Introduction
Before comparing fingerprints, PIN codes, Wi-Fi, or app platforms, answer a more physical question: can the lock actually mount to this door and operate the existing latch or lock body? A product photo rarely shows the dimensions that decide that answer.
To measure a door for a smart lock, identify the lock route first, then record door thickness, backset or cylinder position, cross bore, edge bore or lock case, lock spacing, flat mounting width, strike and handing, and interior clearance. Photograph the door faces, edge, existing hardware, and frame, then compare the complete record with the exact model’s installation template.
This sequence is useful for a single replacement door, but it matters even more when a distributor, builder, rental operator, or private-label team must repeat the installation across several door types. The goal is not to collect numbers for their own sake; it is to create enough evidence for a clear fit, alternate lock route, or technical review.
Principaux enseignements
- A complete smart-lock measurement record has more than one dimension; at minimum, include the door route, thickness, lock centreline, bore or lock case, strike, and interior clearance.
- Measure the structural lock rail and the actual existing hardware, not only the decorative face of the door or the outside edge of an escutcheon.
- A 60 mm or 70 mm backset, a 35 mm or 44 mm thickness, or a 54 mm bore can be common reference values without proving that a specific model will fit.
- If the door is mortise, Euro-cylinder, narrow-stile aluminum, glass, sliding, rim-mounted, or visibly irregular, stop using a standard bored-deadbolt checklist and switch to the correct product route.
- For repeat projects, one completed sample form is not enough; record every door family and preserve the approved measurements with the model and hardware revision.
Start by Identifying the Lock Route
The first measurement is not a number. It is the hardware family you are trying to replace or automate.
Look at the door edge and both faces with the door open. A round bored hole with a separate latch points to a bored deadbolt or tubular-latch route; a long rectangular case in the edge points to a mortise route; a Euro profile cylinder, rim case, narrow aluminum stile, glass clamp, or surface-mounted body requires its own compatibility logic.
| What you see | Likely route | Measure next | Stop and escalate when |
|---|---|---|---|
| Round face bore and separate edge latch | Bored deadbolt or tubular latch | Thickness, backset, bore, edge bore, lock spacing, strike, clearance | The bore, backset, or trim is outside the model template |
| Long rectangular case in the door edge | Mortise or lever lock | Case height/depth, faceplate, spindle, cylinder, door thickness | You cannot identify the lock case or the replacement body |
| Euro profile cylinder with a retaining screw | Euro-cylinder retrofit or cylinder replacement | Inside/outside cylinder dimensions, door thickness, projection, escutcheon, clearance | The cylinder is unusual, anti-snap, protected, or not removable |
| Narrow aluminum stile or framed glass | Narrow-stile or glass-door solution | Stile/frame width, glass thickness, lock body, clamp/cutout, mounting area | The lock body would cover glass, frame joints, or unsupported material |
| Surface-mounted case or rim lock | Rim or surface-mounted route | Case size, mounting surface, strike, frame, cable path | The face is uneven or the rim case cannot sit square |
| Sliding or multi-point door | Specialty or retrofit route | Lock position, cylinder/handle system, travel, interior clearance | The product document does not explicitly cover the mechanism |
Do not force every door into the standard deadbolt route because it is the most familiar. This early classification prevents you from collecting the wrong measurements and then treating a technically complete form as proof of compatibility.
Measure the Door in a Fixed Order
Once the route is known, use the same order every time. The order below moves from the door itself to the lock geometry, then to the frame and operating space.
1. Door thickness at the lock rail
Measure the structural slab where the lock mounts. On a hollow, reinforced, metal, composite, or decorative door, the lock rail may not have the same build-up as the rest of the slab.
Record the bare slab thickness in millimeters and inches. List permanent plates, overlays, molding, weather seals, or trim as separate layers, because the manufacturer’s thickness range may describe the slab rather than every layer around the assembly.
For a deeper explanation of minimum/maximum ranges, screws, tailpieces, spacers, and thick-door accessories, see the site’s smart lock door thickness guide.
2. Backset or cylinder reference point
For a bored deadbolt or tubular latch, measure from the door edge to the centre of the relevant bore or spindle line. For a Euro-cylinder or mortise lock, use the reference point defined by that lock family, often the centre of the retaining screw or cylinder position.
