The 23-year-old, from Gateshead, who does not want to be named, was injured on a site in Earsdon View, Shiremoor, when the incident happened on 4 December 2012.
The agency worker broke her right wrist, fractured her forehead, jaw and cheekbone, and sustained a hairline fracture to her right hip.
She also severed tendons in her left hand and suffered extensive bruising to her face, neck and back.
She had to have a metal plate inserted into her right arm and required further surgery to ease later complications.
She was unable to return to work as a labourer for six months and still suffers constant pain. It is unlikely she will ever return to her usual trade working as a plasterer.
North Tyneside Magistrates’ Court heard how the worker had been clearing rubbish on the first floor of a property nearing completion and was on the landing talking to another worker in the ground floor hallway.
As she leant on a temporary handrail on the landing it gave way, causing her to fall around 2.6 metres to the floor below.
The HSE investigation found that the temporary handrail was a single piece of timber fixed to the protective cover of an upright post at one side and nailed with one nail into a timber door frame at the other side, which was where it gave way. There was no mid-rail to provide additional support.
Bellway Homes Limited, of Seaton Burn, Newcastle, was fined £10,000 after pleading guilty to breaching safety regulations.
Speaking after the case, HSE Inspector Emma Scott said: “This incident could easily have been prevented if Bellway Homes Limited had ensured that temporary guard rails were erected and installed correctly.
“Instead a young worker has been left with serious injuries which are still causing her pain and may well prevent her from continuing work in her chosen trade.
“The significant dangers of death and serious injury associated with falls from height during construction work are well known and long standing in the industry, and working on a landing area without suitable safety measures in place is simply not acceptable.”