How to Determine Commercial Door Handing
, by United Doors and Locks, 5 min reading time
Handing is decided from the outside of the door, and getting it wrong means returning parts. LH, RH, LHR and RHR, explained with the checks that catch mistakes.
Handing is the most common reason a hardware order comes back. It takes ten seconds to determine and, done wrong, it costs a return, a delay, and sometimes a door that has already been prepped for the wrong hardware.
Start from the outside
Every handing convention begins the same way: stand on the outside of the door. The outside is the secure side — the side you need a key to get in from. For an exterior door that is the street. For an office, it is the corridor. For a mechanical room, it is whichever side the public can reach. For a closet, it is the room the closet opens into.
Get this wrong and every answer that follows is reversed, which is exactly how a right-hand door ends up ordered as a left.
The four hands
With your back to the outside, note which edge the hinges are on and which way the door swings.
- Left Hand (LH): hinges on your left, door swings away from you.
- Right Hand (RH): hinges on your right, door swings away from you.
- Left Hand Reverse (LHR): hinges on your left, door swings toward you.
- Right Hand Reverse (RHR): hinges on your right, door swings toward you.
That is the whole system. Hinge side gives you left or right; swing direction gives you regular or reverse.
Why reverse matters more than left or right
Left and right affect which way a lever is oriented and which side a strike is prepped. Reverse changes the bevel of the door edge and, on many devices, the internal handing of the mechanism.
A door that swings toward you from the outside is an outswing door, and outswing doors carry two consequences worth remembering. The hinge barrels are exposed on the insecure side, which is why exterior outswing doors should use non-removable pin hinges such as the BB5 NRP ball bearing hinge. And the door edge is bevelled the opposite way, which is where the term reverse bevel comes from.
Hardware that cares, and hardware that does not
Not every item on the schedule needs a hand.
Needs handing: mortise locks, most closers when the mounting is specified, overhead stops and holders, electric strikes, flush bolts, and lever trims with a defined orientation. The ML1300 Series mortise lock is handed because the latch bolt bevel and the lock case functions are built for one direction.
Often non-handed: cylindrical locks with reversible levers, ball bearing hinges such as the H4545 Series, and many modern rim exit devices. The Accentra 2100 Series rim exit device is non-handed by design, which is one reason rim devices are forgiving to order.
When a product is non-handed, you still need the handing for the rest of the opening. The hinge may not care, but the closer bracket and the strike prep will.
Two checks that catch mistakes
The hinge-knuckle check. Stand outside. If you can see the hinge knuckles, the door swings toward you and it is a reverse hand. If you cannot see them, it swings away and it is a regular hand. This is faster than reasoning about swing direction and it is difficult to get wrong.
The closer check. A surface closer mounted on the side you are standing on, with the arm visible, usually means you are on the pull side. On an outswing exterior door, the closer is normally inside, out of the weather — another way to confirm which side is which.
Pairs of doors
A pair is handed by its active leaf, the one with the lock. Stand outside and identify which leaf you would pull to walk through; that leaf's hinge side and swing give you the hand. The inactive leaf takes flush bolts or a vertical rod device, and if the pair has no mullion, the astragal and coordinator have to suit the same hand.
Write it down at the opening
Handing errors almost always happen away from the door, when somebody reconstructs the opening from memory at a desk. Mark the hand on the frame in pencil while you are standing there, or photograph the open door from the outside so the hinge side and swing are both visible in the frame.
If you are working from a set of drawings and the hand is not called out, send us the plan. We will read the handing off the door schedule before anything ships.