Do not measure to the edge of the hole, rose, escutcheon, or decorative plate. The site’s smart lock backset guide explains the edge-to-centre measurement and why 60 mm and 70 mm are only candidate values until the full lock format is confirmed.
3. Cross bore, edge bore, or lock case
On a bored door, measure the diameter of the large face hole and the smaller edge hole. Record whether the edge faceplate has square corners, radius corners, or a drive-in latch.
On a mortise door, record the lock-case height, depth, width, faceplate size, spindle height, cylinder position, and pocket depth. A mortise case cannot be reduced to a single bore diameter.
4. Lock-to-lock or handle spacing
If the door has a deadbolt above a handle, measure centre-to-centre spacing between the two openings. An integrated smart lock may require a specific spacing even when a separate smart deadbolt and handle would fit.
For a lever or mortise arrangement, record the relationship between the handle, cylinder, thumbturn, and any lower or upper locking points. If the door uses a multi-point mechanism, note the handle lift or lock sequence instead of assuming a standard deadbolt action.
5. Flat mounting width and nearby obstructions
Measure the flat surface available around the lock centreline. Include the distance to the door edge, glass, raised panel, molding, frame, weatherstrip, hinge-side trim, and any nearby handle.
The lock body may be within the thickness range but still fail to sit flat. The AUSLOCK selector is useful as a reference because it asks for both door thickness and door stile or flat mounting width rather than treating thickness as the only fit variable.
6. Strike, frame, and handing
Measure or photograph the strike plate, pocket depth, frame condition, and latch/bolt alignment. Record whether the door opens inward or outward and which side the hinges are on.
A smart lock should not be calibrated against a door that already binds. Test the existing mechanical lock with the door open and closed, then correct sag, weather pressure, strike position, or frame damage before diagnosing the electronic product.
7. Interior clearance and cylinder projection
Look at the inside face, not only the exterior. Measure the space below and beside the lock for a battery cover, thumbturn, cable, mounting plate, or handle movement.
For a retrofit cylinder product, record the inside and outside cylinder dimensions from the centre reference, including any existing metal protection or hardware. Netatmo’s measurement guidance illustrates why inside and outside dimensions can matter separately on cylinder-based locks.
Use the Model Document as a Pass, Review, or Stop Gate
After collecting the measurements, do not average them into one “standard door” description. Compare each field with the exact model’s installation manual, template, or dimensioned datasheet.
| Result | Meaning | Action |
|---|---|---|
| All required fields match the model document | The door is a candidate for the stated route | Confirm the installation template and proceed to sample or installation planning |
| One dimension is outside the published range | The standard route is not confirmed | Request an approved accessory, alternate model, or technical review |
| The door route is unclear | The numbers may describe the wrong hardware family | Send photos and the edge/face details before selecting a product |
| The product page says “universal” but provides no dimensioned template | Compatibility is not sufficiently documented | Request the model-specific preparation sheet |
| Mechanical lock binds before electronics are installed | The door/frame problem is unresolved | Repair or align the door first; do not use motor calibration as a test fixture |
Manufacturer examples show why this gate matters. Lockly publishes bore, backset, thickness, and lock-spacing requirements for its own routes; Bold measures inside and outside cylinder dimensions for its own adjustable cylinder system; Yale provides a door-measurement template for its own smart-lock preparations. These documents are examples of model-specific evidence, not universal industry limits.
What to Photograph and Send with the Measurements
Numbers are easier to interpret when the supplier can see the hardware relationship. Take clear, square-on photos in good light, and include a ruler or tape measure in at least the close-up images when scale is important.
- Outside face showing the complete lock, handle, glass, panel, trim, and nearby obstructions.
- Inside face showing the thumbturn, cylinder, battery area, handle, and available clearance.
- Door edge showing the latch or lock case, faceplate, door material, and reinforcement.
- Frame and strike showing the pocket, alignment, weatherstrip, and door stop.
- Close-up of the bore, cylinder, spindle, tailpiece, or existing adapter after removal if removal is safe and authorized.
- One wider photo showing the whole door and the surrounding frame or adjacent glass.
Do not use a product photo as a substitute for the door photos. The purpose of the set is to reveal conditions that a number cannot describe, such as a narrow stile, a deep mortise, a raised panel, an anti-pull cylinder guard, or a battery cover that would hit the handle.
