A woman was killed and her lodger left unable to eat or breathe without machines after they were poisoned by carbon monoxide, a court has heard.
Elouise Littlewood, 26, was found dead at her flat in Bedfont, west London, on 27 February 2008.
Her lodger, Simon Kilby, then 32, remains unconscious.
Gas fitter Paul Williamson, 53, of Chaucer Gardens, Sutton, south London, is accused of manslaughter by gross negligence and grievous bodily harm.
‘Unable to communicate’
Prosecutor Edward Brown QC told the jury: “Mr Kilby remains to this day in what is described as a low awareness state.
“Today he is unconscious and remains unable to speak, to move, to communicate and unable to eat or breathe without machines to help him.”
When police broke into the flat in Wooldridge Close they found Miss Littlewood dead in the bathroom and Mr Kilby unconscious in the living room.
The heating in the newly-built flat had been on constantly the night before.
Both had seen their health deteriorate in the weeks beforehand, with Mr Kilby taking time off from his job as a tree surgeon, the Old Bailey heard.
Miss Littlewood, who trained people to work in childcare, would sometimes vomit at work.
Mr Williamson is accused of failing to examine the effectiveness of a flue after carrying out work.
His employer, Malden Plumbing and Heating Limited, is accused of a breach of health and safety rules.
The case continues.