Smart Door Lock Types Compared: Deadbolt vs Mortise vs Retrofit Locks

Choosing smart locks for hundreds of doors is different from buying one. A product may offer excellent electronics and app features yet remain unsuitable because its lock body does not match the door preparation.

The three smart door lock types most B2B buyers encounter are smart deadbolt locks, smart mortise locks, and retrofit smart locks. They solve different installation problems. Understanding their mechanical requirements helps B2B buyers avoid costly rework.

This guide compares their installation requirements and provides a supplier-ready checklist.

Main Types of Smart Door Locks Explained

Electronics determine access methods; mechanical architecture determines how the lock fits the door and engages the frame. Confirm mechanical fit first.

Type	Mechanical arrangement	Common applications	Main compatibility concern
Smart deadbolt lock	Motorized deadbolt installed in a bored door preparation, often separate from the lever	North American homes, apartments, selected rental properties	Backset, cross-bore and edge-bore diameters, door thickness
Smart mortise lock	Integrated lockcase fitted into a pocket cut into the door edge; often operates with a lever and cylinder	Residential entrance doors, hotels, offices, regional project installations	Lockcase dimensions, spindle/cylinder centers, faceplate, door construction
Retrofit smart lock	Adds electronic operation to compatible existing hardware, often from the interior side	Renovations, rental upgrades, projects that need to retain keys or exterior trim	Existing cylinder/thumbturn design, mounting clearance, operating torque

These categories are not mutually exclusive in every product catalog. “Retrofit” describes an upgrade method rather than one universal lock mechanism; a retrofit device may operate an existing deadbolt or cylinder used with a mortise lock.

A simple purchasing rule

Choose the lock body according to the door preparation already installed or specified, not according to the keypad, fingerprint reader, or wireless protocol shown in a promotional image.

Smart Deadbolt Locks: Common Applications and Requirements

A smart deadbolt lock is often the easiest starting point for projects built around North American bored-lock preparations. The powered assembly typically turns a deadbolt through a hole drilled across the door face. The bolt projects from the door edge into the strike mounted on the frame.

For many US residential deadbolts, familiar backset options are 2-3/8 inches (60 mm) and 2-3/4 inches (70 mm). A 2-1/8-inch (54 mm) cross bore, approximately 1-inch (25 mm) edge bore, and door thickness around 1-3/8 to 1-3/4 inches (35–44 mm) appear in certain manufacturers' installation templates. These are examples, not a universal smart-lock specification. Other locks accept different bore sizes or thicker doors; check the exact SKU.

An adjustable latch can reduce distributor inventory across 60 mm and 70 mm backsets—but verify the supplied component and installation sheet.

Confirm bore size, backset, rectangular or drive-in faceplate, strike alignment, and clearance around the keypad and battery housing.

A deadbolt is not automatically a suitable replacement for an integrated mortise set. Converting one architecture to another may require patching old holes or replacing the door entirely.

Figure 2: Deadbolt Backset and Bore Measurement illustrates the locations buyers should photograph and measure.

Smart Mortise Locks: Mechanical Structure and Installation

A smart mortise lock uses a lockcase recessed into a rectangular pocket in the door edge. Depending on the design, it may combine a latch, deadbolt, handle follower, cylinder interface, and electronic actuator. This makes mortise systems attractive for applications where a complete handle-and-lock assembly is expected.

Externally similar mortise lockcases can have incompatible dimensions. For example, an ASSA ABLOY configuration has a 60 mm backset and 72 mm handle-to-cylinder center distance. A matching backset alone does not guarantee a fit.

When evaluating a smart mortise lock, request a dimensioned drawing that identifies:

• Backset: distance from the faceplate/door-edge reference to the specified follower or cylinder axis.

• PZ or center-to-center distance: vertical distance between the lever spindle center and cylinder center, when that configuration applies.

• Lockcase envelope: overall depth, height, and body thickness, excluding or identifying faceplate dimensions.

• Faceplate: height, width, thickness, radius, and screw-hole positions.

• Operating components: spindle square size, latch direction, deadbolt position, cylinder type, and cable route.

Timber, hollow-metal, aluminum-profile, and fire-rated doors may require different reinforcement or factory preparation. Check frame-strike alignment.

For hotels and commercial projects, verify egress and applicable fire-door approvals. Wireless features do not make an incompatible door assembly compliant.

Figure 3: Mortise Lockcase Measurement shows how to distinguish backset, PZ, case height, and case depth.

Retrofit Smart Locks: When to Keep Existing Hardware

A retrofit smart lock can be a practical alternative when a building already has dependable mechanical hardware. Rather than removing the entire lockcase, the retrofit unit usually adds motorized operation to a supported interior thumbturn, key, cylinder, or deadbolt mechanism.

This can preserve existing keys and exterior trim—a useful option for occupied apartments, rentals, and renovations.

