Ammonia concentration plays a significant role in broiler performance. High concentration of ammonia impairs the immune system and increases cases of respiratory disease in birds. Ammonia concentration can be reduced using various chemical additives such as zeolite. In the present study, spatial variability of ammonia concentration was investigated and analysed in two broiler houses. In House 1 (H1) sawdust only was used as litter material whilst sawdust used together with zeolite was used in House 2 (H2). Ammonia concentration measurements were taken from 21 points in each of the broiler houses. The readings were recorded at on a weekly basis using birds’ height as height measurement bases. In order to create spatial distribution maps, Inverse Distance Weighted (IDW) and Radial Basis Functions (RBF) methods were used and analysed. The performances of these techniques were assessed by using validation test methods (root mean square error (RMSE) and mean absolute error (MAE)) with the best performing method (lowest RMSE and MAE) being selected for creating ammonia spatial distribution maps. The results indicated that spatial ammonia distribution is more uniform in H2 compared to H1. It was also observed that ammonia levels were lower in H2 than H1. The presence of zeolite as a litter addition can be attributed to study findings positively affected the broiler performance. It was considered that using zeolite with sawdust as litter material significantly reduced ammonia concentration. In H1, higher ammonia concentrations of greater than 25 ppm were recorded near ventilation fans and at the centre of the house. Because of this it is recommended to install additional fans at middle of the house for remove harmful ammonia.