A main criteria for a proper door installation nowadays is the support of the door to prevent sagging and thermal bridging underneath the threshold.
It´s frustrating to see how many doors will be fitted in Ireland every day on pieces of blocks or timber, to adjust the right finishing door height. The same principle was used in Germany almost 30 years ago and was wrong at this time already!
There are different solutions available now, to install a door in an appropriate way, by using special adjustable brackets or pre-fab high density bars. A suitable solution is just a phone call away - 066 4014045.