Massive sliding glass doors now being installed at Apple's new flagship Union Square San Francisco store

Apple's new flagship store at Union Square in San Francisco is now nearly structurally complete as massive, movable glass doors are being installed to its front, three blocks away from the company's existing flagship store at Stockton and Market Street (which the new location is slated replace this summer).

Work on the new Apple Store, which was just getting started last June (below top) and topped out in September (below middle), has now built out the new location's two level box with glass on both sides. Also evident is a strip of glass that runs up the building's side (below bottom).

Site last June

Site in September

Site today

Wide angle shot

While similar in form to the design of the West Lake store built in China (featured in a grand opening video during the company's "Spring Forward" event last March), the new San Francisco store is unique in that it will incorporate giant sliding doors on the front of the building (below), enabling the location to take full advantage of the city's pleasant climate during business hours.

Last year, the work to remove the former triangular building (below) was just getting started. At the time, a source familiar with Apple's construction timeline said the new Union Store location wasn't expected to open until the summer of 2016. The current progress indicates that the project appears to be sticking to that schedule.

Central Subway construction slightly eases in front of existing SF flagship location

Apple's existing flagship store in San Francisco opened just over twelve years ago in February 2004. It was one of the company's first "high profile" retail locations, featuring a prominent glass stairway positioned under a large skylight. As with its new location today, Apple built its existing store from the ground up after demolishing the previous building on the site.

Apple's current store, located three blocks away from the new construction site, is at the intersection of Stockton, Ellis and Market Streets. The location has been plagued with nonstop construction of the Central Subway for years, which has dug underneath Stockton using tunnel boring machines.

While intended to be minimally invasive compared to digging a "cut and cover" subway passage, the tunnel boring work has closed Stockton Street for more than three years. The street (which passes in front of the current Apple Store) isn't expected to reopen until 2017 at the earliest, although the side street (Ellis) has now been partially reconstructed over the escavated pedestrian tunnels that pass below it.

Existing store from Market Street

To the left of the store, the street remains torn up for subway construction

The construction work over the last two and a half years hasn't stopped customers from lining up around the block for the iPhone 5, iPhone 5s, iPhone 6 and 6s product launches, and Apple's store remains very busy virtually of the time, particularly during the holidays.

Once the Central Subway is finished (perhaps as early as the end of 2019), new underground pedestrian walkways will connect the existing Powell Station to the new north-south subway line stopping at a new Union Square station a couple blocks away, on the opposite corner of the park from Apple's new store.

Apple's other major construction projects nearby

Outside of the new San Francisco flagship store, Apple's major construction projects nearby in California include Campus 2 and its Phase 2 component, as well as an $850M solar farm being built by an energy partner in Monterey County to the south and rapid, massive expansions of its iCloud data center facilities in Reno, Nevada to the east.