Bi-fold windows have sashes that are hinged alternatively allowing them to fold out of the way on the side. They are typically used in kitchens were they act as a servery to an outdoor entertaining area. A wider sill can be fitted if desired.
Windoor typically uses high quality Brio and Centor hardware for its track and sliding mechanisms. If you would like more information on their systems follow the link to www.brio.com.au or http://www.centor.com.au/
To view images of Bi Fold Windows click here
To download a tech sheet for bi fold windows click here