Paramount may be planning an ambitious, $700 million overhaul to its lot over the next couple of decades, but don’t expect a visible facelift to the historic buildings on the 56-acre Melrose Avenue lot.

Most of the upgrades will take place inside existing structures, with several facilities swapping locations to eliminate the need for lengthy travel across the lot and others getting major upgrades to lure more production biz and improve energy efficiency.

All the changes will be made with the goal of preserving the historic integrity of the studio, Paramount chairman-CEO Brad Grey told Variety. “Our plan is to invest in the quality of our lot, its technology and infrastructure, to help our studio remain vibrant and grow jobs over the long term, while at the same time respecting its great Hollywood legacy,” Grey said.

It’ll be at least two years before the hard hats come out, as the master plan that the studio unveiled Tuesday must be submitted to the city of Los Angeles, with an environmental review and public hearings to follow. Called the Hollywood Project, the plan, which insiders say was championed by Grey, is expected to create thousands of jobs.

Some of the more significant upgrades and renovations, designed by Rios Clementi Hale Studios and Levin & Associates Architects, would include:

• State-of-the-art soundstages with new climate control and lighting systems. Currently, entire buildings are centrally air-conditioned, creating massive energy waste. Studio will install modular climate zones that focus mainly on brightly-lit areas where heat is generated.

• An all-new, high tech, 400,000-square-foot post-production village in the center of the lot. It will include editing bays, sound editing facilities, and other post equipment that will enhance the studio’s post capabilities. Studio currently shares its post facility with Technicolor, which it opened in April in a much smaller building than the one it has planned. The standing facility has half-a-dozen new recording studios with the latest technologies in sound, as well as dozens of new state-of-the-art editorial bays.

• The studio is also looking to improve circulation for its trucks and trailers, solving a problem it inherited when it purchased rival RKO Studios’ Gower Lot in the 1960s. While that expanded the studio’s square footage considerably, the separate roadway systems didn’t mesh up well, creating a headache for drivers that Par plans to rectify.

When the project finally gets under way, Paramount will tackle the entire project all at once to over the next 25 years, an approach that will allow for most of the existing buildings to appear unchanged.