How to Determine Door Opening Direction:
LH vs RH Made Simple
Whether for personal use or bulk purchasing, if the door opening direction is specified incorrectly when placing an order, it can cause serious problems.
This article will explain in detail how to correctly determine door opening direction.
I. Handing for a Single Door
1) Confirm where the person is standing (viewpoint)
When communicating with a manufacturer or supplier, the first thing we must do is confirm that both sides are using the same point of view to determine the door swing.
For example, if you are viewing the door from outside the room, while the other party is viewing it from inside the room, then the opening direction you describe will be completely opposite.
As shown in the image above:
If you are standing outside the room, the door is in-swing, left-hand.
However, if you are standing inside the room, the same door becomes in-swing, right-hand.
2) Correct way to use LH and RH
Under normal circumstances:
LH = Left Hand
RH = Right Hand
However, since some people interpret “left” and “right” based on personal habits, to avoid confusion we always define LH and RH by the hinge location.
As shown in the image above:
In-swing LH means the hinges are on the left side
In-swing RH means the hinges are on the right side
In short: the side where the hinges are located determines LH or RH.
3) How to describe in-swing and out-swing
If the door swings toward the inside of the room, it is called in-swing or inside open.
If the door swings toward the outside of the room, it is called out-swing or outside open.
II. Handing for a One-and-a-Half Door (Primary + Secondary Leaf)
After understanding the opening direction of a single door, sometimes a room requires a one-and-a-half door. How should this be defined?
As shown in the image above:
The opening direction of a one-and-a-half door follows the same rules as a single door.
The smaller leaf is usually fixed and rarely opened, and its swing direction always matches the main (active) door.
If the main door is in-swing, the smaller door is also in-swing
If the main door is out-swing, the smaller door is also out-swing
Therefore, when describing the opening direction of a one-and-a-half door to a supplier, you can simply treat it as a single door.
III. Handing for Double Doors
The opening direction of double doors follows the same logic as a one-and-a-half door, as shown in the image below.
Even though it is a double door, there is still a primary door and a secondary door.
The primary door is the one that is used most frequently
The secondary door is usually kept closed
Therefore, double doors still have a defined opening direction.
In the example shown above, the doors are in-swing LH (from the outside view).
Why must the opening direction be clearly defined?
Because hinge mortises are typically pre-machined on the door slab. If the opening direction is wrong, the entire door set will be incorrect.
IV. What if the handing cannot be confirmed?
In some cases, the jobsite conditions make it hard to confirm handing in advance. How can we solve this?
It’s simple: use a different type of hinge, as shown in the diagram.
This hinge type has a design where the two leaves overlap when the door is closed, which helps reduce the gap between the door and frame.
So there is no need to mortise (route) hinge pockets in the door slab and frame.
After the customer receives the door, they can decide the opening direction during installation.
Summary
With traditional hinges, hinge pockets must be mortised in the door slab and frame ahead of time, so the handing must be confirmed in advance.
But with this newer hinge style, no hinge pockets are required, so the handing does not need to be fixed in advance—the customer can decide the swing direction during installation.
Any quesions you can contact with us anytime. John@yudoors.com
