Prevent rdlc subreport from growing and moving within main report

I keep dealing with visual studio 2013 report designer.

My biggest problem at the moment is to spare exaclty one sheet of a4 paper (210 mm * 297 mm) per every data record. The length of the details section of the main report varies all the time depending on the lengths of subreports and (seems to me) something else.

Is there a way to keep unchanged both the size and location of a subreport within the main report ?

Thank you in advance !

via Chebli Mohamed