Maybe this has been dealt with before, but it's all new to me.

I quote from a recent article, written by a Thai lawyer:

.....Under Thai laws, ownership of a house can be separated from land. There is precedence of the Supreme CourtNo. 301/2538 (1995) affirming this concept. The house can be registered under the name of a foreigner who may request for the special House Registrtaion Certificate (Tabian Baan) Thor.Ror.13.

It can be the case whereby a foreigner buys the empty plot of land in his Thai wife's name and the latter registers the 30 year lease of habitation for her foreign husband. In this connection, the husband can apply for a construction permit under his own name.

With these documents, the husband will have ownership of the house or building and moveable properties inside the house, and also be able to apply for the "Yellow Book".......

Can anyone confirm if the above is correct, and if so, whether this is a viable alternative to the more traditional routes of farang house 'ownership'?

Yes, as I understand it this is legal. However, one must consider the practical value of a lease in the event of, say, divorce or separation. If the answer to that is 'not much', then the house may be lost.

Have a look at the recent poll on types of land ownership and you will see that over two thirds of voters said that their wives own both the land and the house.