Kathleen Napier first began complaining to Islington council about the temporary accommodation on the Hornsey Lane Estate in February 2018.
The three-bedroom flat had a cockroach infestation in the kitchen and damp and mould throughout, solicitors said.
The fire alarm was broken, there was no ventilation system, doors were falling off and there was a large hole in the floor of one of the bedrooms.
Exterior walls also had cracks or bricks missing and drain pipes were leaking.
Ms Napier contacted lawyers after repeatedly complaining to Islington council
“It’s absolutely unacceptable that a tenant would have to live in these uninhabitable conditions,” said Larissa Ellis from High Street Solicitor’s housing which represented Ms Napier.
“The third bedroom is a health hazard as the floor is incredibly dangerous and a broken fire alarm poses a serious risk to the family.
“The cockroach infestation, mould, damp and lack of ventilation further add to the unsatisfactory state of the property.
“Kathleen had been complaining to the landlord to have the property brought up to a habitable standard, without avail, and was left with no other option but to seek legal advice.”
Ms Napier was awarded £2,500 in compensation and the family have now been moved to a new home.
“We are very happy that we could help her ensuring that she is permanently transferred to a different property, she is compensated, and the disrepair is resolved for the next tenant,” added Ms Ellis.
Islington council said it paid compensation in relation to a “structural issue” in the flat.
A spokesman added: “We are committed to ensuring that each and every person that lives in our borough has a decent, safe and secure place to call home.
“When a tenant comes forward to the council with an issue in their home, we work with them to resolve this quickly and effectively.
“The council places its tenants at the heart of its work, and we have worked with Ms Napier and the other occupants of the property to provide them with a suitable offer of re-housing, which they have accepted.”