Custom Locking: The secondary glazed sliding window system can be fitted with the same multi point ventilation lock as used on conventional centre lock sliding windows (illustrated on this page). Using this multi point key lock with laminated glass would significantly improve home security as well as reduce the sound intrusion and heat transfer. Hinged Doors: Hinged entry, French and Bi-folding doors can be fitted with thicker glass including insulating glass. Sliding Doors: Can be fitted with very thick laminated glass (up to 10.38mm) or 19mm insulating glass to improve the numbers. There is no value working on the windows and ignoring the doors. Test reports can be supplied for both sliding and hinged doors.