Thanks for the help David
Well thanks to all the stuff we read up here and on the Fuertaventura.com forum my sister has got her holiday sorted out
First off the TO tried to tell her that as they had only just found out about the building work that they didn't legally have to do a thing about it the my sis informed her that other people had had their letters over a week ago and read them the stuff from ABTA's site about them having to either refund (which she didn't want) or a replacement holiday of the same standard or higher for no extra charge. At that the girl started getting shirty and eventualy said that they would move her to another hotel for £500! Sis wasn't having any of that and stuck to her guns so the TO went to have a word with her boss and came back with a £200 take it or leave it offer

so my sister told them that a large number of people she had met on the internet were thinking of going to Watchdog and her solicitor had advised her to do something that I can't remember hehe. Next thing after speaking to her boss again the TO said that my sister can have the other hotel at no cost - Result!
Just goes to show that they are trying to con extra money out of people if they can....
Another thing is that the TO claimed that the only work going on is outside the hotel and the rooms and facilities are fine!
Thanks
-Angela-