The number of people living alone in Scotland is predicted to increase by almost 50% in 25 years, figures published today showed.

In 2006 there were 809,000 homes with just one person living in them - some 35% of all households.

But that is projected to rise to more than 1.2 million - or 44% of the number of households.

Duncan Macniven, the Registrar General for Scotland, published details of the number of households which showed that in mid 2007 there were 2.3 million households in Scotland - more than 270,000 more than the total from 1991.

And while the country's population has increased by about 1% since 1991, the number of households has gone up by more than 13% since then.

This is because households are getting smaller, with more people living alone or in smaller groups.

Mr Macniven said: "Over the past 15 years, Scotland's population has increased by 34,000.

"However the number of households has increased at a far greater rate - by over 250,000 - because the average household size is getting smaller, as more people live alone and in smaller households."

He added: "This trend is predicted to continue. Over the next 25 years, the number of households is projected to increase by almost a fifth to 2.7 million - an average of 17,600 additional households per year."

Mr Macniven explained: "Scotland's population is ageing, with more people in the older age groups and fewer in the younger age groups.

"This has an impact on household structure, as children tend to live in larger households, and older people in smaller ones. Since 2001, the number of households containing just one adult has increased by 8%, and the number of two adult households increased by 7%.

"By 2031, one adult households are projected to increase by almost one half and two adult households will increase by a quarter."

He also said that the average household size had fallen from 2.45 people in 1991 to 2.19 in 2006 and was projected to decrease further to 1.93 in 2031.

As the population ages, the number of households headed up by someone aged 60 or above is projected to increase from 753,000 in 2006 to 1.14 million by 2031 and the number of households headed by someone aged 85 or over is also projected to rise from 69,000 to 177,00 over the same period.

The figures also show that the number of households in different local authority areas is projected to change at varying rates.

Orkney, West Lothian and Edinburgh are all projected to have increases of 35%, while in Inverclyde and East Dunbartonshire the number of households in projected to drop by 3% and 2% respectively.