Titirangi Scaffolding Limited pleaded guilty in the Waitakere District Court last week to one charge of failing to install or arrange the scaffolding so that it was safe to use.
The company had been contracted to erect the scaffolding on a residential renovation site.
But it had not properly secured scaffold planks on a sloping access platform to prevent against creep, movement, horizontal displacement or uplift.
Last September, the homeowner fell about five metres onto the ground below after the plank she stood on gave way.
She was in hospital for two days after suffering a broken shoulder and bruising to her face, neck back and abdomen.
Titirangi Scaffolding was convicted, fined $20,000 and ordered to pay the victim $7000 in reparation.
The Ministry of Business, Innovation and Employment said the failure to secure the planks in accordance with scaffolding guidelines and New Zealand standards was not picked up in four inspections by a director of the company
"That's a woeful lack of attention to a major hazard which has caused a serious injury,'' said Keith Stewart, chief inspector investigations for MBIE's health and safety group.
"The homeowner had a right to expect that this equipment would be fit for use, but the company's failures have resulted in her suffering needless serious injury.''