Island of Koh Phangan off the coast of Koh Samui, Thailand. Paula Bronstein - Getty Images

British retirees Les and Sally Page had never considered retiring early in Asia, until a holiday to Thailand five years ago prompted a snap decision. "We were on holiday on the island of Koh Samui and within five days we both knew we wanted to retire there," said 59-year old Sally. "It has a magical feeling that can't be explained." The appeal of retirement in Thailand extends beyond the idyllic beaches of the island. The British couple said the Southeast Asian country boasts better weather, a greater variety of activities, a slower, easier pace of life and cheaper cost of living than what they are used to. The Pages are just one couple in a burgeoning group of western retirees who have decided to spend their golden years in Asia.

Immigration figures show that British, American and German retirees made over 35,000 applications for retirement visas in Thailand in 2011 and is forecast to grow to 45,000 by the end of 2013, according to Sasha Nugent, analyst at U.K. based foreign exchange Caxton FX. Nugent is seeing more and more U.K.-based retirees moving to Asia. "The most popular countries appear to be in South East Asia, in particular Thailand and Singapore," she said. (Read more: Retirement villages – No longer a taboo in Asia) Mea Attwood, a 58-year old British retiree who moved to Thailand five years ago, said cheaper living costs in comparison to the U.K. have allowed her to live a more luxurious and healthier lifestyle than she would at home. "We are able to look after ourselves better in Asia. We can afford regular massages, for example, something that would be a real treat in the U.K.," said Mea. "Plus there is no council tax in Thailand, and water and electricity is cheaper," she added. Interestingly, Caxton FX's Nugent said Singapore still manages to lure a large number of expat retirees, despite the fact that living costs, particularly the cost of renting or buying property, are relatively high in comparison with the rest of Asia or the United Kingdom. "Although generally, [Singapore] is just as pricey as the U.K. in terms of living expenses, there is good and low cost travel, not forgetting the cultural benefits," she said, adding that the city state is also viewed positively because of its financial stability and good banking system.

(Read more: The aging in Asia face a new decade like no other)