You actually make a valid comment regarding the threshold which is now bob on flush with internal floor. In hindsight, during his visit when he measured up, he did enquire as to whether there were any young children or elderly persons at the property, of which there is both......
This guy...
Yes doors are UPVC....I couldn't understand why he would have the sill below DPC.....I suspect he incorrectly measured up......
Having said that he did do what appears to be a first rate installation.....
As a newcomer to DIYNot I thank you for your reply Gazman...much appreciated!!!!!