Nevertheless, retrofit does not mean universal. A European cylinder retrofit may require a specific cylinder profile, enough cylinder projection for the mounting plate, and clearance between the smart-lock housing, door frame, and lever. If a key stays inserted inside, buyers should check whether the cylinder permits safe operation with an outside key. Some manufacturers call this an emergency function.

Check operating resistance: a stiff cylinder or misaligned multipoint mechanism can overload the motor. Lever-lift doors may still require users to lift the handle first.

For large orders, test a representative sample of each existing lock variant, rather than assuming that one successful retrofit proves compatibility across an entire property portfolio.

Door Thickness, Backset, Door Handing and Lock Body Dimensions

Many installation failures originate in missing measurements or incorrect reference points.

1. Door thickness

Measure the finished door leaf from one face to the other at the proposed mounting height. Record the dimension in millimeters and note unusually thick decorative panels, bevels, or reinforcing plates. Then compare it with the model's allowed door-thickness range and mounting hardware length.

Figure 1: Door Thickness Measurement identifies the two finished faces.

2. Backset and drilled holes

For a bored deadbolt, measure horizontally from the door edge to the center of the cross bore, not to the outside of the keypad. For a mortise design, use the reference axis specified on the lockcase drawing; also provide the position of the existing handle and keyhole.

Record the face-bore diameter, edge-bore diameter, and spacing from nearby handles. Never convert a rough tape measurement into a confident “standard size” without checking the actual door.

3. Mortise case and faceplate

For a replacement mortise lock, remove the existing lockcase only when safe and authorized. Measure case depth and height separately from the faceplate, plus the case thickness, screw positions, latch/deadbolt layout, spindle size, and cylinder centerline. Provide ruler photographs or a marked technical sketch.

4. Door handing and swing

Stand on the exterior or unsecured side of the closed door. State which side contains the hinges and whether the door swings inward (away from you) or outward (toward you). For North American hardware schedules, the common shorthand is LH, RH, LHR, and RHR. Because some markets and manufacturers use different naming conventions, written descriptions and photographs are safer than abbreviations alone.

Figure 4: Door Handing Identification illustrates all four arrangements. Check whether the selected lock is reversible or requires an ordered handing configuration.

Choosing Smart Locks for Different Regional Markets

Regional preferences are screening guides, not universal installation standards.

United States and Canada. Bored deadbolts are especially relevant for residential retrofit and new construction. Ask for inch-and-millimeter drawings, 60/70 mm backset options, and the exact bore and thickness requirements. For multifamily or commercial buildings, separately assess fire and egress rules.

United Kingdom and continental Europe. Many projects involve mortise, euro-profile-cylinder, or multipoint arrangements. Buyers should specify PZ, backset, cylinder profile, door material, and whether an existing multipoint mechanism must be retained. Retrofit devices may work well for compatible cylinders, but clearances and emergency-key behavior require checking.

Southeast Asia and the Middle East. Residential, hotel, and developer projects often mix timber, metal, aluminum-profile, mortise, and specialized entrance doors. Therefore, importers should collect door schedules by project and model rather than importing one “universal” lock body for an entire region.

Where a project involves fire-rated doors, escape routes, or managed accommodation, involve the door supplier and local code professional before finalizing hardware. Compliance depends on the assembled door system and intended use, not merely on the smart lock's electronics.

Pre-Order Door Compatibility Checklist

Before ordering, send a door specification package so mechanical compatibility is confirmed before branding or app customization.

Item to confirm	What to send to the manufacturer
Door construction	Timber, steel, aluminum-profile, composite, fire-rated, or other
Finished door thickness	Measurement in mm, with a photo at lock height
Existing lock architecture	Deadbolt, mortise, multipoint, or retrofit candidate
Backset and bore sizes	Exact mm/in measurements and marked centers
Mortise dimensions	Case depth/height/thickness, faceplate, PZ, spindle and cylinder type
Door handing	Hinges left/right, opens inward/outward, exterior-side photo
Door and frame clearance	Trim, lever, glass, frame, seal, and strike locations
Site and regulatory needs	Market, door use, egress/fire requirements, environmental exposure
Project information	Required quantity, finish, access methods, connectivity, and timeline

Recommended sample process: First, compare the door drawing against the manufacturer's installation template. Second, fit a physical sample to a representative door without irreversible alterations, where possible. Third, test manual and electronic locking, frame alignment, emergency exit operation, and repeated use. Only after approval should the importer authorize bulk production or custom branding.

Send Us Your Door Specifications

Comparing smart door lock types for your product range or project? ChuYun Smart can review the specifications provided and discuss suitable configurations.

Send us your door thickness, backset, lockcase dimensions, door handing, target country, quantity, and clear photos of the existing lock and door edge. If available, include the door manufacturer's CAD drawing or drilling template.

Send Us Your Door Specifications — and start with mechanical compatibility before committing to your next smart lock order.