San Francisco’s Department of Building Inspection is investigating Elon Musk’s newly renamed Twitter for installing a large X sign on the roof of its Market Street headquarters without a permit.
Patrick Hannan, a department spokesman, said planning commission approval and a building permit are required to ensure the sign is structurally sound and installed safely.
The X, made of a thin black metal that looks like scaffolding, looked small on the historic building’s roof. A piece of fabric filling the thicker side of the X fluttered in the wind Friday afternoon.
The sign was not visible at all from the south side of Market Street, where the building stands. Passersby on the north side of the street, from where the new sign was visible, hardly noticed, some only looking up when they noticed a news camera trained on the sign.
Far more visible were the remains of the original Twitter sign on the side of the building. On one side, the letters were removed, leaving behind a gray outline made of the metal used to hold them up. On the side facing Market Street only the r had been removed and the third side was still intact.
X leases office space in the building from Shorenstein and JPMorgan Chase, which owns the property.
Workers stopped removing the sign last week when building management called police and said they were not informed of the sign change. While a permit from the city is not required to remove the letters, Hannan said, changing the letters would be necessary.
Twitter’s lease also requires permission from the landlord to change the sign, and it’s unclear whether the company has received it.
Reach Danielle Echeverria: danielle.echeverria@sfchronicle.com; Twitter: @DanielleEchev