Internal DPC

This may be a daft question but I really need to know this quickly.

We are having an extension built and the way it works out the finished floor level will be 2 inches above DPC level. I have no idea whether DPC inside matters and the only posts I can find seem to refer to outside.

We are having underfloor heating and tiles on it, the 2 inches includes tiles. It has to meet with the floor in an existing room and the builder misjudged the height as the door dividing new and old room was boarded over.

I have had a few problems with the builders and don't want to ask a stupid question so hoping someone here can put my mind at rest.

.....and the question is......?

once the polythene dpm is linked into the dpc, you can raise the level of the internal floor as much as you like.

Thanks for that, you answered the question even though I hadn't put it very well. It was also the answer I was hoping to see.