducted in half-season fees. Everybody's stadium will start off at 30,000. To purchase 3,000 seats you will have to pay $500,000 then for every expansion range after that you can take off $15,000 of the $500,000 for the 3,000 seats. So for example if someone was to purchase an 18,000 seat expansion they would have to pay $2,735,000 ($500,000 + $485,000 + $460,000 + $445,000 + $430,000 + $415,000). EVERY TIME A TEAM MAKES A STADIUM EXPANSION IT WILL TAKE AWAY THE HIGHEST POSSIBLE EPANSION YOU CAN MAKE (e.g if you expand your stadium by 3,000 seats you will lose your expansion of 18,000 available). If you expand your stadium in sequence (18,000 then 15,000 then 12,000 then 9,000 then 6,000 and finally 3,000) you will be able to achieve a capacity of 93,000. Due to the reputation of the European Football League builders will work at an amazing rate to ensure the club's stadium WILL be built before the season resumes. TEAMS MAY ONLY EXPAND THEIR STADIUM ONCE A SEASON.
