Council officers discovered the dwellings at the rear of numbers 2, 4 and 6 Sunningdale Avenue, W3, in November 2013.
Landlord, Sofiane Belbegra, was served with a planning enforcement notice requiring the three units to be demolished.
His appeal against the notice was dismissed following a public inquiry in November last year, he was given until June 18 this year to comply.
The deadline passed with no action being taken, leaving the council with “no choice” but to send in bulldozers on August 22.
Councillor Julian Bell, leader of Ealing Council, said: “I am particularly pleased to see a really robust approach to enforcement being carried through and real consequences being felt by the unscrupulous landlord, as in this case.”
Mr Belbegra will be sent a bill for the cost of the entire works. If it is not settled a charge will be placed on the properties which will incur interest until the outstanding money is paid in full.
During the appeal in November, it came to light that Mr Belbegra was using the three main houses at Sunningdale Avenue as a hotel and flats, the council said.
It has since issued him with a further enforcement notice requiring these uses to stop, and an appeal against this notice is ongoing.