Just be careful what you're getting quoted for.

Will this include delivery to site, placement at the location, fitting the doors and making good?
It's important to know.
Plus as I said, you'll need to have a properly designed support beam to fix the door rail to and a proper threshold detail to avoid water penetration.
ONQ
http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,22447,en.pdf (<br />)[broken link removed]
All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.