As the before photo shows these windows where damaged by weather exposure.The clients found that the west facing windows where difficult to maintain.So we removed all internal glazing and timbers.We then inserted new sliding windows and the visible timbers where covered with weather proofed flashings with the same finish as the new windows.The after picture shows one of the optional security grills fitted,you may also have  flyscreens only, or  stainless steel meshed security screens.