One other thing that can be considered for window security is the fitting of a security film to the glass. The film is virtually undetectable but will hold the glass in place against a brick or other object thrown at the glass.
The film comes in various formats - mirror, bronzed or coloured, and in varying thicknesses dependng upon its purpose. Its main use is to make glass safe in areas where people could fall against the glass and seriously injure themselves. The bronzed and coulored ranges are usually to help cut glare and heat coming into a building as well as security and safety.
The films can be fitted by the end user, but can be problematical - as with anything there is a knack to fitting and it may be better to ask our staff to install it for you.