The four self-contained flats built across three adjoining properties on Ellerdine Road were knocked down around 10 months after the fine was issued in October last year.
Following pressure from Hounslow council's planning and housing enforcement officers, rogue landlords Palminder Singh and Nirmal Kaur Sanghera of Walton-on-Thames, Surrey were forced to take action before landing themselves in more hot water with the council.
Councillor Steve Curran, leader of Hounslow Council, said: “These rogue landlords acted just in time.
"Planning enforcement officers were poised to order the demolition of the buildings using a council contractor – and sending Singh and Sanghera a bill for doing so.
“For far too long, landlords like these have tried to let out sub-standard illegal housing to vulnerable tenants in the hope of making a quick profit.
"We are taking the strongest action possible against these unscrupulous individuals and will continue to do so until this blight on our borough is eliminated once and for all.”
Shocking conditions inside homes rented by pair
During a multi-agency raid in December 2014, officers uncovered 19 separate units across six properties owned by the pair who were fined £36,340 following a guilty plea.
The breaches included broken fire alarms, blocked fire escapes and poor kitchen conditions.
Four properties were issued with a notice for demolition and an appeal to the planning inspector saw the notices upheld forcing Singh and Sanghera to bulldoze the structures.
The council took another outbuilding out of residential use, along with two self-contained loft extensions and a management office at other sites owned by the landlords.