The Smart-Lock Door Measurement Sheet
Copy this block into a supplier email, sample request, or project record:
Target market:
Door application: residential / apartment / rental / hotel / office / other
Installation route: new-build / full replacement / retrofit
Door material and construction:
Lock route: bored deadbolt / tubular / mortise / Euro cylinder / rim / glass / narrow-stile / sliding / other
Door thickness at lock rail: ____ mm / ____ in
Fixed trim, plates, overlays, or weather seals:
Backset or cylinder reference measurement:
Cross bore / face bore:
Edge bore / latch bore / mortise case:
Lock-to-lock or handle spacing:
Flat mounting width and nearby obstructions:
Strike, frame, handing, and opening direction:
Inside/outside cylinder or tailpiece projection:
Interior clearance for battery, thumbturn, cable, and handle:
Existing lock brand/model, if known:
Photos or drawings attached: outside / inside / edge / frame / strike / close-up
Requested access methods and platform:
Sample quantity and expected repeat quantity:
Required model documents, accessories, or local installation rules:If a field does not apply, write “not applicable” rather than leaving it blank. A blank field can look like an overlooked measurement; an explicit “not applicable” records a decision about the door route.
From One Door to a Repeat-Order Project
For an individual replacement, the measurement sheet supports one model decision. For apartments, rentals, builders, or private-label programs, it becomes a configuration-control document.
Create one row per door family and group only when all of these are the same: lock route, thickness range, backset or cylinder position, bore or case, mounting width, trim, strike, handing, and interior clearance. Two doors can share a nominal thickness and still require different lock bodies or accessory sets.
Keep the approved sample’s photos, measurements, model number, installation template, accessory list, and hardware revision together. If the mounting plate, lock case, tailpiece, firmware-controlled calibration route, or exterior trim changes, repeat the fit review instead of assuming the previous approval still applies.
For standard residential doors, the next commercial step is to review Options de serrures intelligentes pour particuliers with the completed data. For a non-standard lock body, market-specific preparation, or private-label program, use the OEM/ODM smart lock route and send the measurement sheet before requesting a quote.
Foire aux questions
Do I need to remove the existing lock before measuring?
Not always. Many measurements can be taken with the hardware installed, but cylinder length, tailpiece, mortise case, and hidden reinforcement may require removal or a model-specific measuring tool. Do not remove hardware from a fire-rated, access-controlled, rented, or security-sensitive door without the required authorization.
Can I measure a smart-lock door with only a tape measure?
Often, yes for a first compatibility review. A rigid ruler, caliper, or supplied measuring template improves accuracy for bore diameter, cylinder projection, lock-case depth, and small clearances; photographs and the exact model template are still needed for final confirmation.
Are backset and door thickness the only measurements that matter?
No. Backset locates the lock mechanism relative to the edge, while thickness describes the slab span. Bore, edge bore, lock case, stile width, handle spacing, strike, handing, and interior clearance can still prevent a fit.
What if I do not know whether my door has a mortise or bored lock?
Photograph the open door edge and compare the hardware shape. A long rectangular case usually indicates mortise hardware; a smaller latch assembly connected to a round face bore usually indicates a bored route. If the image is ambiguous, send the photo before choosing a replacement family.
Can the same measurements be used for a glass or aluminum door?
Only the measurement discipline carries over. The lock body, stile or frame width, glass thickness, clamp/cutout, mounting surface, and safety or structural restrictions can be different, so use a product route that explicitly covers that door type.
What should I do when one measurement falls outside the model range?
Stop before drilling or ordering in quantity. Ask whether the exact model has a documented accessory or alternate preparation; otherwise choose a different lock route or request a technical compatibility review with the measurements and photos.
Conclusion
To measure a door for a smart lock, begin with the lock route, then record the door’s thickness, backset or cylinder reference, bore or lock case, lock spacing, flat mounting area, strike, handing, and interior clearance. Add photos that show the door faces, edge, existing hardware, and frame.
The completed record does not replace the model’s installation document, but it turns a vague “will this fit?” question into a checkable decision. Use the backset and door-thickness deep dives for the two measurements that usually receive the most attention, then send the full sheet for a residential or OEM/ODM compatibility review before committing to samples or bulk supply.
