Four in 10 homes will be vulnerable to issues such as frozen pipes and boiler breakdowns if the predicted freezing weather hits the UK this week.
The Met Office is predicting snow, sleet and heavy rain in many areas, yet householders have not taken measures to protect their property, according to Direct Line.
Those aged 18 to 34 are the least likely to have made preparations for winter, the insurer’s poll suggests.
It also appears that Londoners take the most cavalier attitude to protecting their homes, with only 50 per cent of properties already primed for the advance of a big chill, the study shows.
At the other end of the scale, 71 per cent of people in Northern Ireland and two-thirds of those in the North West have already taken measures to protect their property in some way.
Stuart Curson, head of the home insurance group, said: “As the last two winters have demonstrated, bad weather can cause serious damage to property.
“While this winter has proved mild so far, the current weather predictions should ring alarm bells for many householders.”