The general contractor responsible for the Marriott Marquis Convention Center hotel has filed suit against the project’s architect, alleging design flaws in key parts of the hotel.

Colorado-based Hensel Phelps Construction filed the lawsuit last week against Atlanta-based Cooper Carry in U.S. District Court for DC. Hensel alleges that Cooper failed “to timely perform its obligations in a manner to support timely completion of construction," and failed "to meet the standard of care of an architect as prescribed by the Design Contract," the Washington Business Journal reports. Among the design issues listed in the suit are top-of-wall details in guestrooms, the smoke control system and a failure to properly coordinate door hardware. The two sides engaged in pre-suit mediation but were unable to settle the matter.

The $520M, 1,175-room hotel and conference center was partially subsidized by the District government and opened in May 2014. The 1.1M SF Marriott Marquis spans 15 stories and includes 83 meeting rooms, the city’s largest ballroom, multiple restaurants and a 24-hour business center. Just last month, a report from the DC auditor showed that early returns on the hotel looked promising, with 401k rooms booked for this year. Looking ahead to next year, 422k rooms have been booked in advance while over 528k rooms have been booked in advance for 2017. [WBJ]