We were looking for something like this for our office not so long ago, too. Safety film is a really good solution, especially if you want to protect the windows without spoiling the appearance. Here at the link there is information about safety film for window, they are just engaged in selection and installation, so you can consult and immediately order services totalserviceny.com

Thanks for the reply! How long does it take to install such a film? And how much does it really protect the windows, especially from impacts?