Most interior doors are prepped with a single boor hole.
Standard door handle hole size and position.
Installers typically drill the hole centered 36 inches above the floor if not specifically instructed to do so differently.
Through the edge of the door there is a 1 cross bore that extends from the edge of the door through the bore hole.
It is more important that your door handles be consistent than that they match the standard door handle height.
This creates a more harmonious appearance.
The requirements of bs 8300 provide for a door knob to be between 800mm 1050mm 31 5 41 5 inches from a finished floor.
Most of the current locks require the standard 2 1 8 bore.
Their position should be between 900mm 1050mm 35 5 41 5 inches above the floor.
If one wants to replace their locks on doors that have smaller diameter holes there are 2 options.
Many older doors had bores that were been smaller.
Lock bore the diameter of the hole for the lock body.
The international building code has established doorknob height between 34 and 48 inches above a finished floor.
If they are more than inch off the standard height you will want to match all of the pre existing door handle heights in your home.
Measure your existing door knobs from the floor up.
The standard bore is 2 1 8.
Generally the knobs should be of a free moving slide action.
Measure from the center of the door knob hole to the edge of the doorway to find the size of the door set.
The standard sized bore hole is 2 1 8 in diameter.