It was the home of Michael and Elizabeth Le Marquand in Chemin du Moulin.
The house was gutted after a fire which had started in the garage spread to the main house.
Mr Le Marquand dialled 999 just after 4.30 pm after seeing smoke billowing from his garage.
Two fire engines arrived from St Helier 15 minutes later.
The Western Fire Station was unmanned at the time.
Western retained firefighters are only on call from 6 pm during the week.
Firemen tackled the garage fire, but it soon spread to the adjoining main house.
They had to keep their distance after being told that the garage might have contained a gas cylinder.