Yunus Oomerjee, 56, of Framewood Road, Slough, illegally extended and converted a bungalow in Eastcote Lane, South Harrow, into "seven shoddily-built dwellings and a studio".
According to Harrow Council , the flats were poorly constructed without building regulation, fire safety or electrical checks and Oomerjee feigned ignorance of council notices.
He was ordered to pay £355,000 at Willesden Magistrates' Court in confiscation proceedings on May 4 and was also fined £1,250 and £15,000 for costs.
The confiscation order was made to recover the money the rogue landlord made as a result of failing to comply with five enforcement notices from Harrow Council .
Oomerjee was found guilty at Harrow Crown Court on June 20 and was sentenced on May 4.
Speaking after the sentencing, Councillor Graham Henson, leader of Harrow Council, said this is a victory for both the council and for Oomerjee's "long-suffering neighbours".
"Planning is not a pushover – and we've now given this bungalow bungler a very, very expensive lesson," Cllr Henson said.
"This is not just a victory for Harrow Council, it is a victory for Mr Oomerjee's long-suffering neighbours along Eastcote Lane and for all decent landlords in Harrow who obey the law."