Absolutely mammoth penthouses may crown San Francisco's in-progress towers at 201 Folsom Street. Yes, this is LUMINA: Luxury New San Francisco Condominiums. And it's also some Bruce Wayne, Lex Luthor, Tony Stark shit.

Socketsite reports that commercial Real Estate Firm Tishman Speyer is mulling the combination of up to eight three-bedroom units across the 41st and 42nd floors of one tower, which could measure over 20,000 square feet. Meanwhile, four three-bedroom units on the 37th floor of the other tower could be joined for 9,000 square-feet of penthouse enormity. Private roof decks are a possibility, and Jesus, why not.

If the first uber-duplex (a combined 24 bedrooms) comes to pass, then lo, it will be the actual largest residence in San Francisco. Currently that honor belongs to the 18,000-square-foot penthouse in the St. Regis at 188 Minna. That, itself a three-unit merger, sold for a record-setting $28 million back in 2011.

And, for the doubtful, it seems highly possible that the unit mergers would conform to the already approved plans and also be met with approval. It all depends on market demand, so let's just hope no one wants this sky-monster. But hey, if you're intrigued, Mr. Wayne...

SALES GALLERY: 289 Main Street, San Francisco, CA 94105
Phone: (415) 495-3600

[Update] Well, it's happened. Here's one penthouse proposed listing at a cool $49 million, though it won't be 20,000 square feet as predicted.

Previously: SF Is Top 5 City For Extra Home Purchases By The Uber-Rich