The legal status of the Rec has been the subject of dispute for many years
Bath Rugby has increased capacity at its Rec ground from 11,700 to 12,300 after the Charity Commission agreed to an extension to the IPL stand.
The ground is owned by Bath & North East Somerset Council as a charitable trust and the commission must oversee the ground's continued use.
Bath Rugby's chief executive Nick Blofeld said: "We hope to improve the facilities a little each year."
The rebuilding project is scheduled to start on 16 August.
Meanwhile, Somerset county cricket club have played their first game on a newly-laid wicket at the ground.
The county's second XI took on an Andy Caddick invitation team.
It is thought that The Rec, which was once the venue for Somerset's annual Bath Festival, could stage Twenty20 matches next season.