The responsive pleading of the defendant shall state as a counterclaim any claim which he has to compensation for buildings and improvements on the premises and may request an estimation by the jury of the increased value of the premises by reason thereof. The plaintiff may file a request, in writing, that the jury would estimate what would have been the value of the premises at the time of trial, if no buildings had been erected, improvements made or waste committed. Both these estimates they shall make and state in their verdict. The jury shall allow for no buildings or improvements, except those that they find were made by the defendant, his grantor or assignor, and were judicious and proper under the circumstances.