The 38-year-old, of Beckenham, who does not want to be named, damaged his spinal cord in the incident at Grove Park in south London.

He is no longer able to walk or work and  and will need to use a wheelchair for the rest of his life.

Southwark-based Habitat Construction was sentenced after pleading guilty to safety failings following an investigation by the Health and Safety Executive.

Southwark Crown Court heard the injured worker was part of a team converting two former Victorian hostels into four-single town houses.

During the work windows were removed from the buildings, which HSE established happened in an ad-hoc and uncontrolled manner with no safety guarding or boarding.

The missing windows included several on a raised first floor area, which created openings at just above floor level.

The worker fell through one of the missing windows while attempting to connect a temporary electricity supply, losing his balance and plunging 8m onto the concrete floor of a basement below.

Habitat Construction LLP, of Southwark Street, London, SE1, was fined £110,000 and ordered to pay £16,620 in costs.

After the hearing, HSE inspector Toby Webb said: “We found a catalogue of working-at-height risks throughout the site, including the use of simple netting as edge protection to a deep excavation and the removal of windows without installing appropriate protection.

“The unguarded windows posed a clear and extremely serious risk, not only for this unfortunate worker but for others at the site who worked near what were effectively open voids.

“Sub-contractors were also placed in danger because there was nothing to stop equipment or debris from falling from the window spaces.”