diff --git a/src/org/cpsolver/exam/model/ExamModel.java b/src/org/cpsolver/exam/model/ExamModel.java
index 95dbcac1..13ce94db 100644
--- a/src/org/cpsolver/exam/model/ExamModel.java
+++ b/src/org/cpsolver/exam/model/ExamModel.java
@@ -571,6 +571,8 @@ public Document save(Assignment<Exam, ExamPlacement> assignment) {
                 r.addAttribute("name", room.getName());
             r.addAttribute("size", String.valueOf(room.getSize()));
             r.addAttribute("alt", String.valueOf(room.getAltSize()));
+            if (!room.isHard())
+                r.addAttribute("hard", "false");
             if (room.getCoordX() != null && room.getCoordY() != null)
                 r.addAttribute("coordinates", room.getCoordX() + "," + room.getCoordY());
             for (ExamPeriod period : getPeriods()) {
@@ -868,6 +870,7 @@ else if (root.attribute("initiative") != null)
                     Integer.parseInt(e.attributeValue("size")), Integer.parseInt(e.attributeValue("alt")),
                     (coords == null ? null : Double.valueOf(coords.substring(0, coords.indexOf(',')))),
                     (coords == null ? null : Double.valueOf(coords.substring(coords.indexOf(',') + 1))));
+            room.setHard("true".equalsIgnoreCase(e.attributeValue("hard", "true")));
             addConstraint(room);
             getRooms().add(room);
             rooms.put(new Long(room.getId()), room);
diff --git a/src/org/cpsolver/exam/model/ExamRoom.java b/src/org/cpsolver/exam/model/ExamRoom.java
index 8a8b0bfd..39fd7218 100644
--- a/src/org/cpsolver/exam/model/ExamRoom.java
+++ b/src/org/cpsolver/exam/model/ExamRoom.java
@@ -44,6 +44,7 @@ public class ExamRoom extends ConstraintWithContext<Exam, ExamPlacement, ExamRoo
     private String iName;
     private int iSize, iAltSize;
     private Double iCoordX, iCoordY;
+    private boolean iHard = true;
 
     /**
      * Constructor
@@ -79,6 +80,11 @@ public ExamRoom(ExamModel model, long id, String name, int size, int altSize, Do
         }
     }
     
+    public void setHard(boolean hard) { iHard = hard; }
+    
+    @Override
+    public boolean isHard() { return iHard; }
+    
     private Map<Long, Double> iDistanceCache = new HashMap<Long, Double>();
     /**
      * Distance between two rooms. See {@link DistanceMetric}
@@ -226,6 +232,7 @@ public ExamRoomSharing getRoomSharing() {
      */
     @Override
     public void computeConflicts(Assignment<Exam, ExamPlacement> assignment, ExamPlacement p, Set<ExamPlacement> conflicts) {
+        if (!isHard()) return;
         if (!p.contains(this)) return;
         
         if (getRoomSharing() == null) {
@@ -243,6 +250,7 @@ public void computeConflicts(Assignment<Exam, ExamPlacement> assignment, ExamPla
      */
     @Override
     public boolean inConflict(Assignment<Exam, ExamPlacement> assignment, ExamPlacement p) {
+        if (!isHard()) return false;
         if (!p.contains(this)) return false;
         
         if (getRoomSharing() == null) {
@@ -259,7 +267,7 @@ public boolean inConflict(Assignment<Exam, ExamPlacement> assignment, ExamPlacem
      */
     @Override
     public boolean isConsistent(ExamPlacement p1, ExamPlacement p2) {
-        return (p1.getPeriod() != p2.getPeriod() || !p1.contains(this) || !p2.contains(this));
+        return !isHard() || (p1.getPeriod() != p2.getPeriod() || !p1.contains(this) || !p2.contains(this));
     }
 
     /**