Patrick Cassidy, 24, of Stanborough Avenue, Borehamwood, was sentenced after being convicted of one count of aggravated burglary, one count of escape from lawful custody, and one count of domestic burglary.
He had pleaded guilty to the count of escape from lawful custody and was found guilty by unanimous jury for the other counts.
At around 9pm on November 17 Cassidy entered a property on Bradley Road, Slough. A man in his eighties and a woman in her seventies who were both asleep were threatened with a knife and told to hand over money and gold. A search was carried out and Cassidy left the house empty handed.
Police caught him a short distance away and he was charged on November 18.
The other charge of domestic burglary relates to an incident just hours before in which Cassidy forced entry into a property in Eastbury Road, Watford and took a handbag.
Cassidy was serving a sentence at HMP Hollesey, which is an open prison. On August 13 he was found to be missing at the morning roll call and did not return. He was subsequently charged with escaping from lawful custody.
Cassidy was sentenced to 15 years prison with three years to be spent on license at Reading Crown Court on Friday, August 21.
Investigating officer, Detective Constable Ben Walker-Hall of the priority Crime Team based at Slough police station, said: “Cassidy entered the homes of two older people who were asleep at the time and then threatened them with a knife.
“This was an extremely harrowing ordeal for the two victims, with someone coming into their family home.
“I am satisfied with the sentence handed out to Cassidy which will give him time to think about his frankly cowardly and atrocious criminal behaviour.”