Seems so unfair when you have done all this for them .....you could do all the above (give them a date for moving) put for sale sign up.....erc ! You could also get an Estate Agent or two round (if you haven't already) to value the house ....make sure your S and his girlfriend are in when they come ...explain in front of agent your S will be gone and the room re decorated when you get some viewings ..oh, and casually mention they are looking for accommodation .....most agents nowadays also have rental accommodation on their books so he.she will have a good idea of deposit, montly rent, outgoings, etc .......and get your S to make an apt there and then !
I have two or three friends who have similar problems with their sons ...only one who has a problem with her daughter ! One friend, who had sold her house and bought a retirement apartment, was asked by her son to help him buy a house in London (and you know how expensive that is !) ...she gave him a lot of money ,,and told the younger son he would have the same when he found a house. Older then asked for more money to fit new ch and windows ....sensibly she said Ask your father (divorced years ago but he was a surgeon and had two houses !( ,,,2nd son then asked for his share, Refused because he would have squandered it, so money still in bank only for buying a property).....she sent him a small cheque on his birthday ..some months ago and hasn't heard from him since ! It is so difficult with grown up children nowadays ! Like a lot of you on here, neither I not my husband had any help whatever from our parents and would never have asked (not that they had anything to give anyway !) now it seems the norm sadly ! Best of luck ! ...ps you could tell him that if he stays there and the time comes when you need care the house will be taken by the Council in any case (whether it would or no !) 