Mortise locks are specified under ANSI/BHMA A156.13 (Mortise Locks & Latches); bored cylindrical locks fall under A156.2, and their cylinders and keying under A156.5. A complete specification names the lock function, grade, backset, strike, lever or knob trim, and keying — with Grade 1 selected for commercial and high-traffic multifamily openings.
The lock is where a door schedule succeeds or fails a security and accessibility review. Two construction types dominate — mortise and cylindrical (bored) — and they are not interchangeable line items. They have different strengths, different install requirements, different cost, and different function ranges. Choosing the wrong one, or the wrong function within it, produces a door that either fails an inspection, frustrates residents, or has to be reworked after the frames are already prepped. This guide separates the two constructions, lists the standard functions, and covers the grade, backset, keying, and ADA confirmations that keep a lock schedule correct.
Mortise vs. cylindrical construction
Mortise locks (A156.13). A mortise lock houses a complete lock case inside a rectangular pocket — the mortise — cut into the edge of the door. Because the case is large, a mortise lock supports a wide function range, integrates a deadbolt in the same case, accepts heavier trim, and generally outlasts a bored lock on high-cycle openings. Mortise locks are the specification of choice for building entries, unit entries on higher-grade projects, and any opening where security and longevity justify the higher install labor.
Cylindrical (bored) locks (A156.2). A cylindrical or tubular lock installs through two bored holes — a large cross-bore through the face of the door for the lock body and a smaller edge-bore for the latch. This is faster and cheaper to install and covers the majority of interior and moderate-traffic openings. Grade 1 cylindrical locks are entirely appropriate for commercial and multifamily common doors; the trade-off versus mortise is function range and ultimate durability, not baseline security at the same grade.
The install decision cascades into the door and frame prep, so it must be locked before doors are ordered. A door bored for a cylindrical lock cannot accept a mortise case without a new door.
Lock functions
Function defines what the lock does — which side locks, which side always allows egress, whether a key is involved. The core functions on a multifamily and commercial schedule:
| Function | Behavior | Typical application |
|---|---|---|
| Passage | Latch only, no lock; both levers always free | Closets, hallways, non-locking interior doors |
| Privacy | Locked from inside by push-button/turn, emergency release outside | Unit bedrooms and bathrooms |
| Entry | Key outside, thumbturn/button inside; egress always free | Unit entry doors |
| Storeroom | Outside lever always locked, key retracts latch; inside always free | Storage, electrical, mechanical, IT rooms |
| Classroom | Key locks/unlocks outside lever; inside always free | Amenity, office, and controlled common rooms |
Egress is the non-negotiable rule: the inside lever must always retract the latch without a key, tool, or special knowledge on any occupiable space. Storeroom and classroom functions preserve free egress by design; confirm no schedule specifies a double-keyed (key-both-sides) function on an egress door, which is a code violation on occupied spaces.
Grade, backset, and strike
A156.13 and A156.2 grade locks by cycle and strength testing into the familiar Grade 1 / Grade 2 / Grade 3 tiers. Grade 1 is specified for commercial and high-traffic multifamily — building entries, amenity, corridor, and stairwell doors. Unit entries are commonly Grade 1 or Grade 2; low-traffic interior unit doors may drop to Grade 2. When a specific cycle figure is not verified for a given model, cite the standard family and grade rather than inventing a number.
Backset — the distance from the door edge to the center of the bore or spindle — is typically 2-3/4" on commercial openings and 2-3/8" on many residential ones, and must match the door prep and strike. The strike (and its reinforcement in the frame) is part of the lock’s security rating; a Grade 1 lock into an unreinforced strike does not deliver Grade 1 resistance. Confirm strike type and frame reinforcement alongside the lock grade.
Keying, cylinders, and ADA operability
Cylinders and keying are governed by A156.5 (Cylinders & Input Devices). Multifamily buildings need a master key system that gives property management single-key access while preserving individual unit key control, so the cylinder and keyway must be compatible with the specified master key system before locks are ordered. Rekeyable cylinders, which let management rekey a unit between tenancies without replacing the lock, are increasingly standard and must be confirmed as compatible at specification, not discovered at turnover.
On accessibility: the ADA Standards require operable hardware on accessible units and accessible common areas to work without tight grasping, pinching, or twisting of the wrist. Levers satisfy this; round knobs do not. Any accessible opening — and, in active-adult and universal-design projects, every opening — must carry lever trim regardless of whether the lock case is mortise or cylindrical.
What Innergy confirms and how we spec locks
On Innergy projects, every opening on the lock schedule gets a confirmed construction type (mortise or cylindrical), a named function, and a grade matched to traffic — Grade 1 on common and high-traffic doors, stepping down only where use genuinely justifies it. We verify backset and strike reinforcement against the door and frame prep before doors are ordered, since a construction or backset change after prep means new doors.
We confirm the cylinder and keyway against the project’s master-key and rekeyable system with the property manager, and we confirm lever trim on every accessible opening for ADA operability. Where a door also carries a closer or panic device, we coordinate the lock function so egress is never defeated. This lock discipline sits inside the broader schedule covered in our door hardware specification guide for multifamily construction.
Related door hardware specifications
The lock is one component of the opening. The hinges that carry the door are covered in our door hinge specifications, the control that closes it in our door closer specifications, and the operable trim itself in lever, knob, and handleset specifications. On egress and fire-rated openings, the locking function must coordinate with the exit and panic device specifications.
Door hardware falls in our Division 8 openings, mirrors, and shower doors scope for multifamily and commercial projects. To have a coordinated lock and hardware schedule reviewed before procurement, contact us and we respond within one business day.