How to Determine Door Handing (LH, RH, LHR, RHR) for Commercial Hardware Projects
Introduction
Incorrect door handing is one of the most common causes of hardware delays, field modifications, and return shipments on commercial projects. When specifying mortise locks, exit devices, electrified trim, or automatic operators, handing may need to be confirmed before ordering depending on the hardware type and manufacturer requirements. In many applications it is critical, while in others it is non handed or application specific.
In access control environments, an incorrect handing can affect configuration, trim selection, and overall installation efficiency.
This guide explains the industry standard method for determining door handing on commercial openings and how to correctly identify LH, RH, LHR, and RHR in the field.
The Industry Standard Method for Determining Handing
To determine handing correctly:
- Stand on the secure (keyed) side of the door.
- Identify the hinge location.
- Observe the direction the door swings.
From that position:
- Hinges on the left = Left Hand
- Hinges on the right = Right Hand
- Door swings toward you = Reverse
- Door swings away from you = Standard
This method applies to most commercial hollow metal and aluminum storefront openings.
Standard Handing Definitions
Left Hand (LH)
- Stand on secure side
- Hinges on left
- Door swings away from you
Common in interior office applications.
Right Hand (RH)
- Stand on secure side
- Hinges on right
- Door swings away from you
Often used in corridor openings.
Left Hand Reverse (LHR)
- Stand on secure side
- Hinges on left
- Door swings toward you
Common on exterior commercial doors.
Right Hand Reverse (RHR)
- Stand on secure side
- Hinges on right
- Door swings toward you
Frequently seen on storefront and perimeter openings.
Inswing vs Outswing Considerations
Most commercial exterior doors are outswing for life safety and weather resistance. These typically fall under LHR or RHR configurations.
Interior doors are commonly inswing and will typically be LH or RH.
Handing often affects selection and configuration for:
- Electrified mortise locks
- Motorized panic bar kits
- Electric strikes (application type and alignment to the latch or bolt prep)
- Automatic door operators (push vs pull side application)
If you are specifying hardware for electrified openings, confirm handing before selecting components.
For deeper guidance on related hardware, see:
- Electrified Mortise Locks Explained: Types, Functions, and Applications
- Choosing the Right Exit Device: Rim, Mortise, or Vertical Rod? (2025 Guide)
- Fail Safe vs. Fail Secure Locks: Differences, Uses, and Best Applications
Field-Reversible Hardware: When Handing Becomes Less Critical
Not all electrified hardware requires strict factory specified handing. Many modern electrified mortise locks are field reversible, meaning the handing can be adjusted during installation rather than at the time of order.
A strong example is the Command Access ML180 24V Electrified Mortise Lock (EU Function).
This model is designed for flexibility in access control retrofits and new installations. Because it is field reversible, installers can configure the handing on site to match LH, RH, LHR, or RHR conditions. This significantly reduces ordering risk and helps prevent project delays caused by incorrect handing selection.
With field reversible electrified mortise locks:
- The chassis supports multiple handing configurations
- The latch bolt orientation can be adjusted
- Electrified components remain compatible across swing directions
- Inventory management becomes simpler for contractors and distributors
However, even with field reversible hardware, installers must still confirm:
- Door swing (inswing vs outswing)
- Secure side orientation
- Frame prep and strike alignment
- Power routing method
Field reversible products reduce specification risk but they do not eliminate the need for proper opening verification.
For contractors looking for a flexible electrified mortise solution, you can view the product here:
Command Access ML180 EU CH 24V Electrified Mortise Lock
Field Verification Tips for Contractors
To avoid ordering errors:
- Always identify the secure side first
- Confirm swing direction from that position
- Visually confirm hinge barrel location
- Verify against door schedule when available
- When retrofitting, confirm that the frame has not been modified
On retrofit electrification projects, incorrect handing can require reordering of trim, latch retraction kits, or operator arms.
Proper field verification saves labor and prevents project delays.
Final Notes
Door handing is foundational to commercial hardware specification. It directly supports proper selection of electrified hardware, exit devices, and access control components. If you are planning a full system upgrade, reviewing Types of Electronic Locking Hardware for Commercial Properties | 2025 Guide can help align handing with the correct hardware category. Whether installing mechanical locks or integrating full access control systems, confirming LH, RH, LHR, or RHR at the beginning of the project prevents unnecessary rework.
When in doubt, confirm with door schedules, architectural drawings, or physical inspection before placing hardware orders.