The Scot is looking to further improve the club both on and off the pitch during the close season.
"You have to keep building," said Lambert. "Next year will be really tough again. Finances dictate a lot of stuff.
"If you go and buy experienced players and names, they command a lot of money. I have to keep building this squad. It will have to be rebuilt. It's still in a transitional period.
"To develop it the way you want - not just the team but the club - you have to implement your own ideas and what you want to do. That's not just on the pitch but off it too."