have you gotten all the correct certs for all works done to this stage? provisional BER, structural, building regulation and planning?
what part of the country are you in? some potential purchasers of half built homes are checking for pyrite etc..
second fix is a dangerous term when used by an estate agent, there may not even be insulation installed.
my advice would be to thread very carefully, these half finished houses are proving a difficult proposition to survey, calculate and complete becasue its hard to know whats done/completed (or more to the point what not done & covered up.. )
IMHO it is very likely, you'll be buying the tail-end of the worst construction standard fiasco in Irish history. do consider independent professional advice from a building surveyor or architect is going to be much better than from a builder