The SF Planning Commission on Thursday approved a plan to convert the top two floors of Nordstrom at the Westfield mall into 50,000 square feet of new office space.

Office space is in high demand these days in downtown San Francisco, while retail space is not, and the owners of the shopping center say that they see the conversion as a win-win, since office workers become de-facto customers for the retail space below. The Westfield development already has some attached office space on the opposite side of the complex in the former Emporium building at 845 Market.

Floors 7 and 8 at Nordstrom will soon disappear under the plan, as the Chronicle reports, while the store will continue to exist on floors 4, 5, and 6 of that half of the mall. And the shrinking footprint of Nordstrom comes as Barney's is about to disappear over on Stockton Street, and Macy's recently closed and sold its men's store to make way for office and other uses.

Currently, under a 1986 ballot measure known as Prop M, San Francisco developers are held to a citywide cap on new "large" office development — those that are 50,000 square feet or larger — of 845,000 square feet. Mayor London Breed has placed a measure on the March ballot that will add millions of square feet of potential new office space to a pool based on all the former office space that has been converted to other uses since 1984. The measure would prioritize approvals for new office developments that offer subsidized rent for retail and community spaces as well, and increase the size definition of "large" office projects from 50,000 to 100,000 square feet, making mid-size projects easier to approve.

Karin Flood, executive director of the Union Square Business Improvement District, tells the Chronicle that she supports the Westfield's move to shrink Nordstrom. "There is less demand for retail space in Union Square [right now], and it is particularly hard to find retail tenants who are interested in filling the upper floors of a building — even in a shopping center,” she says.

It's unclear what Nordstrom departments will be shrinking as a result of the change, but the store is about to get two-fifths smaller than it currently is.

Union Square is seeing troubled times as retailers are struggling all over the city and the country amid a shift to online shopping. As the Chronicle reported in October, with this year's closures of Gump's, Forever 21, and the Macy's men's store, the district feels like it's rapidly contracting. And the shrinkage over at Nordstrom is yet another symptom.

Photo: Josta Photo/Flickr