Exterior Door Trim and Handles Explained

Exterior trim is the outside operating hardware used with an exit device, and the right choice depends on whether a door should allow no entry, key-controlled entry, or free entry from the outside. The most common functions are exit only (EO), dummy trim (DT), night latch (NL), thumb piece (TP), knob or lever (K or L), turn lever (TL), and blank escutcheon (BE).

Knowing if your exterior door requires trim and, if so, what type of trim can be a complicated problem for building owners. For some projects the manufacturer's function number is listed, but for others there may only be a description, making the decision more difficult. In addition, there are many operating functions available to choose from, in several finishes.

Some of the most frequently used are (EO) exit only, (DT) dummy trim, (NL) night latch, (TP) thumb piece, (K) or (L) knob or lever, (TL) turn lever, or (BE) blank escutcheon. Generally, however, BHMA Certified hardware is recommended because it has been tested and approved based on standards for its classification or grade. To help make the selection of exterior trim and handles easier, you can find a description of the most common types below.

Exit Only Devices

Exit devices are designed to automatically release when the pad or bar is pushed from the inside. They are sold as exit only devices and always mount on the inside of the door with options for exterior trim. You can choose to provide no entrance from the outside by ordering an (EO) exit only device, without handles or locks. You would have no available entry point unless someone opens the door from the inside. This application works well for back doors that are not always watched, or as a deterrent in areas that are prone to vandalism.

Non-Fire Rated

Non-fire rated exit devices can be "dogged" or left in the unlocked position. While "dogged", door closers keep the door closed, but the latching mechanism is not functional.

Dummy Trim

Dummy trim (DT) can be used on the outside as a pull handle. It looks like a lever but has no movement. Dummy trim can be used on the inactive leaf of a pair of doors where one door may not need to lock, but it's aesthetically important to match the locking trim on the active door.

Night Latch

Exit devices that require latching and an optional entry point from the exterior can be ordered to include key functions. One of the keyed functions is a Night Latch (NL), described as always locked outside except when a key is used to retract the latch bolt. When you remove the key the latch returns and the door is locked again.

Thumb Piece, Knob, or Lever

Thumb piece (TP) function is described as being locked or unlocked with a key, and a thumb type latch control to open. You can unlock the door from the outside, remove the key, and the door remains unlocked until you use the key again to lock it. Knob (K) or lever (L) is the same function as TP, but offers a knob or lever that complements the style of levers or knobs used in the rest of the project.

Note: The TP and knob trims do not meet ADA requirements.

See our guide to ADA compliant commercial doors for more on accessible hardware.

Turn Lever

Turn lever (TL) can be unlocked or locked by use of a key. You may have seen this type of door with vertical rod devices. When unlocked, the turn lever will retract the vertical rods.

Blank Escutcheon

Blank escutcheon (BE) has no key control. The operating trim, thumb piece, knob, or lever is operable at all times. Escutcheons and roses cover the lock installation screws and hardware preps on the door. An escutcheon is usually an elongated plate. A rose is the round cover.

Contact Mills & Nebraska to learn more about our exterior door trim options.