Budkowski has recently been restructuring Renault in the background, but says that those efforts will need to continue even after Daniel Ricciardo joins the team.
"We're currently 1.5 seconds from the best," Budkowski admitted to France's Auto Hebdo.
"It would be ridiculous to say that we can erase this deficit when you consider organisations like Mercedes and Ferrari.
"But Renault is now a big organisation that continues to grow. At the end of the season, we will have grown by 50% compared to the workforce present at the buyout of Lotus in December 2015.
"We will be close to 700 people at the end of year but that does not mean that the fruit of the collective work of these 700 people will be visible from January. When people arrive, a time of adaptation is necessary. When you have young people, you have to train them.
"And we recruited a lot of apprentices and newly-graduated talents. We are only now seeing the benefits of the recruitments of 2016 and 2017 now."
Renault are currently fourth in the constructors' championship.