A landlord has been landed with a bill of over £300,000 after he added illegal extensions to seven of his properties and ignored enforcement notices in his quest for greater rental income.

He will now have to hand back that extra money – nearly £218,000 in illegal rental income.

William Lao, who owns a total of 16 properties in Waltham Forest, London, had failed to apply for planning permission when he added loft and side extensions to his properties, converting them into flats and in some cases virtually doubling them in size.

In doing so, he breached HMO regulations, including fire safety requirements, and was unlicensed.

While Waltham Forest Council made “strenuous” attempts to address the issues over a five-year period, Lao refused to return the properties to their original size.

He has now been fined £73,500, made up of £10,000 for each of the seven enforcement notices that were ignored; £3,000 in relation to various breaches of HMO regulations; and £500 relating to an improvement notice and a failure to disclose ownership.

He was also ordered to hand over £217,758 in illegal earnings from renting out properties that were in breach of planning controls and must pay £10,000 towards Waltham Forest Council’s costs.

He has six months to pay or faces six months in jail.

Lao will also now have to demolish the illegal building work and return the properties back to their original condition.

Cllr Clyde Loakes, deputy leader and cabinet member for environment, said: “We’re really pleased to have finally brought this rogue landlord to account and seen him rightly punished for a catalogue of breaches.”

In court, Lao’s advocate asked for leniency in the sentence, saying his client realised his tactic for making money was a “huge mistake”.