Foreign investment into Thai property has started to be viewed more favorably by Thai banks. Instead of credit risk they are an opportunity for economic growth. Thailand mortgages are generous with on average 50% being offered to first time buyers, as much as 70% for established developers with a proven track record.
This said, most private investors are still opting to take out Thailand mortgages from a lender at home and then transfer the funds to their Thai bank account. More and more developers also offering mortgages that can be taken out at different stages of phases of the construction depending on the type of purchase.
As with buying a property, there is also the option to take equity release from your home property. This option holds its obvious benefits but should be discussed with and is largely down to the original mortgage lender. Speaking with your lawyer and a reputable financial advisor will help insure you make the right decisions for your foreign purchase.