It’s a good day to be AT&T or Comcast in San Francisco. The Republican majority on the FCC today voted to protect their monopoly control of existing building wiring, claiming it would inspire competitors to wire buildings separately..

In a 3-2 Republican majority vote, the FCC today decided to pre-empt a San Francisco city ordinance that required multi-dwelling apartment, condo, and office space owners to allow competing service providers to share building-owned wiring if a customer sought to change providers.

“Required sharing of in-use wiring deters broadband deployment, undercuts the Commission’s rules regarding control of cable wiring in residential [multi-dwelling units], and threatens the Commission’s framework to protect the technical integrity of cable systems for the benefit of viewers,” according a news release issued by the FCC.

FCC Chairman Ajit Pai was joined by the two other Republicans on the Commission to block the San Francisco ordinance, which will allow dominant cable and phone companies like AT&T and Comcast to continue reserving exclusive use of building wiring, forcing would-be competitors to place costly redundant wiring in each building before offering service.

Pai said the city’s ordinance chilled competition because it encouraged competitors to re-use existing wiring instead of providing their own. That could harm the business plans of incumbent monopoly providers that depend on deterring or locking out would-be competitors by prohibiting them from using existing building wiring to reach customers. Pai called the ordinance an “outlier” and declared the city went beyond its legal authority by allowing a competitor to re-use building-owned wiring used by one provider to switch a customer to another. Pai added he had no objection to sharing unused wiring.

“By taking steps to ensure competitive access for broadband providers to [multi-dwelling homes and shared offices] while at the same time cracking down on local laws that go beyond the bounds of federal rules, our decision can help bring affordable and reliable broadband to more consumers,” echoed Republican FCC Commissioner Brendan Carr.

But critics contend the FCC’s decision to disallow required shared use of wiring will likely deter new competitors from entering existing buildings, because of the cost of installing redundant wiring. Others object to the FCC regulating the use of wiring owned and installed independently by building owners, not telecom companies. FCC Commissioner Jessica Rosenworcel, a Democrat who voted against the pre-emption, was unimpressed.

“We stop efforts in California designed to encourage competition in multi-tenant environments,” Rosenworcel told her fellow commissioners. “Specifically, we say to the city of San Francisco—where more than half of the population rents their housing, often in multi-tenant units—that they cannot encourage broadband competition. This is crazy.”

The FCC press release trumpeting the Republican majority vote to prohibit the shared use of existing building wiring was sympathetic to incumbent telecom giants AT&T and Comcast, which now dominate as service providers in multi-tenant buildings:

Nearly 30% of the U.S. population lives in condominiums and apartments, and millions more work in office buildings. The FCC must address the needs of those living and working in these buildings to close the digital divide for all Americans. However, broadband deployment in [multi-tenant buildings or ‘MTEs’] poses unique challenges. To provide service, broadband providers must have access to potential customers in the building. But when broadband providers know that they will have to share the communications facilities that they deploy with their competitors, they are less likely to invest in deployment in the first place. For decades, Congress and the FCC have encouraged facilities-based competition by broadly promoting access to customers and infrastructure—including MTEs and their tenants—while avoiding overly burdensome sharing mandates that reduce incentives to invest.