The £12 million job involves work on a new North Stand, which will help increase capacity from 17,500 to 30,000 making it the largest dedicated club rugby union stadium in the UK.
The Tigers had scheduled for work to begin before the end of the summer. Function spaces, a club shop, ticket office and club bar will also be built in the stand.
Remaining phases will include a standing lower terrace, an all-seater upper terrace and executive boxes.
Other plans for the scheme include a three-star hotel, a 450-space multi-storey car park and an educational building for people with multiple learning disabilities on behalf of the adjacent Leicester College.
The whole project has a programme timeframe of about 10 years.