If at all possible, if you are building or renovating or know someone who is please think about installing bird proof glass which has lines through it. Fabulous information can be found here:
These lines cannot be seen by the human eye, but they are definitely seen by the birds. Decals may also be used which are less expensive but perhaps not as appealing to the human eye or building structure. More sources of information can be found here:
What we have used actually, is strings of amber (orange) beads hooked onto the window by self-adhesive plastic suction cups. They look fabulous to the eye and can be taken down in the Winter time. We have placed the strings 5cm apart. Very effective – no more bird strikes!!!
These sites referenced above also explain in depth how we are all impacting our bird population based on where we choose to place our structures and the building materials selected.