The man in custody suffered minor injuries in the crash on Highway 7, east of Islington Avenue. It took place Wednesday at approximately 10:45 p.m.
Police say one of the cars left the road during the crash and hit the outside of the townhouse, breaking a window and damaging the frame.
The car was a mangled wreck on the lawn of the complex when police arrived.
Highway 7, which was blocked from Islington Avenue to Wigwoss Drive, has been reopened following a police investigation.