Major renovation - new construction

I think it is in the glossary in the Reference Guide. Usually a major renovation involves the replacement of major building systems like windows, HVAC, and lighting. It should be more than cosmetic and likely involve any people living or working in the space to have to vacate that space. The greater the extent of the renovation the easier it will be to address sufficient LEED credits to earn certification. Obviously there are degrees of renovation and there is not a firm line that gets crossed to be a major renovation. For LEED I would say it is major enough of a renovation if the scope of work allow you to earn sufficient LEED points related to your project goals.