Residential building in the context of "Istanbul Sapphire"

A door handle or doorknob is a handle used to open or close a door. Door handles can be found on all types of doors including: exterior doors of residential and commercial buildings, internal doors, cupboard doors and vehicle doors. There are many designs of door handle, depending on the appropriate use. A large number of handles, particularly for commercial and residential doors, incorporate latching or locking mechanisms or are manufactured to fit to standardised door locking or latching mechanisms.

The most common types of door handle are the lever handle and the doorknob. Door handles can be made out of a plethora of materials. Examples include brass, porcelain, cut glass, wood, and bronze. Door handles have been in existence for at least 5000 years, and its design has evolved since, with more advanced mechanism, types, and designs made.