Apple Inc. said the construction of a new spaceship-like headquarters with a circular design in Cupertino, California, won’t be completed until mid-2016, later than originally projected, as the company revises its plans, Bloomberg reports.

The iPhone maker included the new timetable in an updated proposal it submitted to the city on Nov 14. While Apple, the world’s largest company by market value, had wanted to break ground on the 176-acre campus this year, the city may not complete its environmental impact report until June, and Apple may not be able to start work until 2014.

“They could conceivably break ground in 2013, but only if everything goes smoothly,” said David Brandt, Cupertino’s city manager. That depends on the city council approving the project quickly, and on residents not filing legal challenges. “The project is running a little bit slow.”

Apple notified the city in August that it planned to update its proposal in September. By filing in November, possible approval in early 2013 became unrealistic, said Brandt. In its original plan, the company said it envisioned moving in by 2015.

The new document includes no major changes from the ambitious plan that Steve Jobs presented to the city council in June 2011, four months before his death. Apple submitted revisions that will let it complete the project without having to truck out any dirt, and wants to move a free-standing, 1,000- seat auditorium farther away from one of the surrounding roads than in the original plan.

The company also wants to construct an additional building to house utility equipment and more parking spots for some of the workers Apple plans to employ at the new site, which the company pegs at as many as 14,200. Because many of the 10,500 parking spots will be underground, Apple said it intends to almost triple the amount of landscaped area. It has also removed from the plans a footbridge over a creek that runs through one corner of the property.

There are no substantial changes to the circular four-story main building, which at 2.8 million square feet will be one of the largest buildings in the world. The revised proposal includes the same artist renderings from the initial submission, which portray a glass-dominated structure surrounded by a landscape of native grasses and trees. The campus will include 7,000 trees.

The city plans to post the new plan online after Thanksgiving, by which time it will have added enough servers to handle the torrent of traffic it expects from Apple fans, said Aarti Shrivastava, Cupertino’s director of community development.